Backup Generator transfer switch

In the past two issues of Stereophile, Michael Fremer has been discussing the disastrous results to the sound of his system after having a backup generator installed at his home. The system is not running on the generator, but he believes it has to do with the transfer switch that gets installed on the AC signal path.  He describes a pre-generator experience as "intense and emotionally elevating" afterwards "everything good was gone, two large ill-focused boomboxes had replaced absolute magic".  I recently moved and had been listening to my system prior to and after the installation of a Generac whole house generator, I did not notice any change in the sound, I can still sit and enjoy the music for hours with no sense of fatigue.  Perhaps my ears are shot or my equipment is not expensive enough.  Anyone here have any experiences with generator transfer switches?

Ag insider logo xs@2xdeadlift
My transfer switch didn't cause any issue, but I wouldn't expect it to. My system's dedicated lines don't go through the switch.
I’m sorry to not have experience to share but I was disturbed by Fremer’s situation. Glad to hear that your power matrix is not interfering with your musical enjoyment.
As cleeds reports it should not be a problem if you don't attempt to setup for music during a power grid failure.
What cleeds did is exactly what Fremer is having done - setting up another circuit for his audio bypassing the transfer switch.
I had a backup generator installed recently and notice no degradation of sound.  I have also had dedicated lines For years, my system sounds tremendous.  
In the last issue Fremer backtracked somewhat on his comments.  The system still sounded really good, but just not outrageously excellent.
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I do have my entire system connected to a Shunyata Research Denali V2 power distributor so maybe that’s the difference.

I had the PD before installation of my Generac 25kw stand by generator and as I said I noticed no difference.  Then again I have a mere mortals system compared to him.  

I am sure Mike F. Is not imagining the difference in his system.  Unless maybe he is, but he sounds convinced.  
I have a whole house generator behind my home and the generator is run on propane. I hear no difference (Thank God!) with the transfer switch. I do have 2 dedicated 20 amp lines for my system. I
never run my system or TV off the generator though.
I have a similar ATS, although mine is in the basement right next to the panels not outside. Fremer does add towards the end of his last article in Stereophile that it could have something to do with having over $800,000 dollars of a system (some of which is review products) and more expensive equipment can be more sensitive to issues.....Nothing I'll have to worry about.
I plan to install a Generac whole house after the disaster here in Texas and will be digging down with the same electrician that installed the subsystem I use to power the hi-fi, which is essentially a 60 amp feed from the main service entrance to a sub panel that goes into a 10kVA iso transformer and routes via 4 gauge to a sub panel dedicated to the system and from which are pulled dedicated lines. 
I have no interest in playing the system during any electrical back up period, but the Fremer experience was brought to my attention. Given that virtually all this electrical equipment is outside in close proximity to the service panel (no basement, just pier and beam construction), it should be possible to route this back up in a way that does not involve the switch but I'm not an electrician and haven't thought this through yet, let alone met with the electricians to discuss it. I had a terrific experience with them in installing the above described subsystem-- mainly commercial contractors, they really knew their stuff. I haven't focused on this yet, but if anybody has any thoughts, I'd certainly welcome them. Sorry to piggy back on your thread, @deadlift .
If all you do is add a transfer box, essentially nothing more than a box with some switches, one switch per circuit you want to be able to transfer, then no problem. That is what I did. When power cuts out I start up the generator, plug it in and use the transfer box switches to power the few circuits I want to keep running.  

This works great, no impact on SQ, but is manual and limited. The whole thing could be automated for a lot more money and still have no impact on SQ. 

But the reason for the lack of SQ impact is the whole thing is out of the circuit other than when in use. The minute you do anything that is in the circuit- ie connected- then it will degrade SQ no matter what. You might not hear it. From what I can tell a lot of people won't. Or you can imagine and exaggerate, like Fremer. 

Yes folks even Fremer can't get it right. One more example why of all the mountains of bull in audio none even comes close to the Himalayan Range of BS around AC. 
I have a whole house Koehler generator that I had installed when we built our house four years ago. I cannot comment on on the transfer switch as my stereo room was the last major indoor project I did after occupying the house. Since moving in  we have unfortunately had numerous outages with the longest being 6 days. I have tried playing music with the generator running and even though I get a spot on 120V there is a constant annoying low level hum like a bee coming out of each speaker so I don’t play music on my system during outages. 
I have been following M. Fremer's problem in Stereophile closely as well.   As I mentioned before in other posts, I am Director of Engineering at a green energy company and we bought that exact same transfer switch to reverse engineer.   As you might guess, his problem certainly hit close to home.

One possible problem is the ATS isn't "just a switch".  The problem with any ATS is UL108 which applies to all ATS units.   There is no relay company on the planet that can make a relay meet the requirements of UL108, rather it is left up to the manufacturer of the ATS to build enough logic and microprocessor power around a solid relay to handle the requirements.   That stuff is running full time, so expect it to bleed EMI into the lines and into your gear.   

A solid EMI brick wall filter or power regeneration system like the PS Audio one that M. Fremer installed would do the job.   The fact is, the power lines and house wiring make excellent EMI antennas, so expect some EMI to bleed into your system, and cause some havoc at some level.   

There are only two ways to eliminate the ATS and still be code compliant.   One is a manual switch, which you have to operate yourself.   The other is an ATS that has a five+ minute lag between grid failure and switch over to generator power.   That is a long time to be in the dark!  

M. Fremer also mentioned in the latest issue of Stereophile that he had a "flat topped" waveform, I assume he meant he has a clipped sine wave, for AC power.   If that is the case, he really has some serious problems there that go beyond the ATS.   
We have a customer that has the top level of his 60 Hz power waveform clipped at the transformer at the street.  His power company won't replace the transformer, since he is the only one who complained about the noise in his high end audio system.   For him, running off the solar, batteries, and inverter was the best solution.  
A manual switch will work. And all the power line and house wires are an antenna bringing EMI into the system. 

Man, that sounds so familiar. Could swear I have heard it all before somewhere. But, where? We only have one Director of Engineering around here. Who else could possibly have such advanced detailed knowledge of electricity and electrical circuits?
The last time I went through this I left gear off that needed a week to warm up.

If Fremer is seeing flat topped wave forms though, as noted above, that’s bad, and a properly installed switch should not do this.
The thing to watch for is switching transients (or switchover transients) whenever the UPS kicks in or the other way around.  Here is a good blog on the subject:

it should be possible to route this back up in a way that does not involve the switch
Yes there is. Feed the 10KVA transformer ahead of the ATS switch.

You just won’t have power to the 10KVA transformer during a utility power outage. Which you don’t want your audio equipment fed from the generator anyway.

Just tell your electrician what you want. He will know what to do.
You also might want to check out Cummins/Onan standby generators an ATS. Cost more than Generac though.


The ATS was NEVER the problem!

The problem was the quality of power he was getting from his backup generator. It was electrically noisy with fluctuating frequency and voltage. 

So he later put in a PS Audio Power Regenerator. It’s nothing more than a power inverter; it converts home power to DC, then uses an inverter to re-form the 120 vac/60 Hz supply. It prevents power fluctuations of any kind, and converts DC to  regulated, perfect true sinewave power.

Easy-peasy, simple.

No mystery here, folks.
wolfie62158 posts


The ATS was NEVER the problem!

The problem was the quality of power he was getting from his backup generator. It was electrically noisy with fluctuating frequency and voltage.
Not from his own words.
Go to time marker, around 15:40 for where he talks about the ATS, as well showing of the ATS.
ATS was in the normal power position. Generator was off.
@jea48 -thanks Jim.
The other thing I’m looking at is silencing the thing as much as possible. I’m aware of the Zombie Box, a third party silencer box with appropriate venting, but their soundproofing treatment info is a little sketchy. I’ve used melamine sheets with mass loaded vinyl as a sandwich with great success indoors. As long as the lining of the box is weatherproofed, I don’t see why that isn’t an option for this, other than expense- that stuff is pricey, at least from an acoustic supply house. More, once I get down to brass tacks with the electrician and actual ordering; I figured those Cummins things could power a hospital- I was planning on running from natural gas, assume Cummins is available that way too. Appreciate the info.
When I lived along the Hudson north of Manhattan, after Hurricane Sandy, a lot of neighbors bought whole house units. We held off only b/c we weren’t using the house all year, and started splitting time between NY and Texas. Never thought power would be an issue down here. It’s been good, quiet, relatively new infrastructure, etc. Oh well. Beats the hell out of freezing my *** off.
Best to all.
Man, that sounds so familiar. Could swear I have heard it all before somewhere. But, where? We only have one Director of Engineering around here. Who else could possibly have such advanced detailed knowledge of electricity and electrical circuits? 

Who knows?  Only some kind of Einstein could have such advanced knowledge—the kind that exists solely in your own mind!

Guys and gals, it sounds like we all need to buy some Generac stock.   Actually, if you put an Oscilloscope on the power line during switch over, it will look like a squiggly worm for a couple of minutes, then it steadies out.  So, your primary problem is soon over, however such switches were not designed with hi purity in mind.  They were designed to transfer over from a failed house feed to their generator in order to keep your lights and HVAC on.  Your electrical power company supplies you a near infinite buss.  Your  house generator does not. Your generator company can do better, but you probably would not want to pay for it.
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I have nothing against the guy (Fremer) in fact I find him funny at times, but I was thinking along the lines as audio2design mentioned that could this be a plug for a rather expensive piece of gear?

Perhaps the careful placement of mpingo discs would solve the problem?

I've been reading MF for decades. Wrote the guy a question back when he was at Stereophile, back in the days when you would fax. The man actually called me back, helped me choose my first turntable. He came up with the idea of using digital files to allow audiophiles to hear what some of these ultra-expensive cartridges sound like. The man is as far as I can tell first and foremost a serious listener and audiophile who loves vinyl.  

That said, the story as I know it is he made a good living as a surgeon but really loved audio and so as things evolved along he was able to transition to full-time reviewer/audiophile. Something I can totally relate to, believe you me! 

But life is messy, and complicated, and you'd have to be pretty low to knock a guy for being so determined to have great sound he is willing to do it in his basement- and then has the humility to show people around, put it on video, for the sole purpose of helping others with the same affliction find their way. Again, to knock a guy like that, what a total lowlife.
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... the story as I know it is he made a good living as a surgeon but really loved audio and so as things evolved along he was able to transition to full-time reviewer/audiophile.
That's quite a story, but it's fiction. Here's Fremer's background in his own words.
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... the story as "I" know it is that he made a good living selling sturgeon but really loved audio and so as things evolved along he was able to transition to full-time reviewer/audiophile.

I heard Mike was a stellar surgeon but quit to sell stereo gear.
Love his attitude. Bit of a smart ass as I am. 

I will ask a question not completely on point but one I have been
asking for 2 years now and have yet to have an answer.

Which piece of equipment does one use to measure his AC power
"Cleanliness" for lack of a better term?

What measurement is considered good? 

I would rather spend $5k on other pieces vs a regenerator
so how to establish a base line? Is this a logical question?
I fully admit to being techno challenged.

Or Should I go to ASR with this one?

Thanks in advance to anyone with a correct answer!!!
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I have a manual transfer switch and a Honda generator. I have a dedicated line for my system, but it doesn't run through the switch. I added another grounding rod which may have quieted things down a little. Electrical components should be robust. There's a big difference between a 79 cent plug and a 5 dollar one. Some panels have thicker bus bars with more copper. About once a year, I tighten all the breakers in my panel. 
I would never run any delicate and or expensive Electronics on generator power!!!!
I am an audiophile who sells and installs generators.  absolutely no reason that an ATF should impact anything.  it is closed contact.  electricity travels through it just like your main breaker.  
It is possible the main transformer down his street shorted a winding about the time of the installation and that is the reason he is having sound quality problems.   There isn't anything in the ATS that can clip a 120VAC sine wave but if he really has a clipped sine wave, it would have to be the transformer at fault.   He wasn't running from the generator at the time, so that is not the problem.

Or, as I said before, it could just be all the EMI in the ATS is flowing into his system.....
I’ve been reading Fremer’s articles with interest (and horror). It seems like an audiophile’s worst nightmare.

I had a 20 KW Generac whole house generator (propane-fired) + ATS installed ~12 years ago. I was running a lot of billing through my home office, also had multiple deadlines per day (freelance medical writer), so I couldn’t afford the usual 2 hrs to 2 days outages we get here in the winter. The generator auto-starts once a week to exercise the rotor (but is not inline powering anything at that time). Other than that, it operates flawlessly during occasional outages (we ran on generator as long as 48 hours once...2 hrs just last month).

I had then, and still have a fairly complicated desktop audio system and have used it during occasional outages when running on generator. I have not noticed anything remotely like what Fremer reports (then again, my gear is not on the level of his system). Perhaps I notice no difference because I've always run most of the electronics off a 1500 VA UPS on the desktop Just conjecture, though--I simply don’t know.
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