[nurxhunter]

"Singlepower was a train wreck of company, and their amps all have to be checked out to be safe, but I think it does a disservice to say that they all have to be completely gutted"

A disservice to whom? Not those who profit from the situation, and not those with grudges, albeit justified. This thread has all types posting.

Thanks for pointing out with such class that the thread may be getting a little extreme again.

Here is what we know, summarizing the posts so far; and if any of this is wrong, please point to the source of the information

-The transformers on all stock Extremes or all SinglePower Extremes appear to require replacement. This is not horribly expensive ($175-$300, installed depending on the transformer and hourly labor cost).

-Some other parts may, or may not, need replacing. This depends on individual cases. When there is a problem, it has been visible to the naked eye, usually, and is a straightforward fix--typically, for a competent tech. This is known, simply, as a part failure, which happens in the finest gear.

--The upgraded transformers may improve the sound some. It is not dramatic. Other parts (except in failure) cannot really be expected to improve the sound, because they are already of pretty high quality on Stock Extremes.

--More likely, you can refine the sound of a stock Extreme to your own personal preference by tube rolling or cable swapping than by giving a tech a blank check.

-You can spend $1,200 (or more) building a new DIY amp into the Extreme shell; or, you can spend around $200 repairing a true Extreme, and taking it home as a true Extreme, and enjoying it with new confidence, after certified by any tech who does this for a living--they are not hard to find--a list of such techs has been posted.

-The majority of issues appear to be with customized Extremes, especially on MPX3 boards.

--The issues with true STOCK Extremes have for the most part been more minor: (a) the tranny ($70-$150 part cost) b) a resistor for a few pennies a part; c) possibly a cap.

-If an Extreme becomes highly modified, such that new circuitry is added, and not simply new components swapped, then it is no longer an Extreme, by definition. No one knows what is is --other than it becomes another DIY with its own set of UNKNOWN risks, as for any DIY. At least the SP issues are now well known.

-All SinglePower products got universally glowing reviews everywhere for a very long time. It is hard to find a negative review of the sound for stock amps, if such reviews exist.

-If Modified Extremes sound better than the original, then a new rating system is needed, because the original achieved the highest reviews possible sound-wise, everywhere, from everyone.

--As SinglePower was going under, the owner left a lot of people hanging, as usually happens when an enterprise goes under. Some of those who lost money, or have friends who did, are not big fans of the name. You can find them in this thread, and in the other 'explosive' thread.

--These threads have provided a service to guide members to the core issues, which I have tried to enumerate above for the SinglePower Extreme, as fairly as I could, given the disclosure that I remain a big fan of SinglePower designs, but I regret that some lost money or endured hassle with an enterprise that its owner could not effectively maintain. Everyone would be better off if MR got investors when the time was right, or at least hired a business manager. Old story, for centuries, probably.

 

[spritzer]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif I'm not sure that is really accurate. My SP Extreme needed a new trafo, and a pair of new resisters. That is all. Sounds better than it did before, and is perfectly safe. Singlepower was a train wreck of company, and their amps all have to be checked out to be safe, but I think it does a disservice to say that they all have to be completely gutted - many can likely be saved with a less costly approach. I think it's important for current SP owners to understand that.

You can put a bandaid on it and hope for the best or just do the job properly in the first place. Making an amp safe and have it run at 100% are two very different things. Most of the parts used are dirt cheap and since everything SP was either run on the line or far out of spec you can never know if said components are on the brink of failure. The tube sockets are oxidized to hell and back and all switches in the circuitry are downright dangerous so scrapping it all would be would be the best course of action.

Granted, what I'm dealing with is worse then most of the other amps but the bottom line is what you want to end up with. The only things that could have been saved in my amp are the plate resistors for the third stage but they are dirt cheap Dale WW and not non-inductive so I'd rather just get rid of them. I may use some of the wiring for the filaments more as a symbolic gesture then anything else but the rest is just trash.

 

[nurxhunter]

Does not look like dirt to me.

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Note: This is before I had the satellite toroidal plate voltage transformer put in and had the filament transformer properly wired. If anyone sees variances, please let me know. Several other of us lay headphiles have posted pics of the same Rev 2007. I recall seeing a later RevB200* board that looked even more elegant. We have seen, as I recall, an Stock Extreme missing one of the Dale resistors. Possibly a failed cap. on one Stock Extreme. That's it to my recollection.

It's a shame that (around 2% by what I can estimate) of the folks out there got boat anchors and not the amps they expected; but, from much of the posts and reviews over seven years that SP was selling, it seems the variances (except for underpowered transformer in Extreme) in[size=medium] stock standard amps [/size]are relatively few.

[size=medium]That modified amps seem to have most of the problems suggests that when a circuit is 'juiced' and not given time for debugging, or not objectively measured and properly scoped, then the possibility that the upgrade does more harm than good is quite real[/size].

 

[spritzer]

I said trash as it belongs in the trash since we can't be sure what abuse the components have suffered through. You don not want those output caps to do break down and since they are often overloaded, it's more then possible.

That amp has max 200$ in parts with inductive Dale WW resistors, RN60's and basic quality Nichicons. Fairly basic SP stuff but I really like the utterly bonkers way of mounting the RCA inputs. Mikhail must have not known anything about proper grounding in a circuit...

Even basic amps are fubar but the upgrades were often just ways to cheat more money out of the punters so low voltage rated switches used to switch high voltage etc or he just didn't install anything.

 

[nurxhunter]

is what this is.

 

[Bolder]

Quote:

-The transformers on all stock Extremes or all SinglePower Extremes appear to require replacement. This is not horribly expensive ($175-$300, installed depending on the transformer and hourly labor cost).

The first part of this statement is absolutely true. The transformers on all Extremes should be replaced for safety reasons and to make sure the amps work correctly. The transformer that was installed at the factory on the amp I rebuilt was the Plitron toroidal. Part of the dual primary winding was used for the high voltage section. This not only is unsafe, it pulls current from the secondary section. In this particular case, the filament voltage was running at only 4 volts. This was from the factory.

In order to replace the transformer the entire circuit board needs to be removed and each tube socket unsoldered from the board. This is documented in the first post in this thread. Depending on one's skill this can easily take 3 + hours to accomplish. It also makes things rather difficult to troubleshoot if there may be other problems.

I made the rebuilt unit in sections so if any problems come up in the future, all sections of the amp may be easily accessed without complete disassembly.

Quote:

-Some other parts may, or may not, need replacing. This depends on individual cases. When there is a problem, it has been visible to the naked eye, usually, and is a straightforward fix--typically, for a competent tech. This is known, simply, as a part failure, which happens in the finest gear.

Using parts that are severely underated (such as a switch rated for 25 volts in a circuit where it sees 500 volts) is not something that happens in the finest gear. Not installing balancing resistors on caps wired in series is bad engineering and creates a safety issue should one fail, as caps do. All of the circuit board models require complete dissembly to access any part. This is not a simple, straightforward fix. It does involve many hours of work.

Quote:

Other parts (except in failure) cannot really be expected to improve the sound, because they are already of pretty high quality on Stock Extremes.

Nichicon GQ and LQ series polarized caps, along with Xicon polarized caps are not what most would consider high quality parts, especially when used as signal coupling.

Quote:

-If an Extreme becomes highly modified, such that new circuitry is added, and not simply new components swapped, then it is no longer an Extreme, by definition. No one knows what is is --other than it becomes another DIY with its own set of UNKNOWN risks, as for any DIY. At least the SP issues are now well known.

Such as a filament circuit that cannot supply 6.3 volts. Even in the models that are built with transformers that do supply the correct voltage and current, the simple C only filter has close to half a volt of AC ripple. The filament circuit I built has 0.01 volts of ripple at 6.3 volts under full load. It may or may not sound "better" but it is measurably quieter and allows the tubes to work correctly.

 

[nurxhunter]

"In order to replace the transformer the entire circuit board needs to be removed and each tube socket unsoldered from the board. This is documented in the first post in this thread. Depending on one's skill this can easily take 3 + hours to accomplish. It also makes things rather difficult to troubleshoot if there may be other problems."

This is one approach--and quite expensive. The other approach--which has been validated by others here, including me--is to simply drill two holes through the board to get to the bolts holding the transformer housing. This takes less than 30 min to do carefully. After this is accomplished, the transformer replacement becomes pro forma.

My tech, who is of the sort who ALWAYS presents options, was to suggest that a low profile torroidal transformer be placed in the case to supply the plate voltage, and to then simply and properly wire the existing transformer, assuming it shows no sign of overheating and put out the requisite 8 amps (which is a simple measurement to accomplish). The entire affair cost me around $200, and aside from the part order, took 2 days to turnaround. This solves the main problem documented with the Extreme.

I have posted the contacts of a tech that now knows the basic issues, and who really charges quite fairly, turns the work around fast (not weeks or moths as others have posted). If others are interested, please PM me. Be warned, however, if you ask him to remove this board and replace those caps, he may simply tell you that you are insane, but he will honor and comply with your wishes. I look for EE technicians who are not audiophiles when it comes to repairs. That's me.
************************************************** *******
If you are saying----in your opinion, and your opinion of others' opinions, whose opinions represent the majority of opinion on audio opinions--that the caps MUST be replaced to acheive a resonable and customary standard throughout the field, and that this WILL result in superior sound--then--I must ask, with respect:


Are you a hobbyist, or an owner of any IRS-registered enterprise. What I mean is are you really a Junior Headfier or more of a Trade Member? If the latter, should that be in your signature when you post on threads? I am a junior, and not so versed in forum rules.

In my domain, when publishing opinions, disclosure of conflicting affiliation or self-interest relationship is required. Maybe this is not the case here? I will say, with some hesitation, that the nature of this recurring thread truly has me wondering on objectivity, and whether the best interests of the members are really being served at this stage?? At first, it was mostly technical and informative.

Thanks

 

[HeadphoneAddict]

Quote:

Originally Posted by nurxhunter /img/forum/go_quote.gif "In order to replace the transformer the entire circuit board needs to be removed and each tube socket unsoldered from the board. This is documented in the first post in this thread. Depending on one's skill this can easily take 3 + hours to accomplish. It also makes things rather difficult to troubleshoot if there may be other problems." This is one approach--and quite expensive. The other approach--which has been validated by others here, including me--is to simply drill two holes through the board to get to the bolts holding the transformer housing. This takes less than 30 min to do carefully. After this is accomplished, the transformer replacement becomes pro forma. My tech, who is of the sort who ALWAYS presents options, was to suggest that a low profile torroidal transformer be placed in the case to supply the plate voltage, and to then simply and properly wire the existing transformer, assuming it shows no sign of overheating and put out the requisite 8 amps (which is a simple measurement to accomplish). The entire affair cost me around $200, and aside from the part order, took 2 days to turnaround. This solves the main problem documented with the Extreme. I have posted the contacts of a tech that now knows the basic issues, and who really charges quite fairly, turns the work around fast (not weeks or moths as others have posted). If others are interested, please PM me. Be warned, however, if you ask him to remove this board and replace those caps, he may simply tell you that you are insane, but he will honor and comply with your wishes. I look for EE technicians who are not audiophiles when it comes to repairs. That's me. ************************************************** ******* If you are saying----in your opinion, and your opinion of others' opinions, whose opinions represent the majority of opinion on audio opinions--that the caps MUST be replaced to acheive a resonable and customary standard throughout the field, and that this WILL result in superior sound--then--I must ask, with respect: Are you a hobbyist, or an owner of any IRS-registered enterprise. What I mean is are you really a Junior Headfier or more of a Trade Member? If the latter, should that be in your signature when you post on threads? I am a junior, and not so versed in forum rules. In my domain, when publishing opinions, disclosure of conflicting affiliation or self-interest relationship is required. Maybe this is not the case here? I will say, with some hesitation, that the nature of this recurring thread truly has me wondering on objectivity, and whether the best interests of the members are really being served at this stage?? At first, it was mostly technical and informative. Thanks

Great - why don't we just go chase off anyone who is willing to rescue SP amp owners with bad amps.

 

[tagosaku]

Quote:

Originally Posted by nurxhunter /img/forum/go_quote.gif Are you a hobbyist, or an owner of any IRS-registered enterprise. What I mean is are you really a Junior Headfier or more of a Trade Member? If the latter, should that be in your signature when you post on threads? I am a junior, and not so versed in forum rules.

LOL
I guess you write better than read

 

[The Monkey]

Quote:

Originally Posted by nurxhunter Are you a hobbyist, or an owner of any IRS-registered enterprise. What I mean is are you really a Junior Headfier or more of a Trade Member? If the latter, should that be in your signature when you post on threads? I am a junior, and not so versed in forum rules.

What's an "IRS-registered enterprise"?

 

[n_maher]

Boulder is a MOT, he just hasn't had a tag applied to his name yet (not his fault).

With respect to all those participating in this thread, please, keep it civil. The situation is pretty much no fun for all those involved and sucks to a degree that defies description for those that paid good money for products in many cases that require repair from day 1.

 

[mrarroyo]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif That's the case with most SP amps. Attenuators (as long as they weren't built by SP), input and output jacks and perhaps some of the electrolytic caps are the only things you can save, the rest is just trash.

I am sorry but I can not agree, at least in the case of my MPX3 that was not the case. My needed to bleeder resistors plus the replacement of a couple of diodes for a grand total of under $25 in parts. I replaced the sockets w/ higher grade ones but they did not need to (a major wish of mine

).

For the record at the time my amp was being checked I asked if there was anything else that should be changed and I was informed nothing had to be changed unless I wanted to run 6BL7 in all three positions, if so a larger transformer would be needed. However I chose not to do so since I can run a 6BL7 as a driver and a pair of 5687 as output and not exceed the 3 amp rating of the stock transformer. Cheers.

 

[spritzer]

Again there is a difference between fixing and properly fixing. Take the ES-1 for instance, the most horrible "design" error that has to be fixed is the shared filament supply. With the amp running like this it will eat up the tubes in no time but the fix shouldn't take anybody experienced more then a couple of hours to fix. With some shuffling of parts you can even use the same umbilicals (though I'd replace the internal wires) and it costs nothing but time. The amp is now pretty much safe to use but is it running at 100%? Far, far from it actually.

With the other amps this is the same. You can fix the worst of Mikhail's mistakes easily but the amp is not running at 100%. Worse yet, you have no idea in what shape those parts are and what stresses they have suffered over the years. If the diodes have almost burnt through the PCB can you imagine what they did to all the nearby parts? Missing leveling resistors on the main reservoir caps affect other components as well.

While most of the amps will probably be just fine with a few simple mods doing the same on my ES-1 would have been utter madness. Main coupling caps were 400V but should have been 1000V, damaged caps in the PSU and resistors running on the bleeding edge.

 

[nurxhunter]

N,

UR right.
 

 

[n_maher]

Quote:

Originally Posted by nurxhunter /img/forum/go_quote.gif The data suggest to me that most stock amps are fine, most customized units MAY have issues. I did not do a thesis on this--I really have only opinion, not worth as much as certification.

I would only add that based on what I've seen and observed first hand that your assumption is incorrect and dangerous with regards to the Extreme. The "stock" Extreme, as I detailed in the first post in this thread, is far from fine. I cannot speak about other SP models directly but would again relay that the same type of misuse of transformers has appeared in other models. How do you tell if your amp is problematic, I can't help there either. I can only say that if I owned a SP amp I would have it checked by a qualified individual.