Amp Shutting Down, need help


I have a Cary 7.250 brand new amp that shuts down after 20 seconds in my NYC apartment. I have sent the unit back to Cary where it tests fine. I have tried the unit at my friend’s apartment and his place of work and it works fine. The unit is 100% in working order. After talking to many people I was told to attach a 50' extension cord and low and behold it worked.

The good news is that I have a dedicated 20amp circuit to this outlet. My voltage reads 118 volts and Cary said that is not a problem as the unit will work between 90 and 130 volts. I have tested for voltage on the negative lead to ground and there is no stray voltage. I have also tried the unit on other outlets in the apartment and the same problem occurs.

My mono blocks and all other components work just fine. So I’d love to hear suggestions as to how to get rid of this 50’ extension cord?

Thanks in advance.
sailcappy
A line conditioner, my Classe' CA400 will not run off the crap that comes out of my wall either in my apartment.
What speaker cable are you using? Many solid state amps will not respond well to high capacitance speaker cable -- some will go into "protection" mode, as yours is doing. Speaking very generally, many flat cables and many skinny/round cables are high capacitance.
Great idea's.
1. Synergistic Research Powercell 10se MKII and the Cary will not work if it plugged into it or not.

2. The Cary will not work if it has all the speaker and interconnects attached or even if all the cables are not attached. As a matter of reference all of my interconnects and speaker cables are Crystal Cable Micro's.

3. I am using a 20 amp Maestro outlet.

Any other thoughts?
Hi 'Cappy.

Just to confirm; you're stating that the Cary still shuts down after 20 seconds without *any* cables connected except the power cord? If so, please bare with me with the following request:

Can you please re-confirm that your wall outlet(s) are wired and grounded correctly. You stated you're getting 118 volts between the HOT (smaller slot) and NEUTRAL (larger slot), and no stray voltage between the NEUTRAL and GROUND. Assuming your smaller slot is wired HOT, measure the voltage between it and the GROUND. If your apartment is wired correctly within the breaker box, you should read the same 118 volts as well since the NEUTRAL and GROUND should be connected together within the breaker box in most areas (I believe). *Some* equipment topologies require a properly polarized and grounded source to operate, hence, not to assume all is right even though other equipment designs will operate.

Please advise,
Metro04 - First off thank you very much for your insight. I had my friend who is knowledgeable about power test the lines and he confirmed that the polarity is correct vs. the small and large slots. He also noted that none of my outlets in my apartment are wired to ground it seems the ground is left to the junction boxes alone.

Where to go from here?
Cappy, *maybe* your grounding situation could be the culprit, though since I lack any knowledge regarding Cary's circuits, it might be worth a quick phone call to them for verification.

The only other thing I can think of is that your power cord might be wired backwards (if removable). I assume you've tried swapping it out with one or two other replacements as wiring mistakes do happen whether hi-end or cheap molded variants. Lots of equipment can still operate if reversed, but some circuit designs may take issue.

Also, since you haven't confirmed my question pertaining to your Cary being powered up with *no* input or speakers cables attached, have you tried powering it up with *only* speakers connected (no inputs)? Have you tried swapping speakers and speaker cables - independantly - just for troubleshooting sake (even using cheap speakers and lamp cord)? Note: The amp may not operate without speakers connected, and may trip off as well. See the operation manual for any warnings regarding operation without speakers connected.

Final advice; Be as systematic as possible while troubleshooting, change only one item at a time, and don't *assume* anything. After that, if you're *absolutely* sure every thing's wired correctly (including your AC), and Cary states your grounding configuration doesn't pose an issue, maybe someone else may have additional experience regarding acceptable DC percentages, if present.

In touch,
Thank you again for your suggestions! I am being extremely systematic and it never hurts to hear that over again:)

• I have tried two different power cords, the polarity on both of the power cords is correct
• The outlet polarity is correct. I have tried 4 different circuits in my apartment and the problem still occurs.
• I tried with and without speaker cables including lamp cord.
• It seems that none of my outlets have separate ground wires. I will call Cary today to discuss.
• Remember the unit works perfectly with a 50’ extension cord attached. WHY OH WHY does this work?
• My gut tells me that somehow I am getting dirty (do you love my technical term) electricity which causes the Cary to feedback and trip the 15amp circuit breaker. Remember the circuit breaker trips after 20 second after the unit is powered on.

To be continued……
After talking to many people I was told to attach a 50' extension cord and low and behold it worked.

What does the 50' extension cord add to the equation?

Impedance is the only thing that I can think of.....

The 50' cord increases the total length of the branch circuit feed to the amp.... ????

Was the only thing that was plugged into the end of the 50' cord the Cary amp?

If yes, it is possible the 50' cord/added impedance is some how decoupling the Cary power supply from some other piece of audio equipment that is fed off the same branch circuit the Cary is plugged into. ????

I would like you to do a test.

Unplug all your audio equipment from the dedicated 120V 20 amp branch circuit. You can leave the ICs connected to the Cary amp.

Now plug the Cary Amp directly into the wall receptacle of the 20 amp dedicated circuit. (The Cary is the only thing that is plugged into the duplex receptacle.)

Turn on the amp...... Post back your results.
.
I plugged the Cary amp directly into the 20 amp branch circuit; with and without interconnects and with and without speaker cables. Nothing else was plugged in to the branch. The 15amp circuit breaker (which is the on off switch for the amp) blows after 20seconds.

When I attached the 50' extension cord it only goes to the Amp and it works. Nothing else was attached to the extension cord and it worlks when all my other audio gear is plugged in as well.
The 15amp circuit breaker (which is the on off switch for the amp) blows after 20seconds.

Now that is a horse of a different colour!

Primary winding inrush current draw of the power transformer/charging electrolytic power supply caps is causing the circuit breaker on the amp to trip open......

The 50' cord is working like a soft start circuit limiting the inrush current draw to the Cary amp. At least that is what it sounds like to me.

What can you tell me about the 120V 20 amp dedicated branch circuit.
Distance from the electrical panel?
Wire size?
Electrical panel manufacture?

Another test....

Multimeter set to AC volts.
Insert the test probe leads into the unused receptacle of the duplex receptacle. Make note of the voltage reading. Cary plugged into the other recept.

While watching the meter flip the switch on the Cary to the on position. Note the reading/s of the meter.

Does the voltage sag several volts and remain low until the amp's breaker trips open? Voltage reading/s?

OR

Does the voltage sag and then swing higher than the original no load voltage? Voltage reading/s?
.
Well, I'm out of ideas without being there - armed with test equipment. The fact that it works at Cary, and your friend's location(s), without the addition of extra impedance (wire length), clearly indicates some thing's up with your apartment wiring, or induced noise.

08-14-12: Sailcappy
"He also noted that none of my outlets in my apartment are wired to ground it seems the ground is left to the junction boxes alone."

By that, I assume your outlets and junction boxes are grounded via metal conduit per local code? I'd have a warmer fuzzy if I knew the LINE/NEUTRAL voltage or resistance, and would still contact Cary to enquire about any grounding sensitivity issues with their circuits. As far as the level of noise it would take to cause your situation, is most intriguing.

The fact that numerous people suggested adding a 50' extension cord is interesting as well.

Besides Jea48, maybe member "Almarg" could offer some suggestions.

If you do get it resolved, be sure to post your findings.

Good luck
Jea48 - I can not thank you enough for your help.

1. No markings on breaker box at all. Building built in the 1970's
2. Outlet is about 40' from breaker box.
3. I was incorrect, there are 4 outlets on the branch but nothing is plugged into them.
4. The White and Black wires connected to the circuit breaker seem to be 10 guage.
5. I plugged the volt meter into the unused receptical next to the one the Cary was pluged into. With nothing else going on the voltage goes from 117.9 to 118.1. When I switched the Cary on the voltage did not change. Nor did it change during the 20 seconds it takes for the 15amp Cary breaker to trip. However when the breaker did trip for a split second the votage meter read 112 volts. I was able to re-create the same readings after 4 tries.

This is my friends theory. He works for the local power company. Let me know your thoughts.

"The breaker is a thermo-magnetic breaker and I think when the amp relays click off after it is done charging the caps, the break in load (which is not a smooth wave either) is sending a fluctuation back out on the incoming power that is causing the breaker to think there is an over current and trip. You should talk with Cary, but the solution may be to use a thermal breaker rather than one that is operated magnetically. The fact that the extension cord solves the problem supports this theory. The extension cord acts like a filter so when the amp relays open, it resists any power fluctuations on the line and therefore limits the magnetic field created on the breaker tripping mechanism."

I just want to listen to music :)
Hmmm, as you stated, it acts the same way from your 15 amp circuit as well as your dedicated 20 amp, yet works fine at Cary and your friends location(s) without the extension cord - when considering your friend's theory.

Jea48: As you know, "inrush" current is typically instantanious - with PS filter caps charged to 95+% within a few seconds, or so, for most high-power amps. Note he's stating the breaker consistantly trips "after 20 seconds", and even from several of his apartment's pre-wired standard 15 amp outlets. His recent noted voltage drop to 112, only at the moment of trip, is curious. For a thermo-magnetic breaker, you'd expect to see sustained high current voltage drop right up until tripping vs the virtually unaffected static 118 - as if the power supply wasn't even pulling current (?).

I just took a look at Cary's online PDF Owners Manual for anything of interest and there's not much to assist.

http://www.caryaudio.com/pdfs/manuals_2012/Model7.250_manual.pdf
4. The White and Black wires connected to the circuit breaker seem to be 10 guage.

Is the breaker a GFCI (Ground Fault Circuit Interrupter) or an AFCI (Arc Fault Circuit Interrupter)? These type of breakers have a test trip push button on them.

When I switched the Cary on the voltage did not change. Nor did it change during the 20 seconds it takes for the 15amp Cary breaker to trip.
Well that is good for the integrity of the branch circuit wiring. That tells me with the load connected the branch circuit maintained the supply voltage with little or no VD, (voltage drop) through the high inrush current cycle.

That also tells me the branch circuit is capable of delivering the inrush current draw of the primary winding of the power transformer.

However when the breaker did trip for a split second the votage meter read 112 volts.
I have a feeling the VD drop happened before the trip.....
Question is what is it and why?

At this point it would be good to hear from Almarg or Ralpf of Atma-Sphere Music Systems.

As for your friends theory he could be onto something.

By chance does your friend have a clamp on amprobe so you could measure the inrush current draw of the amp on startup?

As for the circuit breaker used on the Cary.... Is the switch actually a breaker? The handle trips position and has to be reset? If it is indeed a breaker the more times it is tripped the weaker it becomes.

Just can't beat a fuse for overcurrent protection for audio equipment.....
Jim
Jea48: As you know, "inrush" current is typically instantanious - with PS filter caps charged to 95+% within a few seconds, or so, for most high-power amps.
08-15-12: Metro04

Note he's stating the breaker consistantly trips "after 20 seconds",
08-15-12: Metro04

Metro04,

Good point....

His recent noted voltage drop to 112, only at the moment of trip, is curious.
Agree.....

For a thermo-magnetic breaker, you'd expect to see sustained high current voltage drop right up until tripping vs the virtually unaffected static 118 - as if the power supply wasn't even pulling current (?).

Are we 100% sure what the trip mechanism is?

The fact that the 50' extension cord allows the amp to work without tripping the overcurrent protection is baffling to say the least.

Like I said earlier it could be working as a current limiter... I am not so sure now, that is case...



If Sailcappy lives in a high rise apartment building hard telling what the power quality of the AC power looks like.

I wonder if Sailcappy has talked to the superintendent or head of maintenance about his problem? They may split the cost for a "Power Quality Company" to check out his mains power quality.

Harmonics
http://p3-inc.com/whitepapers/harmonics.pdf
.
"Is the breaker a GFCI (Ground Fault Circuit Interrupter) or an AFCI (Arc Fault Circuit Interrupter)? These type of breakers have a test trip push button on them."

There are no test trip buttons on any of the circuit breakers in the breaker panel.

"As for the circuit breaker used on the Cary.... Is the switch actually a breaker? The handle trips position and has to be reset? If it is indeed a breaker the more times it is tripped the weaker it becomes."

Yes it is an actual breaker as the switch has to be switched back on to put the unit back into standby. I have had it replaced to no avail.

"By chance does your friend have a clamp on amprobe so you could measure the inrush current draw of the amp on startup?
"
He did use one yesterday I have forgotten the outcome and will ask him tomorrow.

I do live in a high rise and my building said and I quote "as long as the breaker is not tripping then we do not concider you to have a problem." So much for living in a "luxury building".
How do I contact Almarg?
"Is the breaker a GFCI (Ground Fault Circuit Interrupter) or an AFCI (Arc Fault Circuit Interrupter)? These type of breakers have a test trip push button on them."

There are no test trip buttons on any of the circuit breakers in the breaker panel.
08-15-12: Sailcappy

I asked because you said the black and white wires of the branch circuit went to the breaker.
4. The White and Black wires connected to the circuit breaker seem to be 10 guage.
When a GFCI or a AFCI breaker is used both the hot conductor and the neutral conductor, of the branch circuit, terminate on the breaker. The breakers have a white pigtail that extends to the neutral bar in the panel.

http://caryaudio.com/pdfs/manuals_2012/Model7.250_manual.pdf


How do i contact almarg?
08-15-12: Sailcappy
Well under the new Agon system you can not....

All you can do is hope Al reads this thread.....
.
Cappy, at this juncture, based on all the info you've responded with, I'll have to agree with Slikric3000's recommendation for a "line conditioner" or filtering. It's obvious the 50 foot extension cord is providing just enough filtering of noise to prevent your Cary from tripping, and based on the amount a 50 foot cord is accomplishing, you won't need much of a conditioner or filter providing you meet/exceed your amp's maximum current demands, which I couldn't locate in the owners manual.

You might also be interested in getting something for the upstream sources and preamp/processor since they would benefit the most from cleaner/stable AC. I don't have any experience with them, but you can search the Audiogon forums or other sources since I've seen this topic come up periodically regarding manufactures/models/types.

If you knew exactly what issues were plaguing your AC, you could better select what filtering topology is best suited (cost effective), then buy/treat it accordingly as there are simple products available for a fraction of cost consumer-targeted A/V types, but whatever fits your likings and wallet depth. There's quite a few manufactures making LC's; some with strictly-business cosmetics, some quite fancy with eye-candy appeal, and variances in between. Or, for a truly cost-effective option, find a high-wattage 50 ft. extention cord of color choice, coil-stack it neatly in a 8-10" diameter with cable-ties to retain shape, and hide it out of sight behind the amp. The coilded stack will even provide a higher lever of filtering. Done! Solved! (joking)

Keep us posted...
Love the colored cable idea! Not sure if I can get that by the wife factor!!!

Can you give me an idea of line conditioners vs the Syngergistic Research Telsa Powercell that i have? What do I look for in a line conditioner?
Things known.

From the Cary's owners manual.

*Uses a soft start circuit. That limits inrush current.
*Has built in DC offset filter protection. (That would be after the magnetic circuit breaker)
*Uses a magnetic trip circuit breaker. (Would not be my chose)

*Cary works fine elsewhere outside OP's apartment.
*Will not work anywhere on any branch circuit in the OP's apartment without the 50' cord attached.

*Cary will not work plugged into the Synergistic Research Powercell 10se MKII power conditioner.

More questions.

What is the conductor wire gauge of the 50' extension cord?

Is the 50' cord in a coil?
Roughly the diameter size?

A 50' coil with AC current passing through it is an air core inductor..... Inductive reactance....???

I do live in a high rise and my building said and I quote "as long as the breaker is not tripping then we do not concider you to have a problem." So much for living in a "luxury building".
Sailcappy

Well with a magnetic trip circuit breaker Harmonics can cause them to nuisance trip.

Sailcappy, you mentioned your friend works for a power company. Does he have access to test equipment to check the power quality of the power feeding your apartment?

http://www.copperinfo.co.uk/power-quality/downloads/pqug/31-causes-and-effects.pdf

Reading from the owners manual it talks about putting the amp in "standby" mode before turning it off with the switch/circuit breaker. Not doing so leaves the amp in "Active mode" state. I assume you are powering the amp down correctly.

I ask because of the test you performed where just as the breaker tripped you notice the voltage dipped from 118V to 112V. The VD, voltage drop, was due to a spike in current. Was it the protection relay switching in the Cary amp?

Can't say 100% the VD was due to the Cary or maybe due to a high current load turning on elsewhere in your apartment. Though what are the odds it happened at the same time the breaker tripped.
.
Cappy, I completely forgot about you mentioning the Cary still tripping when connected to your Syngergistic Research (line conditioner) back on 8/13, as Jea48 just recalled. So now I'm at a loss, and baffled further.

Like Jea48, I was going to ask if your friend was able to diagnose your AC health with more appropriate equipment to find out exactly what's going. That's really what needs to happen. Not that you couldn't hide the coiled extention cord in cosmetic, WAF-approved packaging - complete with a fancier output receptacle if desired. (marketing idea)

I guess I'm out of ideas for now, unless it's still ground-related, but will continue to loose a percentage of sleep each night until it's resolved.

~
Jim just called this thread to my attention, by posting in another thread I was participating in.

Sounds like he and Metro have made many logical suggestions, and I'm pretty baffled as well. But here are a couple of thoughts:
08-14-12: Sailcappy
I had my friend who is knowledgeable about power test the lines and he confirmed that the polarity is correct vs. the small and large slots. He also noted that none of my outlets in my apartment are wired to ground it seems the ground is left to the junction boxes alone.
08-15-12: Sailcappy
It seems that none of my outlets have separate ground wires. I will call Cary today to discuss.
1) What does this mean? Does it mean that the safety ground pin on the outlets is not connected to anything, so that the safety ground pin on the amplifier's power plug is not connected to ground through the power wiring? If so, that would be number 1 on my list of things to focus on in relation to the problem. It would also be a serious code violation and a serious safety hazard.

Perhaps the design of one of the amp's various self-protection mechanisms is such that it is not happy if the amp's chassis (which can be assumed to be connected to the AC safety ground pin on the power plug) is not properly grounded. By attaching the 50 foot extension, capacitance between the three conductors in the extension cord will result in the addition of a significant amount of capacitance between the amp's chassis and AC hot and AC neutral, which conceivably could lessen the sensitivity of the protection circuitry to the ungrounded or improperly grounded condition of the chassis.

2) I'll repeat Jim's question about how the extension cord is coiled. And an experiment I would suggest is to compare results between when it is in a coiled state and when it is stretched out as much as possible, with as much spacing as possible wherever different parts of the cord have to run in parallel with each other. That will lower the cord's inductance, and thereby reduce the filtering effects it will provide at noise frequencies. (The effects of the cord's inductance at 60 Hz will be negligible either way). So comparing results between the coiled and uncoiled configurations might help us to rule out or rule in power line noise as being related to the problem. I don't think we can totally rule out that possibility at this point, even though the problem occurs when the SR conditioner is used.

Good luck!

-- Al
Al, thanks for stopping by.

Early on, I've tried to get as much confirmation from the OP regarding his outlet wiring and grounding, and based on his two responses pertaining to his friend's testing/confirming, responded with an assumption that his outlets were grounding directly to metal wall boxes and conduit by design - negating the need for ground wiring - pending local codes (not confirmed by OP). Again, based on his knowledgeable friend's testing, can only "assume" satisfactory measurements were observed on all aspects, and though I still don't have a warm fuzzy, didn’t wish to dwell further.

I also assumed his friend owned the meter, early on, leaving the OP unable to do spontaneous additional testing if requested. Appears he does, and I'd really like *him* to re-check the voltage from the outlet's LINE (smaller slot), to the GROUND pin and report the voltage. He's previously stated there's no stray voltage between the NEUTRAL and GROUND, so I'd like him to check for "resistance" between the outlet's NEUTRAL (larger slot) and GROUND if able.

If all is up-n-up, I assumed his SR conditioner would have taken dealt with any line noise issues, so... (scratching remaining hairs)

Frank
Hi Al,

I hoped you would see my post.

As Metro04 pointed out more than likely the electrical equipment grounding conductor for the branch circuits is the metallic conduit, boxes, and fittings. Back in the 1970s that was acceptable per NEC and more than likely NYC codes. (Problem, years later, was the degradation of electrical continuity integrity from the fittings, connectors, lock nuts, and conduit couplings.

Corrosion for one, = resistance. If we have resistance then a difference of potential can exist from the grounded neutral conductor and the safety equipment grounding conductor at the branch circuit outlet device, the receptacle.

To rule any chance of noise on the safety equipment ground I would think, for test purposes, a ground cheater could be installed on the power cord of the Cary Amp.

What are your thoughts on the magnetic field of the 3rd and 5th harmonic on the relay solenoid of a magnetic breaker? I would think it would distort the actual current passing through the switch/magnetic breaker on the back of the Cary amp.

Harmonics is about the only thing I can think of that causes the Amp's magnetic breaker to trip in the OP's apartment but no where else outside of his apartment.

The fact that the 50' extension cord stops the nuisance tripping is interesting.....

I assumed the cord is coiled up and not laying out in the room. Appearance as well as being a trip hazard.

So, to me, at least two things are at play.
Size of the conductors of the cord.... Impedance....
Cord is coiled up...... inductance.....

Does that filter out harmonics or at least lessen the effect on the magnetic field of the solenoid of the magnetic trip of the breaker?

I asked the OP in a previous post if he was shutting down the Cary Amp by first pushing the power button on the front panel of the Cary putting the Amp in standby before turning off the power switch/breaker on the back of the amp. (Not doing so leaves the amp in the "Active Mode" state.)

The owners manual recommends not shutting off the amp without first putting the amp in standby.

With the problem the OP is having, unique only with his apartment, proper shutdown and power up could just be enough for the breaker to hold.

I would recommend the OP power up the amp with the 50' extension cord power off by putting the amp in "standby" first then turn off the switch/breaker.

Remove the 50' cord and plug the amp directly into the wall receptacle. Wait at least 5 minutes to power up the amp again. (Power supply caps should be bled off by then?)

I would then turn on the switch/breaker and see what happens. Hopefully the 20 second timeline will pass with no breaker trip event.

If the breaker does not trip, fingers crossed, I would not get in any big hurry to push the power button on the front of the amp that starts the sequence to power up the amp in the "Active Mode". Wait at least a few minutes or so.

If the amp does power up I would not power the amp totally down unless going on vacation or in the event of lightning storms. I would just push the power button on the front of the Cary putting the amp in standby.

Does it totally solve the OP's no.... And sad to say he would still need to keep the 50' extension cord. If he has a power outage the amp will be set to "Active Mode" and he will have to use the 50' cord to to reset the amp to standby.
Jim
I assumed his SR conditioner would have dealt with any line noise issues ....
My instinct (based on nothing specific) is to not make that assumption, especially given that detailed design information and quantitative test results appear to be unavailable for that (and most other) conditioners.

The kind of possibility I'm envisioning is that some piece of industrial-type equipment somewhere in the building, or nearby, is putting a significant voltage spike onto the AC, that repeats each cycle, and whose characteristics are such that the conditioner is ineffective against it.

Sailcappy, is there any chance that you can borrow a different conditioner from someone? Also, if by any chance you know someone who has an oscilloscope, and is knowledgeable about how to use it, a good experiment would be to view the AC waveform on it, and set it to trigger at a level a little higher than the nominal peak of the AC waveform (which is around 170 volts). Then see if it triggers, and what it captures if it does trigger.

Best regards,
-- Al
I just spoke with my friend who works for the power company and we agreed on the following:

1. Regardless of the problem with my buildings power we know they will not fix it.
2. It seems to me that some type of power regenerator is needed.
3. What do you recommend that just has one input and one output?
4. Should I go digital or analogue?

Thanks again for all your help!
Jim, I didn't see your last post until just now; sorry. I guess it must have gone up just a few seconds before my last post.

You've offered lots of good thoughts and suggestions. My only further comment is that while I'm not particularly familiar with magnetic breaker characteristics, I'm skeptical that relatively low order harmonics are to blame. The reason I say that, and I could be wrong, is that I doubt that the inductance of a coiled 50 foot extension cord would be significant enough to have much effect at those kinds of frequencies. Keep in mind that the inherent inductance of each individual conductor (hot and neutral) will be significantly reduced by the fact that the other of those conductors is in close proximity. Coiling will increase the inductance, of course, but it will be multiplying an amount that is much less than if just one of the two current-carrying conductors were present in the cord.

So my guess, and as I say I could be wrong, is that as I suggested earlier there is some sort of higher speed transient that is present, that repeats each cycle and that is being reduced by the extension cord's inductance. Or, alternatively, perhaps the capacitance between the safety ground conductor of the extension cord and the other two conductors is providing some sort of filtering action at high frequencies, or is somehow affecting something in the amp by adding capacitance between the chassis and the AC inputs.
08-20-12: Sailcappy
I just spoke with my friend who works for the power company and we agreed on the following:

1. Regardless of the problem with my buildings power we know they will not fix it.
2. It seems to me that some type of power regenerator is needed.
3. What do you recommend that just has one input and one output?
4. Should I go digital or analogue?
Why invest in a power regenerator, and perhaps risk introducing side effects that on occasion have been reported to result from them (such as compromised dynamics), when you already have a solution that appears to work adequately?

And if a regenerator is to be selected, it would seem preferable to first have as good an understanding of the cause of the problem as possible. Meaning, IMO, that the measurements and experiments suggested by me, Frank, and Jim should be addressed first. Such as the simple ground measurements Frank suggested, the comparison I suggested of results with the extension cord coiled and uncoiled, and the suggestions in Jim's last post.

Otherwise we're taking a shot in the dark. Which we may end up taking anyway, but it would be prudent to minimize that likelihood as much as possible.

Regards,
-- Al
Thank you for reminding me of proper trouble shooting techniques. Last night I had one to many and when my friend and I got around to dealing with this issue we both just said screw it just purchase a regenerator. And we went back to drinking. LOL.

Moving forward instead of referring to my friend as the guy who works for the power company I will use his first name which is Ken.

Back to the problem:

1. I uncoiled the extension cord and the Cary powered on without a problem. So it works both coiled and uncoiled.
2. The 50’ extension cord has the following information imprinted on the jacket 16/3. I assume that means 16 gauge times three wires. The jacket diameter is 5/16”. I’d have to cut the cord to get the actual gauge of the wire.
3. I have tried it with shorter extension cords from 3 feet to 20 feet with approximately the same diameter and it does not work.

“I ask because of the test you performed where just as the breaker tripped you notice the voltage dipped from 118V to 112V. The VD, voltage drop, was due to a spike in current. Was it the protection relay switching in the Cary amp?”

4. Not sure what you are asking the 15amp breaker which is the on/off switch for the breaker trips it to the off position when I noticed this drop. Remember this happends after i go from standby mode to Active mode.

"Does it mean that the safety ground pin on the outlets is not connected to anything, so that the safety ground pin on the amplifier's power plug is not connected to ground through the power wiring? If so, that would be number 1 on my list of things to focus on in relation to the problem. It would also be a serious code violation and a serious safety hazard.”

5. Ken confirmed that all of my outlets in the apartment are grounding directly to metal wall boxes and conduit by design - negating the need for ground wiring including the circuit breaker box.

"I'd really like *him* to re-check the voltage from the outlet's LINE (smaller slot), to the GROUND pin and report the voltage. He's previously stated there's no stray voltage between the NEUTRAL and GROUND, so I'd like him to check for "resistance" between the outlet's NEUTRAL (larger slot)and GROUND if able."

6. Voltage from the “smaller" slot to the "ground" slot is 118 volts.

7. Resistance (Using the Omega setting on the volt meter) between Neutral (Large Slot) and Ground slot jumps between 13 and 17 units.

"To rule any chance of noise on the safety equipment ground I would think, for test purposes, a ground cheater could be installed on the power cord of the Cary Amp. With the problem the OP is having, unique only with his apartment, proper shutdown and power up could just be enough for the breaker to hold."

8. I tied a ground cheater plug with the stock power cord and the problem occurred.

"I would recommend the OP power up the amp with the 50' extension cord power off by putting the amp in "standby" first then turn off the switch/breaker. Remove the 50' cord and plug the amp directly into the wall receptacle. Wait at least 5 minutes to power up the amp again. (Power supply caps should be bled off by then?) I would then turn on the switch/breaker and see what happens. Hopefully the 20 second timeline will pass with no breaker trip event. If the breaker does not trip, fingers crossed, I would not get in any big hurry to push the power button on the front of the amp that starts the sequence to power up the amp in the "Active Mode". Wait at least a few minutes or so."

9. The breaker only trips after I take the unit out of standby mode and put it into “Active Mode”. I am powering the amp in the following manner. I first turn the circuit breaker switch from the off position to the on position. I then press the button on the front of the unit which takes it out to standby mode into the Active Mode”. Without the extension cord the 15 amp ON OFF circuit breaker switch on the back of the unit trips to the off position. After it switched to the off position I put the unit back into standby mode (pressing the front button to standby) and start the process over again. Not sure if your reccomendation is valid.

"Sailcappy, is there any chance that you can borrow a different conditioner from someone? Also, if by any chance you know someone who has an oscilloscope, and is knowledgeable about how to use it, a good experiment would be to view the AC waveform on it, and set it to trigger at a level a little higher than the nominal peak of the AC waveform (which is around 170 volts). Then see if it triggers, and what it captures if it does trigger."

10. Ken is working on getting a oscilloscope to test

11. I don’t know anyone in NYC to borrow a different power conditioner. I will ask a dealer to see if they will assist.
2. The 50’ extension cord has the following information imprinted on the jacket 16/3. I assume that means 16 gauge times three wires.
Correct...

The cord impedance is limiting inrush current through the magnetic breaker of the Cary amp when the amp goes active.....


“I ask because of the test you performed where just as the breaker tripped you notice the voltage dipped from 118V to 112V. The VD, voltage drop, was due to a spike in current. Was it the protection relay switching in the Cary amp?”
jea48

4. Not sure what you are asking the 15amp breaker which is the on/off switch for the breaker trips it to the off position when I noticed this drop. Remember this happends after i go from standby mode to Active mode.
Sailcappy

The on/off switch/breaker is for FLA protection of the amp.
Short circuit and or overload condition.

The protection relay switches the amp from standby to active mode which I would assume sends power from the power supply to the power amps circuitry. The protection relay circuitry should also protect the speakers from damage in the event of amplifier malfunction.

Test.
With the 50' cord connected volume control set at minimum turn on the switch/breaker. With your ears close to the amp push the power button on the front of the amp. (Standby to active). More than likely you will hear a click/s.... That is the protection relay/s changing state.
"I would recommend the OP power up the amp with the 50' extension cord power off by putting the amp in "standby" first then turn off the switch/breaker. Remove the 50' cord and plug the amp directly into the wall receptacle. Wait at least 5 minutes to power up the amp again. (Power supply caps should be bled off by then?) I would then turn on the switch/breaker and see what happens. Hopefully the 20 second timeline will pass with no breaker trip event. If the breaker does not trip, fingers crossed, I would not get in any big hurry to push the power button on the front of the amp that starts the sequence to power up the amp in the "Active Mode". Wait at least a few minutes or so."
jea48

9. The breaker only trips after I take the unit out of standby mode and put it into “Active Mode”. I am powering the amp in the following manner. I first turn the circuit breaker switch from the off position to the on position. I then press the button on the front of the unit which takes it out to standby mode into the Active Mode”. Without the extension cord the 15 amp ON OFF circuit breaker switch on the back of the unit trips to the off position. After it switched to the off position I put the unit back into standby mode (pressing the front button to standby) and start the process over again. Not sure if your reccomendation is valid.
Sailcappy
When the breaker trips all power on the load side of the breaker is disconnected from the Cary amp. Pushing the standby push button on the front panel will not do anything. As I read the owners manual the amp is still in active mode.

From the owners manual.

"Power Button.
The Power Button performs no function when the amplifier is power off with the rear Master Power Switch.

When the rear panel master switch is powered on the model 7.25 is in standby mode. Pressing the Power Button when the rear panel mater panel switch is powered on will activate the power amplifier"..... And so on....

NOTE.
"When the status of the model 7.25 changes relay checks may be audible. This is normal operation."

I suggest you reread the owners manual again.
Section on, "Controls and Displays".


9. The breaker only trips after I take the unit out of standby mode and put it into “Active Mode”.
Sailcappy
Immediately after?

The 50' 16/3 power cord is limiting inrush current flow through the magnetic breaker.

.
Sailcappy, thanks for the additional info. A few things are not clear to me, though, which are along the lines of some of the questions Jim had.

1)If the extension cord is not being used, am I correct in understanding that the breaker on the amp trips 20 seconds after the amp is switched from standby to on/active (the rear power switch/breaker having been turned on previously)?

2)And when the extension cord is being used, will the amp play music during those 20 seconds, or does it really become active only after the 20 seconds have elapsed?

3)And as Jim asked, when the extension cord is being used do you hear the click of a relay at the 20 second point?

Regards,
-- Al
Hi Al,

By chance did you read the Cary owner manual?

http://caryaudio.com/pdfs/manuals_2012/Model7.250_manual.pdf

CAUTION.
If the unit is in active mode and power is removed, it will remain activated when power is restored.
>>>

So it looks to me after a forced shutdown, breaker trips, when the unit is reset and powered up, by resetting the breaker switch, the unit comes up active mode... Does the restart sequence take 20 seconds? Don't know....

OR

Does the breaker trip before the amp is "made" active?

What say you?
.
Jim
Hi Jim,

Yes, I did look at the manual. As you realize, though, it does not appear to provide enough information for us to infer answers to the questions in my previous post.
If the unit is in active mode and power is removed, it will remain activated when power is restored.
Yes, I noticed that both in the manual and in one of your earlier posts. But what I'm mainly looking to establish at this point is what the amp's normal turn-on behavior is, in the situation where the breaker had been turned off only after standby mode had been entered.

Which relates to your point about inrush current. It is not clear to me when the major inrush current normally occurs. Does it occur:

(a)When the breaker is turned on, assuming that the amp had been left in standby mode when it was previously turned off. Or,

(b)Does it occur when the amp is switched from standby to active? Or,

(c)Does it occur 20 seconds later?

A related thought that occurs to me is that I would not assume that the voltage drop that was observed as the breaker was tripping was due to inrush current that normally occurs at that point. It seems conceivable to me that contact bounce occurring in the breaker as it tripped might have resulted in inrush current and voltage drop that would not occur at that time ordinarily. So the voltage drop might have just been a consequence of the breaker tripping, rather than reflecting a large inrush current that may have caused the breaker to trip. Or perhaps some sort of inductive kickback effect from the power transformer or a relay was responsible for the voltage drop, given especially that the amp was not designed with the expectation that it would normally be powered down from the active state by means of the breaker.

Just some thoughts.

Best regards,
-- Al
You know, as I read through all of this which is way over my head technically, I wonder, as I have from the beginning of this thread, why the OP uses the mag breaker as an on-off switch? And could that not be the major part of the problem? has the OP tried shutting down using the standby switch w the ext cord, and then leaving the breaker in the on position, plugging the power cord, sans extension, back in and again powering up from the standby switch? Perhaps he has and I missed it.
Hi Al,

4. Not sure what you are asking the 15amp breaker which is the on/off switch for the breaker trips it to the off position when I noticed this drop. Remember this happens after i go from standby mode to Active mode.
08-21-12: Sailcappy
From what Sailcappy says in the quote above the breaker trips as the amp moves from standby to active.

So question is what all is powered in standby?
Just the power transformer?
Or the transformer and DC power supply?

Which relates to your point about inrush current. It is not clear to me when the major inrush current normally occurs. Does it occur:

Good question.... And then there is the soft start feature of the amp?
Where is the circuit installed. Does it limit, smooth out the inrush on initial standby start up only? Or both standby start up as well as active mode activation?

A related thought that occurs to me is that I would not assume that the voltage drop that was observed as the breaker was tripping was due to inrush current that normally occurs at that point. It seems conceivable to me that contact bounce occurring in the breaker as it tripped might have resulted in inrush current and voltage drop that would not occur at that time ordinarily. So the voltage drop might have just been a consequence of the breaker tripping, rather than reflecting a large inrush current that may have caused the breaker to trip. Or perhaps some sort of inductive kickback effect from the power transformer or a relay was responsible for the voltage drop, given especially that the amp was not designed with the expectation that it would normally be powered down from the active state by means of the breaker.
Agree... As I said in an earlier post it could have just been a coincidence at the same time some other load started and the VD occurred at the main electrical panel.

How about that 50' 16/3 extension cord??
Yes the cord is too small for the amp.... But what about what is it doing?

Two things come to mind. If the current does go up as the amp goes into the active mode then I would imagine the voltage drops. Available Power at the end of the 50' cord would be reduced. Enough so the amp is able to complete the process of going into active and playing music without tripping the magnetic breaker.

You stated earlier you thought the amp might be reacting to voltage transients and thus causing the magnetic breaker to trip.

Would a good SPD, surge protection device, installed between the amp and the wall outlet shunt out the high voltage transients?

One last thought I wonder if it would help if the hot conductor of the 20 amp dedicated branch circuit was moved to the other line, leg, in the electrical panel?
Jim

Look! Every time I get close to addressing and finishing a few paragraphs in response, all you guys quickly sneak in answers and more questions! So, I'll just sit patiently in the corner with a "filthy bed-wetter" sign on and wait fer a bit. :-D

Now, how the hell are you guys (Jim & Al) quoting in small font?

Frank
Hi Swampwalker,

I believe when the amp is first powered up using the switch breaker on the rear panel of the amp the breaker holds in the standby mode.....

The proper shut down procedure is to first push the power button on the front panel of the amp. That puts the amp in standby. The user can then turn off the amp with the main power switch/breaker on the rear panel of the amp or leave it on 24/7.

From what I have gathered from reading Sailcappy's posts, the amp could be left in standby indefinitely and not trip the magnetic breaker.

The problem starts when he pushes the power button on the front panel of the amp that starts the sequence from standby to active mode.

The switch/breaker is in series with hot of the 120V power.
That makes the breaker the gate keeper so to speak......
Jim
08-11-12: Sailcappy
I have a Cary 7.250 brand new amp that shuts down after 20 seconds in my NYC apartment.

08-21-12: Sailcappy
Remember this happens AFTER [emphasis added] i go from standby mode to Active mode.
Jim & Michael (Swampwalker), I've been interpreting these and other statements to mean that if the power switch/breaker at the rear of the amp has been properly turned off while in standby mode, and the rear power switch/breaker is subsequently turned on, and subsequent to that the front standby/active switch is turned to on/active, then 20 seconds later the breaker trips (if the extension cord is not used). That is what I was asking Sailcappy to confirm, in question (1) in my first post tonight.
Would a good SPD, surge protection device, installed between the amp and the wall outlet shunt out the high voltage transients?
Don't know. The oscilloscope experiment I suggested might help answer that.

Frank -- click the "markup tags" link just under the box near the bottom of the page in which responses are composed.

Have to sign off now until tomorrow.

Best regards,
-- Al
Look! Every time I get close to addressing and finishing a few paragraphs in response, all you guys quickly sneak in answers and more questions! So, I'll just sit patiently in the corner with a "filthy bed-wetter" sign on and wait fer a bit. :-D
08-21-12: Metro04
LOL......
To be very, very clear I will detail my power up process which is the same with and without the extension cord.

1. Prior to doing anything I check that the rear breaker On/Off switch is set to the off position and the front Standby/Active switch is set to the Standby position.

2. I then push the rear breaker On/Off switch to the On position.

3. I generally wait a little (I have varied the waiting time up to an hour) then I push the front Standby/Active button from Standby to Active.

4. I hear a lot of relay type clicking noises and the approx 20 seconds later if I do not use the extension cord the final click inside the amp trips the rear breaker On/Off switch to the Off position.

5. I then repeat this process every time I re-power the unit.

6. Music does not play during the first 20 seconds. When I use the extension cord after 20 seconds I get a final click that then allows music to play. It also turns on the LED light for the Cary Logo.
Sailcappy,

Thanks for the detailed start up procedure.

1. Prior to doing anything I check that the rear breaker On/Off switch is set to the off position and the front Standby/Active switch is set to the Standby position.

......"and the front Standby/Active switch is set to the Standby position."

Are you saying the front power switch is a maintained contact switch and not a momentary contact switch?

In other words the push button switch has two positions, in and out?

You did not give the shut down procedure but I assume you

put the amp in standby by pushing the power switch on the front panel first and then flip off the switch on the back panel.

6. Music does not play during the first 20 seconds. When I use the extension cord after 20 seconds I get a final click that then allows music to play. It also turns on the LED light for the Cary Logo.
So the final click is the killer.....

Have you thought about sending the Agon Link of this thread of yours to Cary service support?

A look inside of the Cary 7.25.
.
Sailcappy,

I forgot to ask. Is your friend, that works for the power company, an Electrical Engineer? An electrical technician?

The reason I ask is your friend qualified, confident, to preform work inside the electrical panel of your apartment?

Nothing major.... Just move the hot conductor of the audio 20 amp dedicated circuit to another 20 amp breaker on the other Line, leg, bus in the electrical panel. (Providing there are any spares. If there is not a spare he could use a breaker that is being used, for the test.)

If you are not sick of tests yet one more test you could try......

If the problem is poor power quality you could rule out the offending electrical device/s, equipment, appliances, CFL lights, ect, in your apartment is the cause.

You will need a flash light....
Turn off ever breaker at the electrical panel except the main breaker, if you have one, and the breaker that feeds the dedicated circuit to the Cary amp.

I lied, one more test. I would sure like to know what the VD, voltage drop, looks like at the end of the 50' 16/3 cord as the Cary amp is going through it's active start up cycle...... Especially that last relay click you hear.

If the 50' cord only has a single female receptacle you would need an additional receptacle to plug in the test leads of the multi meter. You could use a plug strip for the test? (Plug strip plugged into the 50' cord.)
.
Is the AC cord plugged in on the same side of the line as the preamp and front end of the system?
Are you saying the front power switch is a maintained contact switch and not a momentary contact switch? In other words the push button switch has two positions, in and out?

• The front switch has two positions (though very subtle) either pushed in for Active or out for Standby.

• With the extension cord attached the rear On/Off breaker remains in the On position. My current operation (again with extension cord attached) is to only to change the unit from Standby to Active and visa versa when I want to listen to music or not. I never touch the rear circuit breaker On/Off Switch I leave it in the On position.

Have you thought about sending the Agon Link of this thread of yours to Cary service support?

• I will send it to them and I have been keeping them in the loop with no feedback as of late.

The reason I ask is your friend qualified, confident, to perform work inside the electrical panel of your apartment? Nothing major.... Just move the hot conductor of the audio 20 amp dedicated circuit to another 20 amp breaker on the other Line, leg, bus in the electrical panel. (Providing there are any spares. If there is not a spare he could use a breaker that is being used, for the test.)

• He said all the wires are live coming in to the breaker box and it is not a good idea to switch them as there is no way to kill the current coming into the box.

Turn off ever breaker at the electrical panel except the main breaker, if you have one, and the breaker that feeds the dedicated circuit to the Cary amp.

• I turned off all circuit breakers and unplugged everything I could physically remove from every outlet in the apartment so that just the Cary was plugged into the wall without the extension cord. The Cary On/Off breaker blew as usual after 20 seconds after I went from Standby to Active mode.

I would sure like to know what the VD, voltage drop, looks like at the end of the 50' 16/3 cord as the Cary amp is going through its active start up cycle...... Especially that last relay click you hear

• I attached a three way strip I had lying around into the end of the extension cord. I then plugged the Cary into one of the sockets and the voltage meter into the other.
• When turn the circuit breaker from Off to On the voltage at the end of the extension cord does not change. It remains at 118 volts. When I press the front button from Standby to Active the voltage remains at 118 volts for the 20 second duration. At that last relay click (at about 20 seconds) the voltage dropped from 118 volts down to 115 volts for split second and then back up to 118 volts.

Is the AC cord plugged in on the same side of the line as the preamp and front end of the system?

• All of these tests are performed with just the Cary plugged into the outlet and nothing else.
Getting back to the ground issue:

I have a great ground on my apartment terrace. It is a lightning rod building ground cable. I assume you can't get any better ground than that. Since the ground for all my outlets is through the conduit and outlet boxes should I somehow attach a wire from the lightning rod ground to the outlet box or green connector on the outlet? Not quite sure from earlier posts what I was supposed to test.

Thanks!
I don't think the ground is the problem.

Here is my theory:

Right now I think there might be DC on the line. DC can cause a toroidal transformer to saturate. Now what if its not very much DC, less maybe only about .3 to .5 volts...

In standby the amp might be OK. At full power the toroid saturates and the resulting inrush blows the breaker.

By adding the power cord there is enough voltage drop and resulting reduction in current inrush that things hold up.

In other places tried there is no DC on the line.

DC is a good culprit as we are talking about multiple dwellings in a single building.

There are 3 solutions I can think of:

1) have a current inrush limiter installed ()this might allow the amp to power up but I bet the transformer will be mechanically noisy)
2) have a DC blocker circuit installed (a rectifier bridge bypassed with electrolytic caps of the right value) We are talking about $15-$20 worth of parts. This is something I would have Cary do.
3) use a DC blocker with the circuitry of 2) in it.

You could test this theory by getting the DC Blocker of 3) and seeing if it sorts things out. If it does, I would have the amp modified by Cary to have these parts installed. Its an easy fix.
Sailcappy,

No I would not use the lightning bare 4/0 ground wire for an auxiliary equipment ground..... That could open up a whole new can of warms.

• I attached a three way strip I had lying around into the end of the extension cord. I then plugged the Cary into one of the sockets and the voltage meter into the other.
• When turn the circuit breaker from Off to On the voltage at the end of the extension cord does not change. It remains at 118 volts. When I press the front button from Standby to Active the voltage remains at 118 volts for the 20 second duration. At that last relay click (at about 20 seconds) the voltage dropped from 118 volts down to 115 volts for split second and then back up to 118 volts.
08-22-12: Sailcappy
Well I would bet the switch/breaker on the back of the unit is nothing more than a main power breaker/switch disconnect.

The maintained contact standby/active mode switch is in series with the rear panel breaker/switch. All amplifier loads are fed off this switch.

The soft start circuit, along with, I would imagine active sequence staging start up, keeps inrush currents controlled from the voltage readings you supplied. A 3 Volt VD on a 50' 16/3 cord is incredibly low to say the least.

Just curious is the multi meter voltage section reading true RMS?

One other test I should have mention is to check the VD with the amp playing music from a dynamic music source with the volume level set where you normally listen to music. IF the voltage were to sag below the safety limits of the amp, because of the VD of the extension cord, the amp could be damaged. If you do the test watch the meter to see if it moves around with the dynamics of the music material. Hard to believe the dynamics of the amp does not suffer because of the 50' 16/3 cord.......



The reason I ask is your friend qualified, confident, to perform work inside the electrical panel of your apartment? Nothing major.... Just move the hot conductor of the audio 20 amp dedicated circuit to another 20 amp breaker on the other Line, leg, bus in the electrical panel. (Providing there are any spares. If there is not a spare he could use a breaker that is being used, for the test.)
jea48

• He said all the wires are live coming in to the breaker box and it is not a good idea to switch them as there is no way to kill the current coming into the box.
Sailcappy

Your friend does not feel safe working on the inside of a live electrical panel and that is fine.....
Better safe than sorry.....

You would need to hire an electrician to do the test for you.

Atmasphere,

The Cary 7.250 has a built in DC blocker as well as a soft start circuit.
Jim
First off, Sailcappy, I (we) appreciate your patience and cooperation with all the requests from "The Brain Trust" (SCRUBS). Other than Jim's latest request(s) below, and based on what’s been tried and confirmed so far, I think we all will agree that an oscilloscope would be beneficial/essential at this juncture to diagnose mutually-suggested D.C. and noise suspicions, of which you mentioned that your friend, who works for the power company (aka;” Ken”), was trying to obtain one.

08-22-12: Jea48 “…Just move the hot conductor of the audio 20 amp dedicated circuit to another 20 amp breaker on the other Line, leg, bus in the electrical panel. (Providing there are any spares. If there is not a spare he could use a breaker that is being used, for the test.”
and...

”I would sure like to know what the VD, voltage drop, looks like at the end of the 50' 16/3 cord as the Cary amp is going through its active start up cycle...... Especially that last relay click you hear.”

Jim, wouldn’t his other “standard 15 amp” outlets, throughout the apartment, be split up between the two incoming legs? He has tried, unsuccessfully, to energize the amp from various 15 amp locations around the apartment, though it isn’t known how they are split up.

Frank

PS; Thanks Jim/Al for the "quoting" assistance. I'll take my sign off.
Jea48, thanks for that note. In that case, I suspect that the DC blocker circuit has developed a malfunction. It would not be missed if the AC line were clean.

Its easy enough to test for. There is someone on this forum who makes AC extension outlets that have the DC Blocker built in. Just use one of those and you would know if that's what it is.

The lack of AC grounds in the wiring is disturbing, but it should not cause any troubles with the amp.
08-18-12: Metro04
"I'd really like *him* to re-check the voltage from the outlet's LINE (smaller slot), to the GROUND pin and report the voltage. He's previously stated there's no stray voltage between the NEUTRAL and GROUND, so I'd like him to check for "resistance" between the outlet's NEUTRAL (larger slot)and GROUND if able."

08-21-12: Sailcappy
“6. Voltage from the “smaller" slot to the "ground" slot is 118 volts.
7. Resistance (Using the Omega setting on the volt meter) between Neutral (Large Slot) and Ground slot jumps between 13 and 17 units.”

08-22-12: Atmasphere
“The lack of AC grounds in the wiring is disturbing, but it should not cause any troubles with the amp.
Atmasphere, This was something I pushed to verify - lacking any knowledge of Cary’s circuit topologies - and *can* be of issue with some equipment designs (audio equipment aside). Sailcappy’s stated measurement of 13-17 ohms seems a tad bit high for 10 AWG, but based on the Neutral wire’s length alone, and various metal conduit mechanical connections, might be expected. Really don’t know for absolute if that amount of resistance poses an issue for that *particular* amp.