Please help with Spectron Musician Issue.

I haven't been on Audiogon in a while, but I now find myself at wit's end. I'd like to know if anyone can guess the problem, and where I might get it fixed... other than Spectron! (Read on.) I'm not very technical w/stereo equipment.

System: Spectron Musician II Class D amplifier, upgraded to the "Hybrid" version. Audio Horizons tube pre-amp. Resolution Opus 21 CD source. PS500 power conditioner. Magnapan 2.2R speakers. Good quality cables all 'round.

The short story:

The Left channel on my Spectron Musician II Hybrid amplifier drops out frequently. When it does, volume through the speaker goes way down, with an astounding amount of distortion. Just low-volume crackles and a disgusting trickle of music coming through. Sounds like a kazoo. In this condition, it's not likely to 'fix' itself. Other times, from startup, things sound great, but lately, it's been all bad.

I can often 'fix' the problem by disconnecting the right speaker cable (amp off, of course) so that I can hear the Left channel, starting the amp back up, and pushing the volume up quite high... almost to dangerous levels for the speaker. Most times, the channel will suddenly and sharply clear up -- I have to be ready on that volume knob! It's almost like pushing a clog through a drain. From there, the system might play fine for hours... or not. The left channel can drop out at any time, and lately, we haven't been able to get through a session without a problem.

I have eliminated ALL possible other components. Swapped speaker cables; went direct source to amp bypassing the pre-amp; tried different sources; tried RCA instead of XLR inputs. When the problem happens, it happens in the left channel of the amp despite any changes outside the amp.

Any ideas what the cause might be?

Now, here's where it gets really rich:

This amp has a history, and I know that by posting this note, I'll never be able to resell it. It has been back and forth to Spectron several times, perhaps four. One time, when John from Spectron was trying to debug an issue over the phone, he had me plug it in and fire it up, fire being the operative term. Something shorted out, smoke came up, little bit of flame. Quite spectacular.

It went out to California, and they pushed me to get an upgrade to the Hybrid version, well over $1,000 layout. I was pretty happy with the upgrade until just a few days after the warranty ran out, when the left channel issue came up.

Out to California again.Spectron said they'd honor the warranty. Spectron kept it for several weeks, and said they couldn't find any problems. Sounded normal to them, and they said they burned it for quite a while. (As I said earlier, it might play well for a while, and the problem is unpredictable.) They claim to have diddled one small, insignificant thing and sent it back.

Now they want to see the amp again (another couple of hundred in shipping costs), and yet their engineer can't even speculate what the issue might be. Clearly, I have little confidence that they'll fix the problem, and if I know Spectron, they'll try to cheap me out of more dollars. And yet, if I don't lay out more money, I have a boat anchor. Replacing the amp is not an option, financially speaking. Heck, Spectron makes the things, they should be able to repair them!

My questions:

Would you send the amp back to Spectron, given the circumstances?

If you did, would you have them honor the warranty on the upgrade, even though it has expired. I let them know about the issue BEFORE warranty expiration, but it cleared and I couldn't test it completely until AFTER warranty.

Do you have any idea what the problem might be?

Do you know of any wiz-kid repair person who does Class D work who would be a good alternative to a Spectron repair?

I've loved my amp... when it works. But this... this... is intolerable.

Thank you for your time and advice.

Rob Hanson
cold solder joint.
Somewhere is a loose something.
It is one of those 'problems from Hell'
Which is best solved by replacing the entire channel.
If they are any kind of company, that is what they should be doing.
As is, they are trying to do it on the cheap. they SHOULD just MAN UP and replace the whole channel. keep your old one for the techie boys to play with.
They should just replace the unit !!!!! When I had a problem with a new Audio Research Corp. amp that resurfaced after 1 trip to the repair tech they replaced the amp very fast without any hassle !!!!
Samhar and Elizabeth --

Thank you for your responses. They are very comforting.

I guess I have another question, then: Given the situation, how do I go about convincing them to replace the channel or the entire unit? What leverage do I have?

I should add that I bought this amp second-hand from what I thought was a reputable source. Yet, Spectron sold me on the upgrade, which was pretty much a complete replacement of most internal parts. They even bragged something like, "It's like getting 2/3rds of the amp replaced."

Thanks again for your responses. It was just what I was hoping for.

A bit of a bump on this, as I'm calling Spectron today.

Can anyone recommend a good, independent tech who might want a go at this problem? Thanks.
If Spectron can't fix it, I would doubt anyone else can. Sad to say, this may be one of the times to just cut your losses and move on. This has happened to me twice in my life - first was with a guy who does modifications. Sunk about $1K + expensive shipping into a 1K amp and the thing just sucked. Plus, it went back at least twice - once for a ground hum and once to do a few more things that he told me would work. Finally, I just sold it to the guy who did the mods for $500, as I didn't think he wanted this unit floating around with his name on it. The second time, I brought my new Mercedes to a guy who claimed to fix bumper dings without replacing the entire bumper. The owner let some dumb kid with no experience work on the car and, not only did he do a crappy job on the bumper, he got horrible overspray all over the car. The owner said his "detailer" could remove the overspray, but I decided it was better to spend the money with a more reputable person. I understand that you have much more invested than I did in either and I would ask Spectron to replace the entire channel - But if they don't and the thing still doesn't work, sometimes you just have to walk away. No, it's not right, but throwing more money into this thing is also not right. You could take legal action, but that could cost more than the whole thing is worth. Too bad you don't live near Spectron as you could take them to Small Claims Court yourself. In NY, you can recover up to 5K, which is not bad, considering you don't need a lawyer. Best of luck and I hope this works out for you.
I'm a bit surprised that you've had problems with Spectron, as far as I know they've had a pretty good reputation for customer service. At this point in time, if Spectron wants to maintain that reputation, I suggest they fix this thing free of charge and that includes free shipping both ways
I like the way you think, Unsound! Last time, it was $100 to ship one-way, and it wasn't fixed.

Thanks for your reply, Chayro. Unfortunately, I can't just walk away. There is simply no room in my budget to replace this, so if I can't get a fix, I'll either go without music, or have to sell the rest of my system.
Rob, I considered Spectron Musician as an upgrade to my class D Rowland 102 - not anymore. Rowland wouldn't do that to me. It is possible that with different speakers (complex load) it behaves differently but no matter what - when they cannot find anything wrong they should replace an amp (similar used) or at least PC boards. Do they think that you're making it up, just to send it to them and pay $100. Company I work for replaces electronics just in case when they cannot find intermittent problem. Often it is customer's fault but we exist because of customers and don't want to take risk of loosing one.
Don't walk away from the system. There are many very decent amps in the under 1K range you can use till you save up for something else. While I was in between good amps, I used an Onkyo 9555 (I think) and a Bada integrated and found them both very listenable. Hopefully, you'll get this sorted out with Spectron - I know this is a lousy solution, but perhaps you should ask Spectron to give you a "parts cost" price on a new replacement channel or perhaps a new amp. Frankly, I'm surprised as everything I've heard about Spectron, including the sound, has been extremely positive.
In defense of Spectron.....I found them to be one of of the most "product support" companies i have encountered.I had one failed part on an amplifier and dropped it off for repair and it was fixed,and completely checked out in two days.Problems with the "Musician" are few,i was told,but these are electronic devices and things can fail.
The most frustrating,and hard to repair malfunction is one that is intermittent and may seem resolved to the tech,but upon return of the unit can prove unresolved.I had one amp that had a feedback issue (yes,intermittent) and the designer of the amp literally took it apart and put it back together to resolve the issue.That was his level of frustration with the malfunction.I don't think we can expect everyone to delve this deeply into a solution. Rest assured readers that the Spectron tech has done all that is possible to remedy the situation.I have sold my Spectron,but would not hesitate an instance to buy another one if i changed speakers again.It is an amazing amplifier.Customer support was excellent.
Jazzcourier - I understand what you're saying, but given the circumstances I've encountered, my experiences are different from yours. Specifically, I sent this amp to them with the same problem in 2011, and they sent it back un-fixed.

As an update: Yes, my experience with them has been decent in terms of responsiveness, but considering that my negative encounters with the amp since 2008 have been ongoing, it's time to fix it once and for all.

I have now arranged to return the amp to Spectron, and they will honor the original upgrade warranty (2008), as I reported the problem to them prior to warranty expiration. At issue now is whether they'll pay outbound shipping, and I suspect they will. Both Spectron and I hope that we'll never have to deal with this issue again.

I'll be offline for several weeks, but will update this thread when the issue is resolved, so that people get the proper impression of Spectron service and engineering. Fair's fair, after all. I have issues with their amp -- and have had for some time -- but my hope is that the company will fully stand behind their product.
Rhanson739, I had a Benchmark DAC1 with PCX XLR mod (highly recommended) and the left channel had a intermittened issue similar to yours ... sound would fade in and out. I returned the DAC to PCX and it took the tech 6 to 8 hours of continous playing before reproducing the problem and identify the defective part. It's possible to fix but requires a competent tech. BTW, PCX was GREAT.

After paying for the mod, 2nd owner should not be an issue. Best of luck and I hope if they can't fix it, they will replace it with a new one.
Thanks, Knghifi.

Spectron was *highly* responsive to this situation, and I've had a good email exhange with the folks there, and a couple of really nice phone conversations with Toni. I can safely say that they understand how frustrating this situation is, and that they will work through it to see a good conclusion.

For the record: I've never had a problem with most of the people at Spectron; I've had continuing but varied problems with this particular *amplifier.* And this is only the second time it has been returned since becoming a "Hybrid". Prior to that, the amp had other problems unrelated to the current issue, which were satisfactorily resolved by Spectron.

In this situation, the issue of money never even came up. Spectron will provide a solution under the Hybrid warranty, and has graciously agreed to pay shipping BOTH ways, which is a huge help for this cash-strapped guy.

When I first wrote my post, I was asking the general audience a) for a possible theory on what might be wrong, and b) for an idea of how I might address the issue with the manufacturer. Some may have interpreted that I was casting apersions on Spectron (and I actually would redact one statement I made in the original post, if I only could), but I was more at "wit's end," complete with tones of frustration. That was before I talked to them. I feel better now. :)

I believe that Spectron, and Manh in particular, have stepped up to the plate in fine fashion, and I'm confident that I'll have a good solution when all is said and done. As promised, I'll provide a further update in about a month.

Thanks also to everyone who chimed in with their thoughts. It really helped to inform my dealings with Spectron, and for that, I'm grateful.

Expensive things sometimes need support and TLC, and all things stereo are close to our hearts. At a time like this, it's good to know that a quality manufacturer will step up, "do the right thing", and maintain a solid reputation in the industry. I love to do business with companies like that.

Thanks again, all,
Thanks for the follow up. It's appreciated. I wish you the best of luck, and kudos to Spectron for stepping up and doing the right thing!
The above is the main reason I would never own a Class D amp: I will never own that which I could not repair myself, and I have 32 years electronics repair experience! Switching power supplies/amp circuits do not follow normal Ohms Law Theory, and therefore I must avoid. Former US service engineer for dCS and Nagra, also certified McIntosh Labs, Musical Fidelity, Plinius and Eastern Electric, therefore Analog/Digital/Tube/Solid State no problem but NO Class D for meeee.
Mcintech, It is not that difficult to fix it if you understand its operation. It is pretty much modulator chip + output Mosfets. If Mosfets are not driven then replace chip otherwise find bad Mosfet. I'm not sure why "it doesn't follow ohm's law" but if you don't like it then perhaps you don't use SACD (class D) or Sigma-Delta DACs (class D).
In spite of common believe, originated at noisy computer supplies, well designed switcher is quieter than linear supply and that's why Rowland uses them not only in the latest model 625 amp (class AB) but also in Capri preamp - where efficiency is secondary thing. Linear power supplies are also switchers of sort, that produce high frequency noise and 120Hz ripple difficult to remove. Rectifier diodes are switching at max voltage while good SMPS switches at zero voltage/ zero current. Linear supplies don't have line or load regulation (not to mention over-current protection) and require 10x larger power transformers and a lot of electrolytic caps to bring down 120Hz ripple. They are unprotected, unregulated, inefficient, noisy, large and clumsy - a Dinosaurs.
Mcintech -

Thanks for putting this into perspective for me.

You see, I never had any of the jobs you mentioned, nor do I have 32 years electronics repairs experience. Heck, I probably couldn't recite Ohms Law Theory on a bet. Clearly, then, I can't repair an amp of any type by myself. While your record is something you can be proud of -- and I'm sure you are -- it must also be a burden.

See?... I can own any darned amp I want to own, Class D, or otherwise. They're all the same to me, except for the sound quality.

Rhanson739, I like your approach. I tend to over-analyze while at the end it comes to sound quality alone.
I am curious to what the outcome is. I have the same problem recently. I thought it was my preamp, speaker cable, source and now I believe it is my Spectron Musician II that has been upgraded. My problem is the right channel plays great even for hours and then drops out so low you can barely hear it.

Please let me know what the outcome is as I will be contact Spectron next week.

Sorry, I meant the left channel same as your problem. It plays well and then the left channel goes completely out except for very faint music. Please keep me posted. I wonder if there are others with this same problem.

Revrob -- I've replied to your private message. Sorry for the delay, I've been offline for a month.

Sadly, the amp never made it to Spectron for repair. No one at Spectron had informed me that they moved locations two years ago, so I sent it to the wrong address. You'd think that UPS could redirect the package to the new address, as they had Spectron's account number at hand.

So instead of having it fixed while I was gone, I now have to resend it and wait until it's fixed... without music. Sucks.

It was a careless slip-up on both our parts, I'm sure, but still... Grrrrrrrr....
Revrob --

Does your amp issue sound something like this?

YouTube video of my Spectron issue

** Update **

I'm pleased to report that this issue has been resolved by Spectron.

After the amp was returned by UPS due to an obsolete Spectron address, I sent it back in on Oct. 22nd. It was returned on Nov. 19th.

The lead engineer told me: "I suspected and replaced a new Modulator on the amp module (Left) and also replaced the new Regulator boards (I do not think it is a problem) to be safe."

Seems to me that he wanted to be extra-special careful about the repair, and then he tested it for quite a while -- likely also helping to burn in the new parts.

The amp is back home now, and is sounding great. After so much time chasing down this problem, I still seem to be in the chronic habit of checking the Left channel, but I'm sure that'll pass.

I'd like to congratulate Spectron for following up on this issue and making me a happy customer.

Kudos to Spectron for stepping up and doing the right thing.
Congrats Rob and thanks for sharing your experience.
It's the most complex audio amp on planet Earth.
I haven't been on Audiogon for a few years. I've had this exact issue with my Musician II Hybrid. I shipped it to Spectron twice and they said the amp worked perfectly and they didn't have issues with one of the channels dropping off. I'm going to check back with them and see if they will now admit to the issue and see if they will repair my Musician II. I'll report back on what happens.
I too have had the same problem with my Spectron Musician 3 MK2. Over the years the left or right channel has either faded out or stopped working altogether. Right now the left channel is noticeably quieter than the right and it was just "fixed" 2 months ago. I have checked everything and its definitely the amp. At this point I have shipped my amp from New York to California 5 times over they years (most recently in November 2013). Each time they fixed and returned it promptly, courteously, and free of charge.

In Spectron's defense they have always responded each time and offered to fix the problem. But that doesn't change the fact that the problem persists after shipping the amp across the country 5 times plus the hours of silent disappointment and time spent tinkering and trying to diagnose the source of the cause (ie. components, cables, tubes, fuses, speaker drivers etc.)

When this amp is working it is fantastic. Its sound is powerful, natural, and dead quiet. I have even considered buying another and bi-amping them but the unreliability has given me me serious doubts.
I own a pair of Spectron III MK2 monoblocks. I have had them for I think over 4 years without problems. I am curious since you have had both the left and right channel go out what turned out to be the problem with the amp? I am curious since I am a Spectron owner.
Looks like it's time for me to update my own thread!

After receiving my amp back from Spectron, I continued to have some problems. Time to throw in the towel, I thought. The people at Spectron and I worked out an arrangement, and as a result, I'm now running a Spectron Musician III MK2 with all upgrades.

In a word, "happy." I haven't had a single issue with the new amp. Nada... Zilch... Perfect operation. It sounds fantastic.

My only "problem" is that getting the new amp caused a slew of upgrades, to the point that every component is new, from speakers to cables. Having just added some Vandersteen 2wq subs into the mix, I really couldn't be more delighted with how things turned out.

I'll probably never deal with this type of issue again. Just too much angst and expense in that.

Just a word of warning. Now that you have a Musician III Mk2, if you try a second one and run them in balanced monoblock mode, you would be amazed how much better they sound and won't be able to go back to one amp in Stereo mode.

When you run them as monoblocks, you just have to switch the output phase switch on one channel of each amp and connect the speaker cable to each channel's top binding post. This way each channel drives each phase of the output with common mode noise rejection.

You also get double the slew rate, much wider bandwidth, and more powerful, controlled bass. Also of course you get tremendous power with peaks to 2 kilowatts possible.

A final suggestion, the Spectrons benefit from being left on 24/7. They take days or weeks to reach their full potential. They also benefit from the best power cords to get the best slam, bass extension, and clarity.
Thanks, Kernelbob... I think... :)

Budgetary restrictions preclude the possibility of a second Musician III at this time, although I do appreciate your insights.

One thing that surprised me: The Vandersteen 2wq subwoofers were the best possible additions (given my budget, of course.) With the battery-biased crossovers between the pre- and amp, they take a lot of the load off the Spectron, leaving it more free to handle the power-hungry Magnepan 3.7s, as well as providing bass that the Maggies can't really reach anyway. The difference was anything but subtle... we haven't turned off the music since getting the subs in.
Kudos to Spectron for their help, but considering their reliability, I wouldn't own one for anything.
In all fairness that was an older design. I had a Musician III for many years with no problems. It was one of the best Class D amps out there.
I been using the latest model Spectrons as monoblocks for the last 5 years. I initially had a problem with hum from one channel. I sent it back to Specton and they fixed it, no problem. Then last year one of the amps wouldn't switch on. I returned it to Spectron for a rush repair, and had it back from Spectron in 3 days (I paid for FedEx) in perfect working order. Both repairs were fully covered under the warranty.
Its true that these are complex amps and may require occasional servicing. But Spectron takes good care of its customers, and the performance of these amps more than compensates for the occasional service issue.
Hi Snopro,
It seems like you've run the gamut of amplifiers, from the high power class D Spectron Musician to your current 8 watt SET 300b. That's quite an interesting contrast.
Yeah Charles, I use to run Salk HT-3, which needed a lot of power. The pairing was very nice, just missing that SET magic!

Sorry for going of topic.
Going off topic by mentioning SET is never a problem with me:)
I've been using Spectron monoblocks for 5 years. I've had two servicing issues during that time that required sending back a single amp. Both times the amps were quickly returned to me in perfect working order. I only paid for shipping the amps to Spectron. I've been completely satisfied with Spectron's customer service, and their current amps sound fantastic.