# Warning About The Singlepower Extreme - Owners Please Read



## n_maher

Disclaimer: I am not a professional. The information provided below is intended as a community service. Any work or repairs performed should be done by a professional. Any use of the information provided is at the owner's risk. The pictures and contents of this post are not to be re-used or re-printed with my consent.

 The following details my experiences after having been asked to look at a Singlepower Extreme for a fellow member here at Head-Fi. What I found is, in my opinion, a very serious problem. The amp in question appears to be one of the early Extremes and a pretty basic, stock unit. The first thing that I did was to open up the chassis and look for obvious signs of damage, there weren't any. And despite using a PPX3 pcb (evidently at some point Mikhail offered to mod existing PPX3s into Extremes) everything on the board checked out just fine. The owner had complained that the transformer smelled burnt the last time he tried to use the amp so I figured that was probably where the problem was located and set about trying to figure out how to get at the transformer without taking the entire amp apart. Mikhail made these very difficult to work on, that's for sure. 

 Here are some basic internal shots.

*Overall*






 Filament Rectifier (note the lack of thermal compound)










*Tubes sockets air-wired to PCB*





*Wires pulled so tight they are nearly cut through the casing, no grommets on any of the holes in the chassis or pcb*





 So the kicker here is that in order to get at both the fasteners that hold the transformer cover and the fasteners that hold transformer itself you have to remove the pcb. What makes the situation worse is that as you can see the tube sockets are air wired and what you can't see is that the sockets are mounted in such a fashion that in order to remove them you have to remove the pcb. So, in order to remove the pcb you have to desolder each and every connection to the 3 tube sockets. I decided that before going through all that effort that I would attempt to find a way to at least remove the transformer cover. I was able to figure out that at those two locations the pcb was basically clear enough for me to drill access holes.











 What I found when I removed the transformer cover was not pretty and was entirely unexpected.






 What you're looking at is a completely cooked transformer. What struck me as very strange is that it is *only* a filament transformer and I know that this amp doesn't only run off of 6.3V. I'll do my best to describe this and ultimately I'll draw a small schematic but for now words will have to suffice. The transformer in question is a dual primary, dual secondary transformer. The two primaries are 2x117VAC (for use in both ~115 and ~230VAC countries) and each secondary is 6.3V @ 4A. So in normal use in the US one would wire up the two primaries in parallel and each secondary would be 6.3V @ 4A. What Mikhail did was to wire *one* primary to the IEC inlet and one to the PCB. In essence this is using the second primary as a secondary (very bad) and the real problem is that by doing so he cut the secondary current capacity in half (2A vs. 4A). So now when he ran both secondaries in parallel he got a total of 6.3V @ 4A instead of the rated 8A. 

 The following is taken directly from Hammond's (the manufacturer of this transformer) FAQ on their website:



 Clearly Hammond never intended for their transformers to be used like Mikhail did and they are very clear on the consequences. 

 Now in a best case scenario this might not be a terminal problem if the amp required less than 4A on the low voltage windings but this isn't the case. Each 6AS7 on the output pulls 2.5A and the 6SN7 input can pull up to almost 1A (depending on which 6SN7ish tube the owner uses) but generally will use .6A. So in a pretty average operating case the low voltage section needs to provide at least 5.6A and has only 4A to give. What that means is the minute you turn on the amp the low voltage section is running 40% over spec, not good. No, back to the "HV" section of the trafo. There's some debate about just how bad it is to use a primary as a secondary and I'm not qualified to say for sure but you can bet that the UL and Hammond had no intention of this being done. And we've observed that what Hammond predicted has in fact happened.

 Now what is it going to take to fix it? The transformer must be replaced with a proper spec'd unit. I've seen examples that might work that range in price from ~$80 to well over $100. And that is just for the part. I'd also estimate that owner's will be looking at at least a couple hours of labor, potentially much more. More importantly what is the danger here? Well that is, in my opinion, the worst part of this. I am not able to say exactly what would happen if the transformer was able to fail completely and essentially melt itself together but in a best case it will simply pop the fuse on the IEC input of the amp and the amp will die a quiet death. In a worse (not worst, who knows what worst is) case it will run for a while and produce a ton of heat any potentially short live AC to the chassis and then maybe pop the fuse before it throws a breaker. The Extreme that I looked at did have the chassis connected to safety ground but I cannot say if that is the case for every amp Mikhail built using a transformer setup this way. But most casual owners that I know would probably try to replace the fuse if it blew and would then subject the transformer to another round of abuse and who knows what would happen there. I did run this scenario past a couple of friends that I have in the electronics business and they were amazed by just how dangerous this is for the consumer/owner. Owners should understand that some of the possible failure modes for the transformer could be lethal and I'm not in any way trying to over-state situation. 

 So my advice to any SP Extreme owner is to find out what transformer your amp uses or stop using the amp altogether. Please understand that I am not a professional, cannot look at your amp for you or offer to repair it. You will want to seek professional help since there may be other issues with your particular amp that I have not seen and therefore did not mention in this post. Sorry to be the bearer of bad news but after seeing what I did I could not simply remain silent.


----------



## Skylab

There is no joy in being a Singlepower amp owner 
	

	
	
		
		

		
		
	


	




 Nate, thanks for publishing this - it is a huge service to the community. I wish I had never bought an extreme. I tried to get mine open to take some pics, but can't get it open. Looks like I have an expensive doorstop, but better that than an unknown fire hazard. Thanks for the important information.


----------



## HeadphoneAddict

Try an impact wrench - you plug in a hex bit and tap on it with a hammer a few times, and it should loosen it up for you. Then you can look inside and correct the issues and enjoy it again. Drilling and tapping the heads might work, but you could break the screw in half.


----------



## gevorg

Maybe we need to pm a link to this thread to all users who list "Singlepower" in their profile. Or just send it to all, better be safe than sorry.


----------



## thathertz

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_There is no joy in being a Singlepower amp owner 
	

	
	
		
		

		
		
	


	




 Naten thanks for publishing this - it is a huge service to the community. I wish I had never bought an extreme. I tried to get mine open to take some pics, but can't get it open. Looks like I have an expendive doorstop, but better that than an unknown fire hazard. Thanks for the important information._

 

Skylab. LOTS of joy here!

 However, it seems we all need to get a handle on what we own individually
 and what needs to be done to make our amps safe. 

 There are some serious problems. No doubt about that. 

 But, life-threatening issues aside, alot of SP amps really 
 do sound very very good. They would not have gained
 such a reputation otherwise, and I really don't think it's a case
 of the Emperor's new clothes. 

 People need to get their amps checked by a professional
 and go from there.


----------



## Mher6

Has anyone else had problems with the Extreme's transformer? I shined a flashlight into the transformer chassis of my Extreme and the transformer looks normal (no burn marks, discoloring, or smell). Despite Mikhail's build quality problems, maybe not all Extremes are wired incorrectly?


----------



## John D.

Seeking address of West Coast Singlepower Extreme repair station.


----------



## n_maher

Quote:


  Originally Posted by *Mher6* /img/forum/go_quote.gif 
_ Despite Mikhail's build quality problems, maybe not all Extremes are wired incorrectly?_

 

Therein lies one of the major problems with trying to get a handle on how big this problem could be. I've only seen on Extreme in person and detailed pictures of another 2. All 3 have three different issues, but the other two appear minor compared with this one. 

 If you can safely access the inside of your Extreme there's a good chance that we could tell how the trafo is wired and if it's the same under-spec'd Hammond. I wouldn't trust shining a light through the trafo enclosure if it were my amp and had that little trafo box on it. You can see in the picture that Kevin Gilmore posted in the other SP thread what an Extreme with a properly spec'd trafo looks like. The transformer in that picture (a custom Electraprint) weighs more than the entire original Extreme did.


----------



## moredes

Skylab, 

 Have you tried putting a soldering iron to the screws before trying to unscrew them? Heating the screws might allow you to break them loose.


----------



## moonboy403

Thanks for the detail explaination of what went wrong with the Extreme!


----------



## Uncle Erik

Quote:


  Originally Posted by *John D.* /img/forum/go_quote.gif 
_Seeking address of West Coast Singlepower Extreme repair station. 
	

	
	
		
		

		
		
	


	


_

 

I posted this in another thread, but I recently came across this guy:

 Jeffrey Angus
 Stay Connected
 10916 South La Cienega Boulevard
 Lennox, CA
 90304-1105
 310-337-1036
Stay Connected

 I haven't visited him or seen his work. I plan to drop by and say 'hi' one of these days, but he holds himself out as a radio/TV/Hi-Fi vacuum tube repair guy. A vacuum tube TV is an order of magnitude more complex than an amp (I've restored one), so anyone who can fix a TV should have no trouble with your amp. Give him a call and report back if he'll take on these amps.


----------



## thathertz

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_Therein lies one of the major problems with trying to get a handle on how big this problem could be. I've only seen on Extreme in person and detailed pictures of another 2. All 3 have three different issues, but the other two appear minor compared with this one. 

 If you can safely access the inside of your Extreme there's a good chance that we could tell how the trafo is wired and if it's the same under-spec'd Hammond. I wouldn't trust shining a light through the trafo enclosure if it were my amp and had that little trafo box on it. You can see in the picture that Kevin Gilmore posted in the other SP thread what an Extreme with a properly spec'd trafo looks like. The transformer in that picture (a custom Electraprint) weighs more than the entire original Extreme did._

 

Nate, I posted this in the 'Supra grenade' thread but it's still relevant here. 

 The transformer on my early p2p MPX3 runs really hot. 
 Too hot to touch in fact. 
 Problem?


----------



## Happy Camper

Has anyone tried taking the can off a Plitron? 

 Did SP have builders at one time? Perhaps he sucks at building and when he took over the gig, things went to sh!t. 

 This man just keeps on giving.

 Not to speak for Nate but, yes a hot tranny is a problem. Time for a service visit.


----------



## thathertz

Quote:


  Originally Posted by *Happy Camper* /img/forum/go_quote.gif 
_ 
 This man just keeps on giving._

 

Made me laugh big time. 

 Apparently it was just Mikhail and one other 'builder'.


----------



## n_maher

Quote:


  Originally Posted by *thathertz* /img/forum/go_quote.gif 
_Nate, I posted this in the 'Supra grenade' thread but it's still relevant here. 

 The transformer on my early p2p MPX3 runs really hot. 
 Too hot to touch in fact. 
 Problem?_

 

It's tough to say really, but I definitely find it cause for concern. I've rarely come across transformers that were designed to run that hot and never in a commercial product. In order to tell if it's really a problem in your case we'd need a lot more information. E-diagnosis of some of this stuff is difficult if not impossible. I'll defer to Dr. Gilmore on this one.


----------



## thathertz

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_It's tough to say really, but I definitely find it cause for concern. I've rarely come across transformers that were designed to run that hot and never in a commercial product. In order to tell if it's really a problem in your case we'd need a lot more information. E-diagnosis of some of this stuff is difficult if not impossible. I'll defer to Dr. Gilmore on this one._

 

Thanks for taking the time Nate. 

 Apparently (after some detective work) my MPX3 is an early
 (probably 2004) P2P model. It had two previous owners before me.
 No issues have been reported by those owners and I trust their word.

 I need to get the amp inspected by a competent technician. 
 Not an easy prospect here in the UK but I've found several 
 candidates that are looking good. 

 I'll update the relevant threads here when I have some info. 

 Cheers Nate


----------



## moonboy403

Quote:


  Originally Posted by *thathertz* /img/forum/go_quote.gif 
_Thanks for taking the time Nate. 

 Apparently (after some detective work) my MPX3 is an early
 (probably 2004) P2P model. It had two previous owners before me.
*No issues have been reported by those owners and I trust their word*.

 I need to get the amp inspected by a competent technician. 
 Not an easy prospect here in the UK but I've found several 
 candidates that are looking good. 

 I'll update the relevant threads here when I have some info. 

 Cheers Nate_

 

I just wanna say that it doesn't mean anything really. An amp can fail at any given moment. My Extreme was issue free through two previous owners, but it crapped out on me one day.


----------



## DavidMahler

Quote:


  Originally Posted by *thathertz* /img/forum/go_quote.gif 
_Skylab. LOTS of joy here!

 However, it seems we all need to get a handle on what we own individually
 and what needs to be done to make our amps safe. 

 There are some serious problems. No doubt about that. 

 But, life-threatening issues aside, alot of SP amps really 
 do sound very very good. They would not have gained
 such a reputation otherwise, and I really don't think it's a case
 of the Emperor's new clothes. 

 People need to get their amps checked by a professional
 and go from there._

 

NO..... People need to GET THEIR AMPS period..........don't endorse this piece of **** company in any way any longer..... I can't stand it.......Single Power is a FRAUD company.

 EDIT: My anger is not directed at you sorry, but I am just so sick of all these Single Power threads. Mikhail Rotenberg stole thousands from me, and left me with no amp and damaged other equipment. He is both a con man and an incompetent engineer/builder. He needs to be put out of business, and people should no longer condone anything about this man's business......even if you think your amp sounds great, keep it to yourself please because there's no future for buying a Single Power amp.......at this point, I would rather have $9000 stolen from me than risk my house and my life by using a potential bomb as an amp. 

 WE NEED TO COME TOGETHER AS A COMMUNITY AND MAKE A TRIP OUT TO MIKHAIL'S FACTORY / RESIDENCE AND CONFRONT HIM ON HIS UNLAWFUL BUSINESS PRACTICE AND UNLAWFUL PRODUCT SPECIFICATIONS....... I tried to start a thread filing a class action lawsuit and for some reason this thread was shut down. But I have not given up.


----------



## purk

Thanks for doing this Nate.


----------



## PhilS

Quote:


  Originally Posted by *DavidMahler* /img/forum/go_quote.gif 
_even if you think your amp sounds great, keep it to yourself please because there's no future for buying a Single Power amp......._

 

That's silly. I'd be upset too if I lost money, and I'm not happy my amp may need to go to a tech to be checked out, but it sounds great, and many of us will probably keep our amps, either as is, or after we have them checked out. None of this excuses what Mikhail did, but we need to have a little bit of rationality here.


----------



## DavidMahler

Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_That's silly. I'd be upset too if I lost money, and I'm not happy my amp may need to go to a tech to be checked out, but it sounds great, and many of us will probably keep our amps, either as is, or after we have them checked out. None of this excuses what Mikhail did, but we need to have a little bit of rationality here._

 

I don't think anything I said was irrational.........the only reason to continue to endorse Mikhail's product in any way would be to endorse his business......this should not be......if you are happy with your amp that is great, cause you are lucky, but it is a sensitive subject for me and many others and I don't want his business to continue.


----------



## wnmnkh

Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_That's silly. I'd be upset too if I lost money, and I'm not happy my amp may need to go to a tech to be checked out, but it sounds great, and many of us will probably keep our amps, either as is, or after we have them checked out. None of this excuses what Mikhail did, but we need to have a little bit of rationality here._

 

Hmmm, seriously..... "as is"? after all of these unstable configuations, unprofessional work, under-spec components (nevermind about transformers, I mean a 50v switch for 520v and 220v voltage control?) and people can keep their amps... as is(are)?

 That's same thing as let that time bomb as is. People are really so fearless against high voltage and exploding caps...

 That's pretty much disservice to themselves if they let these faulty amps alone. And people should be discouraged from trading amps containing potential hazard, unless they have gone extensive repair and reworks done.


----------



## PhilS

Quote:


  Originally Posted by *DavidMahler* /img/forum/go_quote.gif 
_I don't think anything I said was irrational.........the only reason to continue to endorse Mikhail's product in any way would be to endorse his business......this should not be......if you are happy with your amp that is great, cause you are lucky, but it is a sensitive subject for me and many others and I don't want his business to continue._

 

Someone saying their amp sounds good is not endorsing Mikhail's product or Mikhail. It's saying the amp sounds good. And his business is not going to continue. Too many people know about him now.


----------



## PhilS

Quote:


  Originally Posted by *wnmnkh* /img/forum/go_quote.gif 
_Hmmm, seriously..... "as is"? after all of these unstable configuations, unprofessional work, under-spec components (nevermind about transformers, I mean a 50v switch for 520v and 220v voltage control?) and people can keep their amps... as is(are)?

 That's same thing as let that time bomb as is. People are really so fearless against high voltage and exploding caps...

 That's pretty much disservice to themselves if they let these faulty amps alone. And people should be discouraged from trading amps containing potential hazard, unless they have gone extensive repair and reworks done._

 

My amp has worked fine for 5 years, and many others have had their early SP amps for a long time. The number of catastrophic incidents is very low at this point, and not every amp is rife with the issues you raised. I've read this thread and others carefully, and assessed the risk, and while I will probably get mine checked out, it's up to the individual to decide whether to use his amp "as is" for a time. 

 Let's keep people informed of the facts, and let them make their own decision.


----------



## Mher6

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_Therein lies one of the major problems with trying to get a handle on how big this problem could be. I've only seen on Extreme in person and detailed pictures of another 2. All 3 have three different issues, but the other two appear minor compared with this one. 

 If you can safely access the inside of your Extreme there's a good chance that we could tell how the trafo is wired and if it's the same under-spec'd Hammond. I wouldn't trust shining a light through the trafo enclosure if it were my amp and had that little trafo box on it. You can see in the picture that Kevin Gilmore posted in the other SP thread what an Extreme with a properly spec'd trafo looks like. The transformer in that picture (a custom Electraprint) weighs more than the entire original Extreme did._

 

I posted high res pictures here and would appreciate it if you could take a quick look. Let me know if you need more detailed shots of certain sections.


----------



## wnmnkh

Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_My amp has worked fine for 5 years, and many others have had their early SP amps for a long time. The number of catastrophic incidents is very low at this point, and not every amp is rife with the issues you raised. I've read this thread and others carefully, and assessed the risk, and while I will probably get mine checked out, it's up to the individual to decide whether to use his amp "as is" for a time. 

 Let's keep people informed of the facts, and let them make their own decision._

 

Great, so as someone said earlier in original thread, rolling the dice for one's life....


----------



## scootermafia

This should probably be stickied. Good work Nate.

 Yeah, it is a paradox that such a good sounding series of amps could be so incredibly dangerous and badly designed. However, everyone must get used to the fact that an amp that's got serious safety issues can still sound good. Safety generally means that it's just going to fail way, way sooner than it should because its parts are misused, potentially maiming its owner in the process. It's like the three little pigs...the straw house is a perfectly working house by all appearances, but the wolf has no trouble blowing it down.


----------



## scootermafia

Hopefully David's plan will come to fruition as more and more people realize that their amp is actually dangerous and not fit for use or trade. Fixing its misspecced parts is a good call, but it seems that the amp's overall design may have problems too, maybe there are some unfixable things. Everyone that's within a day's drive from Colorado should meet up to confront him. I'm still amazed nobody has driven to his house to talk to him face to face.


----------



## PhilS

Quote:


  Originally Posted by *wnmnkh* /img/forum/go_quote.gif 
_Great, so as someone said earlier in original thread, rolling the dice for one's life...._

 

Yeah, let's use hyperbole as much as possible. That's helpful.


----------



## Born2bwire

Why does this not surprise me...


----------



## n_maher

Quote:


  Originally Posted by *Mher6* /img/forum/go_quote.gif 
_I posted high res pictures here and would appreciate it if you could take a quick look. Let me know if you need more detailed shots of certain sections._

 

Could you post a picture of the top side of the amp? Does it use a small metal enclosure to cover the transformer?

 Based on the way that your power trafo is wired, specifically that it has the exact same color coding and layout of the wiring, I'd guess that your amp uses the same Hammond transformer. 
	

	
	
		
		

		
			





 And as much as is possible I'd appreciate it if folks would discuss Mikhail and his business practices in other threads. This thread, like the two others like it (for now?) is meant as a way for owners to identify serious issues with their amps. I once saw Mikhail bring 10 or more Extremes to a NY regional meet so unfortunately there could be a lot of these out there.


----------



## kevin gilmore

Quote:


  Originally Posted by *Mher6* /img/forum/go_quote.gif 
_I posted high res pictures here and would appreciate it if you could take a quick look. Let me know if you need more detailed shots of certain sections._

 

Ok, this is clearly the hammond 266n12 transformer used in exactly
 the same WRONG way as monoboy's unit.

 Telltale signs
 Black and White winding (110v)
 Orange and Brown winding (110v)
 Red and Blue winding (6.3v)
 Grey and Yellow winding (6.3v)

 mrarroyo's transformer is clearly one of the hammond 300 series
 likely the 378x.

 Telltale signs
 Red, Violet, Red/yellow, red high voltage winding
 yellow, yellow/black, yellow winding (5V not used)
 green, green/yellow, green (6.3 VAC)
 Brown, Brown/yellow, Blue/yellow, Blue (one of the 2 primary windings)
 White, White/black, Black/red, Black (other primary winding)


----------



## mrarroyo

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_ ...

 mrarroyo's transformer is clearly one of the hammond 300 series
 likely the 378x.

 Telltale signs
 Red, Violet, Red/yellow, red high voltage winding
 yellow, yellow/black, yellow winding (5V not used)
 green, green/yellow, green (6.3 VAC)
 Brown, Brown/yellow, Blue/yellow, Blue (one of the 2 primary windings)
 White, White/black, Black/red, Black (other primary winding)_

 

Sorry for the basic question, but is the potential 378X transformer in my MPX3 a good thing or a bad thing? Thanks.


----------



## kevin gilmore

Quote:


  Originally Posted by *mrarroyo* /img/forum/go_quote.gif 
_Sorry for the basic question, but is the potential 378X transformer in my MPX3 a good thing or a bad thing? Thanks._

 

I'm pretty sure that is a good thing. Knowing the exact model number
 would make it much easier. Some of the 300 series are only 3 amps
 on the filament (not enough) some are 6 amps which should run
 most of the power hungry tubes (6bl7). Still temperature is the
 key here. If its getting massively hot, then you are probably going
 to want to do something about it.

 more info
http://www.hammondmfg.com/300series.htm


----------



## mrarroyo

Kevin, I can lay my hand on the transformer cover all day long. It is warm but not hot. BTW, Mikhail was paid to install the Supra transformer. I have never removed the transformer case but the original cables were cut when the Supra was installed. I sure hope he did it because otherwise I lost money (nothing new w/ Singlepower, I know). Thanks.


----------



## John D.

Quote:


  Originally Posted by *moonboy403* /img/forum/go_quote.gif 
_I just wanna say that it doesn't mean anything really. An amp can fail at any given moment. My Extreme was issue free through two previous owners, but it crapped out on me one day._

 

Now that all of us Extreme owners are wondering if our amps are going to explode at any minute. I was wondering if we are any better off with any other brand headhone amps. It doesn't appear that there is any regulating body connected with headphone amps, such as UL (underwriters laboratories) to assure anyone that these products are safe for consumers. Am I wrong about this ? maybe some of the big international companies comply. But what about all the smaller guys selling amps? Especially the ones made in China?


----------



## Happy Camper

I hope this thread can be done effectively because this is a serious issue for the membership. This amp is of concern to a lot of people and help from our senior members with the experience is needed and appreciated. What we don't need is sensationalism of possible hazards. Lets find the problems and offer direction. 

 This is a hobby industry and the things being found with SP are probably more wide spread than them. If the effort to find this problem can be put to all products that haven't been submitted to the proper certifications, we would all be better for it. This is the nature of buying on the internet. There are no safeguards or assurances and a world wide economy has people from Bengal, India buying a product made in Denver. That this community has the responsibility to protect itself and keep an eye out for these things is a credit to Head Fi.


----------



## robm321

Thanks Nate for alerting everyone to this serious problem.


----------



## TreAdidas

I agree with this:
  Quote:


  Originally Posted by *DavidMahler* 
_the only reason to continue to endorse Mikhail's product in any way would be to endorse his business......this should not be......if you are happy with your amp that is great, cause you are lucky, but it is a sensitive subject for me and many others and I don't want his business to continue._

 

And I agree with this:
  Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_None of this excuses what Mikhail did, but we need to have a little bit of rationality here._

 

One should not chastise anyone else for saying they like the sound of their Singlepower amp. Likewise no one should write off the safety concerns that have been brought up here. We all agree there is a problem and each of us is trying to figure out our best course of action. No one is trying to piss off other members who are suffering through the same thing. People directing their anger over raw deals with Singlepower to other members because they say they like something is futile. 

 Our frustration (and I know that is putting it politely) is with *Singlepower,* not each other. Let's keep that in mind and help each other out. So far that is what is happening here in this thread.


----------



## TreAdidas

Quote:


  Originally Posted by *DavidMahler* /img/forum/go_quote.gif 
_WE NEED TO COME TOGETHER AS A COMMUNITY AND MAKE A TRIP OUT TO MIKHAIL'S FACTORY / RESIDENCE AND CONFRONT HIM ON HIS UNLAWFUL BUSINESS PRACTICE AND UNLAWFUL PRODUCT SPECIFICATIONS....... I tried to start a thread filing a class action lawsuit and for some reason this thread was shut down. But I have not given up._

 

I was laid over in Denver on a flight to San Diego last week and I recalled that Singlepower's shop is or at least was right by the airport. The thought definitely crossed my mind.


----------



## thathertz

DavidMahler;5897595 said:
			
		

> EDIT: My anger is not directed at you sorry....QUOTE]
> 
> No problem. I fully understand the point you are making.
> 
> ...


----------



## nurxhunter

Withdrawn. Thanks for all concern.


----------



## Mher6

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_Could you post a picture of the top side of the amp? Does it use a small metal enclosure to cover the transformer?

 Based on the way that your power trafo is wired, specifically that it has the exact same color coding and layout of the wiring, I'd guess that your amp uses the same Hammond transformer. 
	

	
	
		
		

		
		
	


	




 And as much as is possible I'd appreciate it if folks would discuss Mikhail and his business practices in other threads. This thread, like the two others like it (for now?) is meant as a way for owners to identify serious issues with their amps. I once saw Mikhail bring 10 or more Extremes to a NY regional meet so unfortunately there could be a lot of these out there._

 

What's the worst that could happen if the transformer fails? Could it potentially damage my source or headphones?


----------



## n_maher

Quote:


  Originally Posted by *Mher6* /img/forum/go_quote.gif 
_What's the worst that could happen if the transformer fails? Could it potentially damage my source or headphones?_

 

I'm not qualified to answer that, sorry.


----------



## kevin gilmore

Quote:


  Originally Posted by *Mher6* /img/forum/go_quote.gif 
_What's the worst that could happen if the transformer fails? Could it potentially damage my source or headphones?_

 

2 seperate issues.

 1) extremes with the hammond 266n12 transformer.

 A primary to primary (which is the secondary) short (monoboys amp)
 could put a significant percentage (depending on where the short is)
 of the AC line onto the chassis. The fuse may or may not blow. And 
 current will flow from the chassis thru whatever low impedance it
 finds to ground/neutral. Likely thru another component like your source.
 At least on these units (all i've seen so far) the output capacitors are
 rated to take the full power supply voltage, so a shorted output cap
 is unlikely.

 2) mpx/ppx things.
 Almost all of these i have seen have output capacitor ratings between
 33% and 66% of the B+ line. (160 to 250 volt caps) (300 to 530 volt B+)
 Eventually these caps have to fail because the turn on thump when the 
 tube warms up typically goes way above B+/2. In fact the voltage on tyson's
 amp is a steady state of 280 volts with 250 volt rated caps. Definitely
 not a good thing. With high impedance heaphones, the headphones will
 definitely fry. Best thing i can do for these things is series back to
 back 5 watt zener diodes rated at 12 volts. And a 100ma fuse.

 As you get into the supra/sds things it gets far more complicated
 and the balanced units have additional problems. Voltron's amp for
 example has a 1200 volt power rail with 900 volt rated caps to light
 the gas tubes.


----------



## micaela

Ok - a very basic question. I've had my PPX3 Slam for 3 yrs or so. I am the 2nd owner & not sure how long the original owner used the amp. It is completely stock & has never been sent back to SP for upgrades or repairs. It has operated without any problems as long as I've had it. I've often left it on for weekends when I'm using it a few hours at a time - rather than turn it off & on several times. Should I be concerned & do I need to have it checked out? What are the chances that an amp that has operated perfectly for 4 or more years has one of the dangerous flaws being discussed here? I'm probably not alone in being a consumer without much technical knowledge & feeling a little uneasy & confused.


----------



## nurxhunter

"A primary to primary (which is the secondary) short (monoboys amp)
 could put a significant percentage (depending on where the short is)
 of the AC line onto the chassis. The fuse may or may not blow. And
 current will flow from the chassis thru whatever low impedance it
 finds to ground/neutral. Likely thru another component like your source."

 The ground pin on the AC cord would not directly ground the chasis; rather, current would flow into the source, and from it to ground?

 I though the reason for the grounding pin on three prong cords and outlets was to prevent the instance of poor design, or poor luck, so that the the chassis conducted to ground, and not to another electronic or biological component.


----------



## kevin gilmore

You might want to look at some of those pictures where the green wire
 from the IEC input block is connected to chassis ground by scraping some 
 of the paint away from only the inside, usually without a star washer.

 And i know that some of you use cheater plugs to get rid of ground loops.


----------



## Uncle Erik

Nurxhunter, it's good to hear that you haven't had a failure and have had good performance from your amps.

 When it comes to failure, electronics are not like cars and you don't necessarily get warning signs. Further, there are multiple modes of failure - some much more dangerous than others. If you want to use a car analogy, for example, a bad alternator will drain your battery and eventually leave your car dead.

 A bad alternator, however, will not leave your car dangerous to the touch. It is also unlikely to start a fire inside your car. Most of what happens to a car results in it not running. A car that isn't running (with a few exceptions) isn't life threatening. Another important point is that cars are thoroughly inspected by the government, are built to various safety standards and the manufacturers have deep pockets - if they screw up they're liable. There's absolutely nothing like this kind of regulation, oversight and liability when you're building amps in a garage.

 An amp that shorts to the chassis is potentially life threatening.

 Another thing I want you to keep in mind is that electronics do not improve with age. Every resistor, cap, transformer, diode, switch, and tube has a rated lifespan. You can even look up the manufacturer's lifespan ratings at Digikey and Mouser. Every part inside an amp is due to fail sooner or later.

 New components can take more abuse than ones that have been abused. If something has held up to abuse for several years, it will not have an infinite lifespan or anything close to a normal one.

 It's easy to think of amps as static and with no wear items besides the tubes. But it's not like that. Everything inside is going to fail sooner or later. What happens during a failure depends on which part goes. There are lots of thing that happen when you subtract a part, which can then lead to the failure of other parts.

 I urge you to give your amp a more thorough checking than taking a peek at the transformer and sniffing it. You need to know its rating. You need to know whether it is being run too hard. Since you have a family, do it for their sake. You wouldn't want to leave it on one night and have it start an electrical fire in your house. Like I said, components do not last forever. You can keep rolling the dice, but you know you can't win every round.


----------



## Happy Camper

Unc,

 I respect your opinion and glad to have your experience applied to our problem. What you state has truth to it in abstract so I won't argue with your approach. But what you say can be said for anybody's amp. Are the ZDs certified, RSA, LD, DV? This should be a wake up call for everybody in this hobby to take a closer look at what is sold on these forums. We do not have credible accountability to protect us from this thing happening to any device that has 120/240v plugged to it. The same "death threats" were used to justify why no one should buy from VD. The thrust was motivated by the "perceived" high markups and not by known evidence of failure. For us to have credibility in protecting our members, we have to be neutral in our biases and stick to the facts of the issue. 

 Thank you Mr. Gilmore for putting your time and considerable knowledge to our problem.


----------



## nurxhunter

Wise to check out amps, despite fine function and great sound

 Apparently, DIY tube amps have been sold (think Heath, Lafayette, Dynaco) for decades. Surely, dopes on occasion have put these together. 

 No where can I find warning not to buy old DIY amps. Everywhere I see warnings not to open them if not educated in the craft.

 Dr. Kevin mentions the use of cheater to bypass ground. Shouldn't that elicit MUCH more concern? Old news. Audiophile like to live on the edge?

 So, my perspective is that the Extreme is likely not a live grenade, a ticking time bomb, or an electrocutioner. It will not likely blow up, or burn down a house. The instances so far--at worst--seem to be a fried transformer (not a surprise in this field at all), and poor craftsmanship (not 'shocking' in this field), maybe even deceit (well, that is interesting; see below). 

 The risks here are far lower than buying and using an 807-based amp. No one has ever become hysterical over those naked tube-end caps that could be transmitting 500V right into a user, or child, or cat, though that risk is quite real.

 If users are checking out the Extreme, they should certainly check out any DIY tube amp. Old news. 

 The real news is that THE leading vendor of tube headphone amplifiers has scammed some very knowledgeable, even 'supreme' audiophiles, for YEARS. 

 Now, THAT is shocking.


----------



## nurxhunter

This cost me $2. Works quite well on the SinglePower amplifier Allen Hex Screws.

 Make sure it is VERY WELL SEATED in the bolt and apply considerable vertical pressure down into the bolt so the key does not slip and strip the screw, then, you WILL be screwed.

 The problem is, I believe, that the thick case applies outwards pressure on the bolt, making the friction too high to turn easily. You might be better off with a touch of WD40 than heat. Heating the bolt will expand the bolt; logically, this could make things worse.

 A handled hex key perpendicular to the shaft would be ideal to allow more torque--I could not get this. 

 Craftsman 946730 has worked well for me in all the SP amps.


----------



## PhilS

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_ I have scheduled the amp. for a checkup. I do this with my cars (they are older) every six months, and it seems warranted to do for Extreme as well, and I will report back results._

 

After you have your amp checked out, if you are satisfied with the tech you use, please consider posting the relevant information in this thread:

http://www.head-fi.org/forums/f5/sin...thread-437808/


----------



## tohenk2

Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_That's silly. I'd be upset too if I lost money, and I'm not happy my amp may need to go to a tech to be checked out, but it sounds great, and many of us will probably keep our amps, either as is, or after we have them checked out. None of this excuses what Mikhail did, but we need to have a little bit of rationality here._

 


 I absolutely don't think te advice to downplay the good sides of this amp is silly. A lot of people only read a few posts. If in those post a item gets the label "good" they might buy it. And in that way you could be indirectly contibuting to their death. Electrocution, burning down the house and explosion hazard are NOT to be taken lightly. In my opinion it overshadows any merrit this product might have.

 Along the same lines keeping the amp "as-is" is - if you know of the danger - downright irresponsible. 

 Car manufacturers (have to) pay for recall of products if anything this dangerous is found - can't SP be forced to do the same?


----------



## spritzer

SP would just file for bankruptcy and without any holdings there is nothing that can be done. Who knows how many amps are out there (hundreds?) which all have to be fixed.


----------



## Happy Camper

Quote:


  Originally Posted by *tohenk2* /img/forum/go_quote.gif 
_I absolutely don't think te advice to downplay the good sides of this amp is silly. A lot of people only read a few posts. If in those post a item gets the label "good" they might buy it. *And in that way you could be indirectly contibuting to their death. Electrocution, burning down the house and explosion hazard are NOT to be taken lightly*. In my opinion it overshadows any merrit this product might have.

 Along the same lines keeping the amp "as-is" is - if you know of the danger - downright irresponsible. 

 Car manufacturers (have to) pay for recall of products if anything this dangerous is found - can't SP be forced to do the same?_

 

Perhaps if there was an incident to justify it. Car recalls usually occur when the threats happen and people die. The products are not certified, the govt. won't get involved in internet commerce that isn't taxed, the legal route won't involve enough money to make it worthwhile to pursue. The options are limited and minimal. Best to do it the old fashion way, let the community deal with its scum.


----------



## PhilS

Quote:


  Originally Posted by *tohenk2* /img/forum/go_quote.gif 
_I absolutely don't think the advice to downplay the good sides of this amp is silly. A lot of people only read a few posts. If in those post a item gets the label "good" they might buy it. And in that way you could be indirectly contibuting to their death._

 

Yeah, right, people are that stupid. If someone says: "It's too bad we're having all these problems with these SP amps, because mine really sounds great," that comment will cause others to completely ignore 100 other posts saying the amps are likely to blow up like hand grenades. Give me a break. 
	

	
	
		
		

		
		
	


	




 The problems with these amps are discussed at length on many, many threads, and nobody is going to miss it. 

 And the suggestion that people who comment on the "good" aspects of these amps might be indirectly contributing to someone's death is downright offensive and completely uncalled for. I request that you remove it.

  Quote:


  Originally Posted by *tohenk2* /img/forum/go_quote.gif 
_Electrocution, burning down the house and explosion hazard are NOT to be taken lightly. In my opinion it overshadows any merrit this product might have.

 Along the same lines keeping the amp "as-is" is - if you know of the danger - downright irresponsible. 
_

 

For crying out loud, nobody is taking it lightly. Every one of these SP threads has the same problem of "political correctness." Any post that doesn't say that Mikhail is the anti-Christ, his amps suck in every conceivable aspect, they're extremely dangerous and death is likely to result from just touching one, etc., is judged as "taking the issue lightly," or something to that effect. This is just absurd.

 Moreover, IMO, your type of post actually undermines the seriousness of the safety argument. I have had several people comment to me privately that they don't understand the reason for some of the hyperbole on some of these threads, and they wonder if some folks have some sort of agenda. It's important that the truth about these safety issues not get obscured by hype. 

 Look, the facts are the facts, and they speak for themselves, and everybody is being made aware of them. And once the facts are made known, everybody is free to evaluate the risks and make their own choice. I'd prefer to make my own choices and not have someone else, who apparently thinks they know better than I do as to what's best for me, tell me what to do with _my _amp in _my _house. It's a free country -- at least it is here in the USA. 

 So let's continue to share the _facts_, and please keep the judgmental BS and stance of moral superiority to yourself.

 P.S. The fact that I started a thread to identify techs and repair shops where people might be able to get their SP amp checked out and repaired shows that I am not taking this issue lightly, and that I don't think others should just ignore the issue.


----------



## mourip

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Ok, this is clearly the hammond 266n12 transformer used in exactly
 the same WRONG way as monoboy's unit.

 Telltale signs
 Black and White winding (110v)
 Orange and Brown winding (110v)
 Red and Blue winding (6.3v)
 Grey and Yellow winding (6.3v)

 mrarroyo's transformer is clearly one of the hammond 300 series
 likely the 378x.

 Telltale signs
 Red, Violet, Red/yellow, red high voltage winding
 yellow, yellow/black, yellow winding (5V not used)
 green, green/yellow, green (6.3 VAC)
 Brown, Brown/yellow, Blue/yellow, Blue (one of the 2 primary windings)
 White, White/black, Black/red, Black (other primary winding)_

 

I cracked open my case tonight after seeing this sobering thread. I seem to have the oddly wired 6.3v filament transformer based upon Kevin's helpful color guide. The rest of the amp looks to be better turned out than the one in Nate's photos. My tube sockets have a small PCB adaptor between the circuit board and the tube sockets, no air wires. Wire dressing looks good although the filament rectifier looks a bit small. Hex headed screws for the chassis.

 Two questions.

 1. Nate could you post the wire diagram you mentioned. I am having a hard time figuring out how SP got the high voltage in a correct range. In my mind I have one half of the transformer stepping down for 6.3v and the other half wired "backwards" for the HV. It seems to me that the multiplier for the HV would be way high?

 2. Kevin. Would the Hammond 378C or 378CX be a drop in replacement or would circuit values also need to change? I have done enough building to replace the TX as a drop-in but I would be uncertain about changing resistor values.

 Thanks for the thread and your input. Boy, my Extreme has been on the shelf since buying my Tekton amp and I was getting ready to sell it. Not sure if I could sell it stock in good conscience now. Too bad as it is a great sounding amp and had no issues in two years.

 Best,

 Paul


----------



## kevin gilmore

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_
 2. Kevin. Would the Hammond 378C or 378CX be a drop in replacement or 
 Paul_

 

That is way to high of a high voltage. An extreme really wants to
 be 150 to 180 volts rectified and filtered.

 There is an edcor transformer that is cheap that works.
EDCOR - XPWR039


----------



## kokohore

Internal pics of my Extreme taken some time ago











 Though the unit looks relatively new (Feb 2007), the transformer is probably the 'WRONG' hammond 266n12 according to Kevin's guide...
	

	
	
		
		

		
		
	


	




 Correct me if I'm wrong.


----------



## mourip

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_That is way to high of a high voltage. An extreme really wants to
 be 150 to 180 volts rectified and filtered.

 There is an edcor transformer that is cheap that works.
EDCOR - XPWR039_

 


 Thanks Kevin. Would you just wire the secondaries in parallel? 110 +110 and 6.3 + 6.3?

 Best,

 Paul


----------



## n_maher

Paul,
 Yes, both secondaries would be connected in parallel.


----------



## kevin gilmore

The "UPGRADED" transformers for the supra extremes is now known to be
 the hammond 266PA14. Wired in the same awful way. Better. But still
 not sufficient.


----------



## mourip

Nate. Thanks for the help with the wiring. I just wanted to be sure. The Edcor TX sounds like a near drop-in except that it will not fit underneath the transformer enclosure, not a deal breaker if it maintains or improves the sound quality... and makes the amp a good long term and safe keeper.

 As I look through this thread and a couple other SinglePower "Lovefest" threads one thing that really stands out is how wildly different the same SP model can be on the inside. I think that I can see some progress in certain cases. He went from hand wired to PCB and from oddly wired PCB to more logical PCB layouts but it seems that he was very erratic, sometimes turning out a well built device, other times turning out odd or dangerous stuff. My amp looks pretty good except for the "power" transformer. Wiring is acceptable, rectifier has some heat transfer tape on the back side, caps look properly spec'ed for the relatively low voltage Extreme circuit. Maybe he named it the Extreme because he was pushing the transformer to an extreme condition 

 Lets share our repair, mod, and rehabilitation findings and make this a really useful thread...


----------



## nurxhunter

That is way to high of a high voltage. An extreme really wants to
 be 150 to 180 volts rectified and filtered.

 "There is an edcor transformer that is cheap that works.
 EDCOR - XPWR039"

 But.............


 XPWR039
 Rohs
 Tube Amplifier Power Transformer
 Power transformer from 120V or 240V, 50/60Hz. to dual 110V at 250mA and dual 6.3V at 4A.


 So, the question might be--'cause I am ignorant--doesn't the Extreme need at least 6 A. Each 6080 is 2.5 amp X 2 = 5.0 + 6SN7 = 0.6. Total = 5.6A current draw in an extreme?

 Thanks much.

 Also

 "The "UPGRADED" transformers for the supra extremes is now known to be the Hammond 266PA14. Wired in the same awful way. Better. But still not sufficient."

 266PA14 

 14V @ 6A

 7V @ 12A

 This would seem more like it.

 Is the Edcor an option at 4A?


 Thanks for guidance to all.


----------



## kevin gilmore

dual secondaries in parallel === 6.3 volts at 8 amps.
 dual high voltage in parallel === 110 volts at .5 amp.


----------



## nurxhunter

Thanks, Kevin--nice of you to help the weak.

 If one of ordinary skill in field can easily replace transformer--and wire it properly (can any tech do this--do you think based on pictures on the site?), which of the two transformer would you recommend.

 The EDCOR has better aesthetic appeal, but if the Hammond upgrade is the one--please advise the best option and I may simply move forward and order. May as well get the fix over with ASAP.

 BTW--what do you have on yours--looked more like EDCOR.

 Much thanks.


----------



## Happy Camper

If I can ask for the Platinum owners, should we be concerned with our tranny issues? I figure we need the bleeder loads on the caps.


----------



## PhilS

Quote:


  Originally Posted by *Happy Camper* /img/forum/go_quote.gif 
_If I can ask for the Platinum owners, should we be concerned with our *tranny issues*?_

 

That sentence caused me to do a double take.


----------



## Bolder

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_Thanks, Kevin--nice of you to help the weak.

 If one of ordinary skill in field can easily replace transformer--and wire it properly (can any tech do this--do you think based on pictures on the site?), which of the two transformer would you recommend.

 The EDCOR has better aesthetic appeal, but if the Hammond upgrade is the one--please advise the best option and I may simply move forward and order. May as well get the fix over with ASAP.

 BTW--what do you have on yours--looked more like EDCOR.

 Much thanks._

 

The Hammond would NOT be a *suggested* upgrade. That transformer is what *was* sold as an upgrade by Singlepower. It still is wired using the primary as the feed to the high voltage section. Not very safe and it pulls current from the secondaries. 

 The EDCOR is what Kevin has come up with for a reasonable cost replacement that is SAFE. Be aware that EDCOR does not stock any transformers. Everything is a custom build for them. Once an order is placed it can take 3-4 weeks for them to deliver.

 The transformer used in Kevin's Extreme is a custom unit made by Electraprint. I believe it costs about twice as much as the EDCOR and takes up more real estate.

 If you can easily access the screws that hold the transformer cover in place, changing out the transformer should not be too big a problem. If you have a circuit board Extreme, disassembly is a PITA. It will take awhile. You will have to unsolder all the tube sockets and remove most of the controls, switches and connectors. You may have to drill some more holes to fit the mounting pattern of the new transformer. Parts cost may not be too much, but labor cost will be more.


----------



## thathertz

Quote:


  Originally Posted by *Happy Camper* /img/forum/go_quote.gif 
_If I can ask for the Platinum owners, should we be concerned with our tranny issues?_

 

 Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_That sentence caused me to do a double take. 
	

	
	
		
		

		
		
	


	


_

 

Thanks for that Phil...made me laugh this morning


----------



## kevin gilmore

The other 266pa14 hammond transformer is wrong for the same reasons as the
 other transformer. Way underpowered and unsafe when one of the primarys is
 used as a secondary.


----------



## nurxhunter

I have the 2007 revision A board. It appears that I can get under the board and with a needle nose or small wrench get to the screws holding the transformer cover, assuming the bolt comes of easily from the screw. Veteran techs are clever on how they need to do these things.

 If not, I was thinking of telling the tech (if required) to drill two clean holes on the top of the Extreme, which can be covered afterward with black plastic snap-in-plugs, or left as vent holes. I have a mind to do what Keven did--simply leave the cover off, like the MPX3 and PPX3 when they first came out.

 When I call the tech I can give him info for ordering, or order myself (he does not charge more for parts I source).

 Would you know the specifications and Model# of the Transformer from Electroprint?
 Maybe Kevin or you could share this info. 
 What should the spec. be for primary(s) and secondaries be?

 True, if the tranny can be operated on without major surgery, the cost will be far less. Simple R&R.

 Thanks+++

 Might also ground ground the RCA inputs (see pic)?


----------



## kevin gilmore

skylabs unit. Same burned up transformer. More lousy/cold solder joints
http://gilmore.chem.northwestern.edu/skylab-1.jpg
http://gilmore.chem.northwestern.edu/skylab-2.jpg
http://gilmore.chem.northwestern.edu/skylab-3.jpg
http://gilmore.chem.northwestern.edu/skylab-4.jpg
http://gilmore.chem.northwestern.edu/skylab-5.jpg
http://gilmore.chem.northwestern.edu/skylab-6.jpg
http://gilmore.chem.northwestern.edu/skylab-7.jpg
http://gilmore.chem.northwestern.edu/skylab-8.jpg
http://gilmore.chem.northwestern.edu/skylab-9.jpg
http://gilmore.chem.northwestern.edu/skylab-10.jpg
http://gilmore.chem.northwestern.edu/skylab-11.jpg

 after having a number of units i now notice that the holes for
 the transformer cover and the transformer are never in the same
 place from unit to unit.

 Have not seen a balanced extreme yet, but with lots of pictures
 of mpx3 extremes, ppx3 extremes, and supra extremes i have to
 conclude that every single transformer is burning up.


----------



## thathertz

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_skylabs unit. Same burned up transformer. More lousy/cold solder joints
 <<<...SNIP.....>>>
 the transformer cover and the transformer are never in the same
 place from unit to unit.

 Have not seen a balanced extreme yet, but with lots of pictures
 of mpx3 extremes, ppx3 extremes, and supra extremes i have to
 conclude that every single transformer is burning up._

 

Is this one of the earliest PCB models?
 Anyone know when he switched from point to point to PCB?


----------



## n_maher

Quote:


  Originally Posted by *thathertz* /img/forum/go_quote.gif 
_Is this one of the earliest PCB models?
 Anyone know when he switched from point to point to PCB?_

 

I think it's hard to establish a time line since Mikhail was upgrading people's PPX3's into Extremes in addition to building new Extreme's on dedicated PCBs. 

 I have yet to see a PTP extreme but on his other amps I think that he switched back and forth depending on the level of "customization so again it's hard to look at that factor and try and determine when the amp was built.


----------



## Skylab

Well, quite clearly I made a good decision to stop using my Extreme once I heard about this problem. 

 In a month, I have gone from using SP amps in 2 of my 3 headphone rigs to none. Now the MPX3 is gone, and the Extreme looks wrecked. That flat out SUCKS. $2K down the toilet. That is the worst loss I have taken in 30 years of being an audiophile.


----------



## moredes

Quote:


 Anyone know when he switched from point to point to PCB? 
 

I know this is a mainly a discussion about Extremes, but I had a correspondence with SACD-Lover a little over a year ago when I was trying to establish the build date for my standard MPX3. I'd bought mine used, and Earl was trying to guesstimate to help me out. 

 He theorized that PCB's were launched some time in early 2006. He said he'd taken delivery of two new MPX3's in late 2005, and they were P2P, but quite soon afterwards, SP went to PCB's.... however, my board is dated "Jan 2005". I only found that out after cracking the box because of this fiasco.

 Sky, my condolences. It's no consolation, but I'm glad it's only money.


----------



## kevin gilmore

Quote:


  Originally Posted by *thathertz* /img/forum/go_quote.gif 
_Is this one of the earliest PCB models?
 Anyone know when he switched from point to point to PCB?_

 

Hand wired models were an extra cost option. Significantly
 extra cost.

 Pretty sure i have pictures of a mpx circuit board circa 2005...


----------



## Happy Camper

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_Well, quite clearly I made a good decision to stop using my Extreme once I heard about this problem. 

 In a month, I have gone from using SP amps in 2 of my 3 headphone rigs to none. Now the MPX3 is gone, and the Extreme looks wrecked. That flat out SUCKS. $2K down the toilet. That is the worst loss I have taken in 30 years of being an audiophile._

 

Wow. Sorry to see those pics Skylab. What a piece of crap build. My wife solders better than what I saw in those pics. As good as they sound, I would not recommend another SP product again.


----------



## mourip

My Extreme has a PPX3 board marked as Rev3 2004. It looks much like Skylabs but has no extra heater capacitance tacked on to the PCB and instead of wires connecting the tube sockets to the main PCB it has some small round adaptor PCB boards. The boards look good but make it nearly unworkable to take the entire mainboard out. I got the transformer cover off yesterday and saw similar yellowing on the bobbin. My SP has relatively few hours on it so it did not have time to literally "burn in" yet. I got to the TX cover screws by drilling through the PCB. The screws are torx head and drilling did not compromise any PCB traces. I may also replace the heater rectifier with a higher spec'd one. 25A should do. Mine looks like it might be 10A.

 Overall the soldering looks better than some photos I have seen and there are fewer wires going through holes in what seems like it was an ill-concieved after thought. Whoever built it was having a lucid day.

 I am probably going to call Jack at Electra-Print tomorrow and get a quote for a nice over spec'ed tranny. Depending upon his price I will buy one or else get one of the Edcor ones. In my case I believe that the TX is all that separates the amp from being safe. I figure that if I do the work myself it will cost me about $150 to be back in the game.

 Who knows, maybe it will sound better 
	

	
	
		
		

		
			





 Best,

 Paul


----------



## HeadphoneAddict

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_Well, quite clearly I made a good decision to stop using my Extreme once I heard about this problem. 

 In a month, I have gone from using SP amps in 2 of my 3 headphone rigs to none. Now the MPX3 is gone, and the Extreme looks wrecked. That flat out SUCKS. $2K down the toilet. That is the worst loss I have taken in 30 years of being an audiophile._

 

Maybe you SP guys could start a group by on custom transformers?

 Do I need to be worried about my SP Square Wave XL balanced SS amp?


----------



## Skylab

Needs more than just the tranny, unfortunately. But yeah. 

 And I really owe Nate a debt of gratitude - my transformer had actually already started to short. It was truly and literally an accident ABOUT to happen. I stopped using it pretty much just in time.


----------



## spritzer

Quote:


  Originally Posted by *HeadphoneAddict* /img/forum/go_quote.gif 
_Do I need to be worried about my SP Square Wave XL balanced SS amp?_

 

We aren't sure about that one, it really depends on what boards are in your actual unit. It would certainly be worth the time to open it up and take a few pictures.


----------



## jsaliga

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_It was truly and literally an accident ABOUT to happen. I stopped using it pretty much just in time._

 

I know it truly sucks seeing good money go down the drain. But seeing a lot of the pictures that have been showing up here and elsewhere makes me downright fearful for anyone using a Singlepower amp. Too many of these things are turning up with shoddy build quality to trust any of them. I am sure some were quite well made before Mikhail turned into Mr. Hyde, but why take chances? SP amp owners should stop using their amp until they get it checked out by a professional who really knows what he's doing.

 Skylab, I think you made the right choice. It's better to be safe than sorry.

 --Jerome


----------



## n_maher

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_I am probably going to call Jack at Electra-Print tomorrow and get a quote for a nice over spec'ed tranny. Depending upon his price I will buy one or else get one of the Edcor ones. In my case I believe that the TX is all that separates the amp from being safe. I figure that if I do the work myself it will cost me about $150 to be back in the game._

 

Don't over-spec the trafo, there's no need. And before you contact Jack let me conduct a short private conversation with someone and we'll see about posting the specs that the replacement trafo should need so that you can save yourself (and Jack) a bunch of time.

 And Rob I'm glad to hear that we caught your amp in time before it did any real damage. The trafo actually didn't look all that bad in Kevin's pics (far better than his did) but I guess that looks can be deceiving.


----------



## nurxhunter

Much thanks, Nate, for all help to all. Right now, the EDCOR is the recommended replacement, as I understand. Based on some posts here and there, they make a nice sounding tranny.


----------



## kevin gilmore

Quote:


  Originally Posted by *HeadphoneAddict* /img/forum/go_quote.gif 
_Maybe you SP guys could start a group by on custom transformers?_

 

good idea

 Do realize that the transformer cover will never fit on any of the replacment transformers,
 and that extra holes in many of the chassis will be visible around the area of the transformer.

  Quote:


  Originally Posted by *HeadphoneAddict* /img/forum/go_quote.gif 
_Do I need to be worried about my SP Square Wave XL balanced SS amp?_

 

If icariums unit is any indication, sooner or later one of the transistors
 inside is going to short out, then a couple of resistors toast. Since
 its capacitively coupled output, no damage to the headphones will occur.
 And hopefully the wall brick has a fuse inside.


----------



## thathertz

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Hand wired models were an extra cost option. Significantly
 extra cost.

 Pretty sure i have pictures of a mpx circuit board circa 2005..._

 

Thanks for that info Kevin. 

 Sorry to hear about your misfortune Skylab. I'm having an outboard 
 transformer built for my MPX3 by an electrical engineer here in the UK. 
 Far from what I expected after a few weeks of ownership but a small price
 to pay for peace of mind.


----------



## thathertz

kevin gilmore;5918543 said:
			
		

> ......
> If icariums unit is any indication, sooner or later one of the transistors
> inside is going to short out, then a couple of resistors toast. Since
> its capacitively coupled output, no damage to the headphones will occur.
> ...


----------



## HeadphoneAddict

Quote:


  Originally Posted by *Spritzer* 
_We aren't sure about that one, it really depends on what boards are in your actual unit. It would certainly be worth the time to open it up and take a few pictures._

 

 Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_good idea

 Do realize that the transformer cover will never fit on any of the replacment transformers,
 and that extra holes in many of the chassis will be visible around the area of the transformer.



 If icariums unit is any indication, sooner or later one of the transistors
 inside is going to short out, then a couple of resistors toast. Since
 its capacitively coupled output, no damage to the headphones will occur.
 And hopefully the wall brick has a fuse inside._

 

Thanks for the help.

 I've opened the wall brick and it looks fine, and there is a fuse soldered in place inside the wall brick - I'm having trouble reading the value of the fuse but it looks like a low amperage fuse. The transformer inside the wall brick is not secured in place and that is the source of the rattle that I complained about last year. I'm trying to decide the best way to glue the transformer down, so if I decide to transport it it wont flex the wires till they break. I think have some liquid nails around here somewhere.

 I will try to get the amp open soon and post some photos of that. The amp has been powered up 24/7 for the last 13 months and still sounds very good, while only running a bit warm but never hot. I wonder if Icarium's problem was due to the 4-6 stacked Sq Wave boards in close proximity with improper ventilation, or maybe due to the aweful power supply. Mine was built in 2008, with supposedly "upgraded parts" over the 2007 version, and blackgate caps.


----------



## n_maher

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_Much thanks, Nate, for all help to all. Right now, the EDCOR is the recommended replacement, as I understand. Based on some posts here and there, they make a nice sounding tranny._

 

I'm not sure this is a correct statement. There is an Edcor that would appear to be close to working but it's untested. It is certainly an attractive option because of it's price but no one has put one in an Extreme yet to see how it measures. 

 And thathertz, it's not worth discussing what would happen if the output weren't capacitor-coupled, there's no option for it not to be and all Extremes were built this way.


----------



## kevin gilmore

Quote:


  Originally Posted by *thathertz* /img/forum/go_quote.gif 
_ 
 Kevin, hypothetically, if it didn't have capacitively coupled output, what 
 would the typical damage be?

 (sorry if I'm speaking OT)_

 

Any DC output coupled amplifier is subject to destroying your load
 (speakers, headphones) without proper protection. Tubes or solid
 state, does not matter. Definitely includes items such as Futtermans
 and Atmaspheres. (atmasphere uses fuses 
	

	
	
		
		

		
			





 )



 (electrostat's are different and really don't care)

 If you want a DC output coupled extreme, i did a thing called the bamaslama a while
 back. Uses some sand to keep the output at zero volts, and requires twice as many
 power supplys. Very few were built.


----------



## mourip

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_Don't over-spec the trafo, there's no need. And before you contact Jack let me conduct a short private conversation with someone and we'll see about posting the specs that the replacement trafo should need so that you can save yourself (and Jack) a bunch of time._

 

Thanks for the help Nate. I had already sent off an inquiry to Jack based upon an email exchange with Kevin. I asked for a quote for 117v primary with 120v@.5A secondary and 6.3V@10A secondary. I look foward to your input.

 Best,

 Paul


----------



## n_maher

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_Thanks for the help Nate. I had already sent off an inquiry to Jack based upon an email exchange with Kevin. I asked for a quote for 117v primary with 120v@.5A secondary and 6.3V@10A secondary. I look foward to your input.

 Best,

 Paul_

 

Paul,

 The issue here is that there are variations from amp to amp and I'm not sure there's a one-spec fits all solution. Your proposed specs will probably work but the rectified filament voltage may need adjusting via the dropper resistor or may just end up being a little on the low side. I wish there was a better answer but there isn't.


----------



## mourip

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_Paul,

 The issue here is that there are variations from amp to amp and I'm not sure there's a one-spec fits all solution. Your proposed specs will probably work but the rectified filament voltage may need adjusting via the dropper resistor or may just end up being a little on the low side. I wish there was a better answer but there isn't._

 

Thanks Nate. I did figure that given SP's "creative" approach to amp building I might end up needing to tweak a bit. My heater circuit has just one large capacitor after the rectifier. I guess some other amps have the tacked on extra capacitance and some a dropping resistor...


----------



## n_maher

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_Thanks Nate. I did figure that given SP's "creative" approach to amp building I might end up needing to tweak a bit. My heater circuit has just one large capacitor after the rectifier. I guess some other amps have the tacked on extra capacitance and some a dropping resistor..._

 

Yup, there's no one design for anything unfortunately. Thankfully the filaments don't care if you feed them exactly 6.3V.


----------



## XXII

Here are 2 pictures of my singlepower squarewave XL. I don't know if it's exactly the same as Larry's. I have replaced the floorwart with a Sigma22. I would appreciate any input on whether it is safe.


----------



## kevin gilmore

Nice packing job on that XL... I did not think mikhail could get that much in
 a package that small. Sure looks exactly like the same parts as the unbalanced
 version i have seen with the black gate output caps.
 at least 2 of the resistors in there show changes indicating heat...
 no change in circuit diagram either.


 OK, real numbers from skylab's unit whose transformer is sinking slowly into the west.

 transformer on for about 5 minutes. After that the voltage starts to sink.
 With 117 VAC input...

 DC filament voltage measured at the tubes 5.11 VDC
 Plate voltage measured at the tubes 97 VDC
 Cathode voltage at the tubes 47 VDC

 My repaired unit with the electraprint transformer
 DC filament 6.2 VDC
 Plate voltage 149 VDC
 Cathode voltage at the tubes 72 VDC

 So its real easy to determine how much trouble your particular unit is in.
 Just measure the filament voltage.


----------



## mourip

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_With 117 VAC input...

 DC filament voltage measured at the tubes 5.11 VDC
 Plate voltage measured at the tubes 97 VDC
 Cathode voltage at the tubes 47 VDC

 My repaired unit with the electraprint transformer
 DC filament 6.2 VDC
 Plate voltage 149 VDC
 Cathode voltage at the tubes 72 VDC

 So its real easy to determine how much trouble your particular unit is in.
 Just measure the filament voltage._

 

Talk about sag...

 Would you say that those new HV values are now appropriate for the circuit? Did you need to replace/adust any resistor values?

 Thanks!


----------



## kevin gilmore

Well that depends on whether or not you subscribe to the broksie version
 for optimal bias of the output tubes. Clearly with 2 sections in parallel you
 can go much higher. So a B+ of 180, and a current of 140ma with a cathode
 of 500 ohms is going to give a lower output impedance of about 21 ohms
 into a 32 ohm load.

 B+ of 210 and a current of 190ma gives lower distortion...

 And then its gonna really heat up the room.

 and max power is a B+ of 230 and a current of 220 ma
 For a grand total of 160 watts.


----------



## HeadphoneAddict

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Nice packing job on that XL... I did not think mikhail could get that much in
 a package that small. Sure looks exactly like the same parts as the unbalanced
 version i have seen with the black gate output caps.
 at least 2 of the resistors in there show changes indicating heat...
 no change in circuit diagram either._

 

Hi. We appreciate your help and comments. Couple of questions:

 Which resistors are showing signs of heat?

 To increase the lifespan, do you think it would help to drill holes in the Sq Wave XL case (bottom, top or both)? 

 Is there damage that is guaranteed to happen over time no matter what because voltages or current is over the rating?

 I am hoping to get my pictures done tonight.


----------



## XXII

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Nice packing job on that XL... I did not think mikhail could get that much in
 a package that small. Sure looks exactly like the same parts as the unbalanced
 version i have seen with the black gate output caps.
 at least 2 of the resistors in there show changes indicating heat...
 no change in circuit diagram either._

 

Thank you Dr. Gilmore for your comments. I suppose if it doesn't kill me or my headphones I will probably stick with it until it craps out. I suppose turning it off will increase it's lifespan?

 One thing about the damage is that initially when I got my sigma22, the voltage rails were accidentally the wrong way round. I realized this in seconds and unplugged everything. Perhaps the damage was caused then. Larry, yours might not exhibit the same damage.


----------



## mrarroyo

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Ok, this is clearly the hammond 266n12 transformer used in exactly
 the same WRONG way as monoboy's unit.

 Telltale signs
 Black and White winding (110v)
 Orange and Brown winding (110v)
 Red and Blue winding (6.3v)
 Grey and Yellow winding (6.3v)

 mrarroyo's transformer is clearly one of the hammond 300 series
 likely the 378x.

 Telltale signs
 Red, Violet, Red/yellow, red high voltage winding
 yellow, yellow/black, yellow winding (5V not used)
 green, green/yellow, green (6.3 VAC)
 Brown, Brown/yellow, Blue/yellow, Blue (one of the 2 primary windings)
 White, White/black, Black/red, Black (other primary winding)_

 

So to recap I will install the 100K 1W resistor across the caps and open up the unit to verify the transformer I have. 

 If it is a 378x then I am ok, correct?


----------



## kevin gilmore

Quote:


  Originally Posted by *mrarroyo* /img/forum/go_quote.gif 
_So to recap I will install the 100K 1W resistor across the caps and open up the unit to verify the transformer I have. 

 If it is a 378x then I am ok, correct?_

 

If it is a 378x then you are fine. Would probably go 150K 1 Watt just
 in case the voltage is a bit high.


----------



## The Monkey

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_
 OK, real numbers from skylab's unit whose transformer is sinking slowly into the west.

 transformer on for about 5 minutes. After that the voltage starts to sink.
 With 117 VAC input...

 DC filament voltage measured at the tubes 5.11 VDC
 Plate voltage measured at the tubes 97 VDC
 Cathode voltage at the tubes 47 VDC

 My repaired unit with the electraprint transformer
 DC filament 6.2 VDC
 Plate voltage 149 VDC
 Cathode voltage at the tubes 72 VDC

 So its real easy to determine how much trouble your particular unit is in.
 Just measure the filament voltage._

 

KG, or anyone else, could you explain in layman's terms what is being shown by the data above?


----------



## HeadphoneAddict

Quote:


  Originally Posted by *XXII* /img/forum/go_quote.gif 
_Thank you Dr. Gilmore for your comments. I suppose if it doesn't kill me or my headphones I will probably stick with it until it craps out. I suppose turning it off will increase it's lifespan?

 One thing about the damage is that initially when I got my sigma22, the voltage rails were accidentally the wrong way round. I realized this in seconds and unplugged everything. Perhaps the damage was caused then. Larry, yours might not exhibit the same damage._

 

Thanks, that's good to know. 

 I have a 12v Sigma 11 powering my Apogee mini-DAC, and I bought a 24v Sigma 11 from vvs_75 (vladimir) for my Travagans amps or SuperPro DAC707 DAC (works great with Grahm Slee NOVO as well). 

 I don't really use the Sigma 11 much now that I use my Pico DAC-only more than the SuperPro DAC, and I use a Travagans Black to power the Travagans. So, if I knew enough about these things I would try to convert the spare 24v Sigma 11 into one that had the right wiring and voltage for the Sq Wave XL. Last thing I want to do is damage it when it still works very well as a bedroom amp that doesn't need warm-up (power is on all the time with no power switch).


----------



## nurxhunter

Thanks Kevin for data. A+ for sharing B+.

 160W. 'What' is that ringing I hear all the time? It's distortion free, though.


----------



## n_maher

Quote:


  Originally Posted by *The Monkey* /img/forum/go_quote.gif 
_KG, or anyone else, could you explain in layman's terms what is being shown by the data above?_

 

The transformer is sagging, badly, as a result of being severely overloaded.


----------



## n_maher

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_and max power is a B+ of 230 and a current of 220 ma
 For a grand total of 160 watts._

 

FWIW the Menace runs a B+ of 275 with 160mA of current. 
	

	
	
		
		

		
			





 That's right in the ballpark of what the original Wheatfield HA-2 ran as well. And yes, it does make quite a nice space heater and the power trafo require to do that would crush the Extreme chassis.


----------



## nurxhunter

The tech pro I gave the amp to at closing managed to look at it in the evening. Not much detail, his response is below.

 If someone can recommend an alternate to the Edcor that would be appreciated. I am partial to black over blue, unless the entire body is also painted blue, such as the color of SP owners? Actually, this is not so big a deal--and kudos to all who got our attention with hyperbole of explosions and electrocutions--the approach worked. Thanks++

 It's odd that the Extreme has THE BEST bass I have heard on a headphone amp--yet--it is underpowered? Big Solen cap, killer casework--but with chintzed out transformer?? 

 I felt that if Extreme has one failing, it is that, like the other SP amps I have owned, it has a slight 'veil', and seems tipped down to lower frequencies. I thought this due to OTL design vs. OPT designs, the latter which seem to have more 'attack' (but tend to be hummers ). Maybe it the PT on Extreme being underpowered makes it so to my ears. After all, NO ONE likes an under-endowed tranny.

 If someone can recommend an reasonable alternate to the Edcor that would be appreciated. Blue--huh?

 From the Tech Pro:

 "Yes, I see that this transformer is marginal and should be replaced.

 The problem is that the replacement is 6.25 lbs. vs. 1 lb on the original.

 On an episode of The Munsters, Herman needed to take an IQ test for a job interview where he proceeded to place a square peg in a round hole and vice- versa. I can do the same- make this fit but it will stick out like a sore thumb (and be blue colored). Maybe I can find an alternate that will fit better."


----------



## HeadphoneAddict

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_
 From the Tech Pro:

 "Yes, I see that this transformer is marginal and should be replaced.

 The problem is that the replacement is 6.25 lbs. vs. 1 lb on the original.

 On an episode of The Munsters, Herman needed to take an IQ test for a job interview where he proceeded to place a square peg in a round hole and vice- versa. I can do the same- make this fit but it will stick out like a sore thumb (and be blue colored). Maybe I can find an alternate that will fit better."_

 

I loved your tech's response!


----------



## kevin gilmore

If a moderator can split off everything "NON EXTREME" from this thread
 and put it in another thread it will help me to keep better track of who
 owns what.


----------



## Bolder

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_The tech pro I gave the amp to at closing managed to look at it in the evening. Not much detail, his response is below.

 If someone can recommend an alternate to the Edcor that would be appreciated. I am partial to black over blue, unless the entire body is also painted blue, such as the color of SP owners? Actually, this is not so big a deal--and kudos to all who got our attention with hyperbole of explosions and electrocutions--the approach worked. Thanks++_

 

Edcor is a custom house. Everything is made when ordered. If you take the time to talk to the people there, they can paint the bells any color you want. It may take a bit longer, but you will get the colors you want.

 FWIW, I do have one of the EDCOR XPWR039 transformers in the standard color on order. It will be used on a circuit board Extreme. I will post a picture of the unit with new transformer when it is done.

 The Electraprint transformer used in the Extreme Kevin has is an alternative. An even bigger and more expensive alternative. I have also received quotes for a toroidal replacement transformer. Ballpark $80.00-$100.00 depending on quantity ordered and shipping. Lead time 4-6 weeks. Roughly 3.75-3.9" diameter x 1.8" tall.

 You can use two transformers. One for the filaments, which would need to be a good size to handle the current and a smaller one for the high voltage. The transformer used in most of the Extremes is designed to be used as JUST a filament transformer. As it is being used for the high voltage as well, the filament voltage sags, among other problems. You would need to use a LARGER filament transformer, 8-10 amps at least, along with another HV transformer mounted elsewhere.

  Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_It's odd that the Extreme has THE BEST bass I have heard on a headphone amp--yet--it is underpowered? Big Solen cap, killer casework--but with chintzed out transformer?? 

 I felt that if Extreme has one failing, it is that, like the other SP amps I have owned, it has a slight 'veil', and seems tipped down to lower frequencies. I thought this due to OTL design vs. OPT designs, the latter which seem to have more 'attack' (but tend to be hummers ). Maybe it the PT on Extreme being underpowered makes it so to my ears. After all, NO ONE likes an under-endowed tranny._

 


 The 'veil' may be caused by Singlepower's interpretation of OTL design. They used large, polarized electrolytic output coupling caps. These types of caps are designed to be used in power supplies. They are to charge and hold AC power and smooth it to DC. Ways around it are using multiple numbers of smaller values, non-polarized electrolytics, non-polarized film caps and using bypass caps. Bypass caps are smaller values of caps used in parallel to the big caps. Depending on the type and value, they can change the high frequency and possibly help lift the 'veil'. The problems associated with these techniques are very large size and very large cost in comparison to polarized electrolytic capacitors.


----------



## mourip

Quote:


  Originally Posted by *Bolder* /img/forum/go_quote.gif 
_Edcor is a custom house. Everything is made when ordered. If you take the time to talk to the people there, they can paint the bells any color you want. It may take a bit longer, but you will get the colors you want._

 

I spoke to them just now and they said that they only had blue to offer. They also said that it would not be easy for someone to overpaint the bell ends once they were powdercoated. 

 Bummer. They are much cheaper than Jack@Electra-Print transformers. Jack wants $106 or with M6 laminations $150 + $24 shipping. This is for 120V@.5A and 6.3V@10A. The Edcor is 2 x 110V@.25A(=.5A) and 2 x 6.3V@4A(=8A) These come with M6 lams. The Edcor costs $59 + ? shipping. I also emailed Magnequest but I am sure they will be even more expensive than Jack.

 Maybe I am liking blue now


----------



## Bolder

My apologies for the misinformation. I did order transformers from them before and they did offer gray bells. I have heard of others removing the bells and painting them with epoxy based paint.


----------



## mourip

Quote:


  Originally Posted by *Bolder* /img/forum/go_quote.gif 
_My apologies for the misinformation. I did order transformers from them before and they did offer gray bells. I have heard of others removing the bells and painting them with epoxy based paint._

 

Glad to hear about the epoxy paint. Thanks!


----------



## Bolder

Another alternative might be to use a transformer cover. If you have the room, these might work for you. At least they are reasonably priced.


----------



## kevin gilmore

I actually like the look of it with the electraprint transformer. And it is an almost
 exact color copy of the chassis. Not quite the exact same shine.

 If i did not care about the logo on the front (which is a sticker anyway) i would
 strip the whole thing down and take it to a friend in the automotive repair business
 and have the thing painted spies-hecker blacker than black. And then put
 a real clear coat on it.


----------



## Uncle Erik

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_Glad to hear about the epoxy paint. Thanks!_

 

Epoxy over powdercoating won't last. I'd recommend having the housing sandblasted and the powdercoated in black. I believe that the Singlepower chassis are also powdercoated, so that would make a good match.


----------



## mourip

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_I actually like the look of it with the electraprint transformer. And it is an almost
 exact color copy of the chassis. Not quite the exact same shine.

 If i did not care about the logo on the front (which is a sticker anyway) i would
 strip the whole thing down and take it to a friend in the automotive repair business
 and have the thing painted spies-hecker blacker than black. And then put
 a real clear coat on it._

 

I like the Electra-Print look also, traditional and substantial.

 Kevin. Check your PM. I am on a long email exchange with Jack at Electra-print and seem to have run out of expertise. Did not take too long


----------



## nurxhunter

So, could the original transformer be left in and wired properly for use as filament PS @8 A?? Another smaller transformer, installed separately housed or not, could supply plate voltage, as mentioned earlier on site by Boulder?

 Advantage: Leave 'profile' overall lower and lighter. More options for second transformer? Could also be housed. 

 Con: Two transformers?

 Maybe blue is not looking so bad after all, yup? After all, most listen with eyes closed.


----------



## mourip

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_So, could the original transformer be left in and wired properly for use as filament PS @8 A?? Another smaller transformer, installed separately housed or not, could supply plate voltage, as mentioned earlier on site by Boulder?

 Advantage: Leave 'profile' overall lower and lighter. More options for second transformer? Could also be housed. 

 Con: Two transformers?

 Maybe blue is not looking so bad after all, yup? After all, most listen with eyes closed._

 

If you have one of the point to point wired units you might be able to sandwich an HV transformer into the chassis. I have one with the big PCB main board and so have limited internal space. The other thing is that chances are if you have the original Hammond it is already quite stressed and has probably nearly finished it's work on Earth  

 I just pulled the trigger and ordered the Electra-Print. Looks good, no painting, not blue, excellent quality. It is $116 plus shipping but probably way suited for the job. Given the sag that the old one had it is not unlikely to sound better...

 I hope. I hope...


----------



## kevin gilmore

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_So, could the original transformer be left in and wired properly for use as filament PS @8 A?? Another smaller transformer, installed separately housed or not, could supply plate voltage, as mentioned earlier on site by Boulder?

 Advantage: Leave 'profile' overall lower and lighter. More options for second transformer? Could also be housed. 

 Con: Two transformers?

 Maybe blue is not looking so bad after all, yup? After all, most listen with eyes closed._

 

Once the transformer is toast it is already toast and would have to
 be replaced anyway. About $40. But then you have the issue of
 where to put the second transformer. Another box with a neutrik connector.
 yep mikhail did that. Pretty goofy too.
 A single new transformer is much less of a hack job. This thing screams
 for a 150 watt transformer...

  Quote:


 Kevin. Check your PM. I am on a long email exchange with Jack at Electra-print and seem to have run out of expertise. Did not take too long  
 

See jack is trying to make sense out of mikhail's schematics and trying to compare it to old stuff that 
 was done correctly OLD STYLE. That is an impossible task.


----------



## mourip

Quote:


  Originally Posted by *Bolder* /img/forum/go_quote.gif 
_My apologies for the misinformation. I did order transformers from them before and they did offer gray bells. I have heard of others removing the bells and painting them with epoxy based paint._

 

From Jack at Electra-Print"

 "Paul,

 This is another Makhail's design, I have been inundated with transformers burning out for this horrid design. i suggest you completly rebuild it.
 Contact boldercable@comcast.com his name is Wayne, he is rebuilding the same one which went up in smoke or something. he seems to know whats going on with this thing.
 We will not build any transformer for this circuit until it is safely constructed and we approve of the new circuit.
 Ours will burn up too! why waste the money?
 Let us know,

 Jack Elliano
 Electra-Print Audio
 www.electra-print.com"

 I am actually having trouble getting Jack at Electra-Print to sell me a transformer now. He evidently would sell me a transformer if I was scratch building a new amp regardless of my skills but now suggests that I contact you to do the work. I am starting to feel uncomfortable. It is a bit vexing for him to decide who is cabable or not of installing his products without even knowing what the persons skills are. I went ahead and put in an order last night before I saw this email so we will see what happens.

 Wayne. It would seem appropriate that you contact the moderator and have your posts identified as being a member of the trade. I am glad that you are weighing in here as I am aware of your long term, well regarded experience with modifications but it would seem best that everyone know where you stand. Just to be clear, I am sure that Jack is recommending you based upon your experience and your familiarity with the problem.

 Best,

 Paul


----------



## Skylab

Good grief. So now the best option to get transformers for the Extreme isn't even going to be an option???? 

 Sheesh.


----------



## kevin gilmore

No the electraprint won't burn up as i have run the thing for 8 hours straight
 and it is just barely warm.

 But jack is right in OH so many ways about the original design. First the filament
 current peaks out of the transformer really are in the 32 amp range because of
 limited charging of the filament caps. (another well known vendor had this same
 exact problem a bunch of years ago). So you are definitely stressing the diode
 bridge which is getting warm and so on and so on. This is not how to do low
 voltage DC filaments. A better way would be to go with a higher voltage, bring
 the unreg DC up to 8 or 9 volts, then use a 5 amp linear regulator for each tube.
 An even better way is to use a 10 amp high frequency switcher, but some people
 don't like to do that because of possible interference generated from it.

 You can run the filaments with AC voltage. But then there are significant modifications
 to the circuit board necessary, everything has to come out of the box... Lots of
 work. This is what nate maher did with his menace.

 This is one of the many reasons i'm reluctant to work on these things.


----------



## The Monkey

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_It is a bit vexing for him to decide who is cabable or not of installing his products without even knowing what the persons skills are._

 

I think what he's really deciding is that he doesn't want to knowingly sell a product as a drop in replacement into a flawed and possibly dangerous design--regardless of the skill set of the installer. Risk/reward not necessarily in his favor here from a business standpoint.


----------



## Bolder

Paul,

 I have sent E-mails to Jude, but I have yet to hear back from him.

 I will not post again here until I am contacted. Sorry if I violated any of the rules. I was only trying to help.


----------



## Happy Camper

Have the Plitron transformers used in the Platinum version been considered for a replacement?


----------



## kevin gilmore

Quote:


  Originally Posted by *Happy Camper* /img/forum/go_quote.gif 
_Have the Plitron transformers used in the Platinum version been considered for a replacement?_

 

which plitron transformer? Don't remember a picture or any info
 on that particular transformer.


----------



## mourip

Quote:


  Originally Posted by *Bolder* /img/forum/go_quote.gif 
_Paul,

 I have sent E-mails to Jude, but I have yet to hear back from him.

 I will not post again here until I am contacted. Sorry if I violated any of the rules. I was only trying to help._

 

Your help and input are appreciated. I hope that you will continue to post...


----------



## nurxhunter

It's like a Seinfeld episode.....SinglePower banned from Electraprint.

 We will need to get 'ringers' to by the stuff.

 I'll say, it's EXTREME all right.


----------



## mourip

Quote:


  Originally Posted by *The Monkey* /img/forum/go_quote.gif 
_I think what he's really deciding is that he doesn't want to knowingly sell a product as a drop in replacement into a flawed and possibly dangerous design--regardless of the skill set of the installer. Risk/reward not necessarily in his favor here from a business standpoint._

 

I also believe that is his motivation but since he does a brisk business to DIYers it is a bit confusing. Modders and DIYers always work with some amount of risk. If I fried a new transformer by doing a replacement it would never cross my mind to blame the transformer.

 The thing that makes all of this tough is that even though SP gave the Extreme a unique model name it seems as if each one was different. It is almost as if Mikhail built each one with parts on hand. He really was operating as a DIYer.

 I am liking Blue again...


----------



## mourip

From Jack just now...

 "OK, this trans shipping costs is $25.00.
 Send $141.00 paypal to our email address.
 We will have that shipped within one week from payment date.

 As for the circuit you sent me, we viewed it and recongnized the format as 
 the one from Wayne, this used 500+ volt power supply with series caps and 
 the chicken wiring. The chassis and tube arrangement was the same, so we 
 thought it was this HV version and did not print it out assuming it was the 
 same. it appears that he build a few versions on the same chassis's."

 I had sent him the schematic that Kevin posted. Evidently he confused it with a higher voltage version. I ordered the power transformer for 120v @ 500ma, 6.3v @ 10a plus 12" leads to give me some wiggle room in the chassis.

 Caveat emptor 

 Whew!


----------



## kevin gilmore

See this is why the extremes have to be split off from the rest of the stuff.
 2 different schematics. The problem is that a mpx3 extreme and a ppx3 extreme
 don't look like extreme extremes unless you look close.

 The high voltage mpx circuit scares me too.


----------



## HeadphoneAddict

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_No the electraprint won't burn up as i have run the thing for 8 hours straight
 and it is just barely warm.

 But jack is right in OH so many ways about the original design. First the filament
 current peaks out of the transformer really are in the 32 amp range because of
 limited charging of the filament caps. (another well known vendor had this same
 exact problem a bunch of years ago). So you are definitely stressing the diode
 bridge which is getting warm and so on and so on. This is not how to do low
 voltage DC filaments. A better way would be to go with a higher voltage, bring
 the unreg DC up to 8 or 9 volts, then use a 5 amp linear regulator for each tube.
 An even better way is to use a 10 amp high frequency switcher, but some people
 don't like to do that because of possible interference generated from it.

 You can run the filaments with AC voltage. But then there are significant modifications
 to the circuit board necessary, everything has to come out of the box... Lots of
 work. *This is what nate maher did with his menace.*

 This is one of the many reasons i'm reluctant to work on these things._

 

Which is now TKAM's Menace, lucky bastage


----------



## n_maher

Quote:


  Originally Posted by *Bolder* /img/forum/go_quote.gif 
_Paul,

 I have sent E-mails to Jude, but I have yet to hear back from him.

 I will not post again here until I am contacted. Sorry if I violated any of the rules. I was only trying to help._

 

Hi there Wayne (at least I think it's Wayne). I don't believe that your contributions to this thread are in violation of the rules here so please don't feel the need to stop posting. As long as your posts are in compliance with the rules/TOS (see link at bottom of page) you don't need to wait for the MOT tag to be applied to your account. At least not in my opinion.


----------



## Bolder

Thank you, Nate.

 It is Wayne.

 I have just been notified that the EDCOR transformer I ordered two weeks ago has shipped. It should arrive on Friday. I'll take some pictures of it to post here so everyone can make up their own mind as to how it looks compared to the "stock" transformer.

 I do not think I will have the time to mount it on the chassis. I will be out of town next week starting Monday.


----------



## The Monkey

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_I also believe that is his motivation but since he does a brisk business to DIYers it is a bit confusing. Modders and DIYers always work with some amount of risk. If I fried a new transformer by doing a replacement it would never cross my mind to blame the transformer._

 

The difference here is that he now _knows_ the specific risk. Further, I doubt it's the repairer he's worried about, but rather the downstream or subsequent owner.


----------



## mrarroyo

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_If it is a 378x then you are fine. Would probably go 150K 1 Watt just
 in case the voltage is a bit high._

 

I will try to open the unit tomorrow or Saturday and post my findings. I will re-order the resistors to 150K 1 watt. Thanks.


----------



## mrarroyo

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_If it is a 378x then you are fine. Would probably go 150K 1 Watt just
 in case the voltage is a bit high._

 

 Quote:


  Originally Posted by *mrarroyo* /img/forum/go_quote.gif 
_I will try to open the unit tomorrow or Saturday and post my findings. I will re-order the resistors to 150K 1 watt. Thanks._

 

Ok, after an agonizing 30 minutes I was able to remove the transformer cap an I found a Hammond 372BX ( Hammond Mfg. - Universal Primary - "Classic" Power Transformers ). I also installed a pair of 100K 1W resistors across the power caps, will place an order for 150K 1W resistors as was later suggested. Here are a couple of pictures.











 Dr. Gilmore, should I replace the transformer? My favorite tube combinations are a 5670 driving a pair of 6BL7 or a 6SN7 driving a pair of 5687.

 Thanks.


----------



## Bolder

I received the Edcor transformer today.

 The bells ARE very blue.

 Here is a shot of it next to the transformer it is going to replace.






 Here is another picture of it turned 90 degrees.






 This particular Extreme is a circuit board model with the "upgraded" 12 amp transformer. The Edcor should fit fine under the transformer cover. For those that have the smaller transformer, it won't fit inside the cover.


----------



## Bolder

Nice job, Miguel.

 The diodes directly under the power switch look like they have been getting warm. The circuit board is discolored under them. I suggest you may want to check their rating and maybe replace them with higher current and voltage HexFREDs.

 Two 6BL7 want 3 amps. Add in the driver tube and you are pulling above the rated current for your transformer. That may be why the filament diodes are discoloring the board. I would say that you should be using a transformer that allows more current to the filaments.

 BE CAREFUL! There is voltage in excess of 300 volts that chassis.


----------



## kevin gilmore

Yep that is blue alright. Probably glows in the dark too.
 It just might fit in there on the same mounting holes, hard
 to tell.


 On miguels unit,

 I love that white wire in the middle hooked to nothing...

 The resistors across the caps are exactly the idea.

 This is a brighter picture than i have seen before, and the filament
 diodes are definitely getting hot enough to damage the circuit board.
 These probably should be replaced with 10 amp diodes, or better yet
 a 20+ amp diode bridge mounted to the back wall. Problem might be 
 that there is not enough room between the fet and the iec input plug
 to do that. If you mount it on the front the green wires may not be
 long enough to reach, and would have to be extended. The transformer
 is definitely running over spec, but not grossly overspec, so who knows
 how long it will last. 

 The picture by frihed89 in the other thread is the minimum size diodes
 you should be using. Not exactly sure of the part number. Also it might
 be very hard to replace them without removing the circuit board so
 the diode bridge wired into the top might be a better idea.

 equivalent transformers with more filament current would be
 372 dx 4 amps
 372 fx 5 amps
 372 hx 6 amps
 372 jx 8 amps

 Trouble is all of them are sizes bigger than the one that is in there so
 you would have to drill and tap holes to mount them. 

 i would probably go with the 372 hx

 with mikhail it seems it is never easy... 
	

	
	
		
		

		
		
	


	



 quickest long lasting fix is to just change out the diodes
 and hope for the best, and when the transformer finally does
 cause a problem, swap it out.

 with the resistors across the caps the thing should be
 safe to touch after about 30 minutes, but as always it
 is much easier to measure with a voltmeter first.

 With the unit powered, there is about 400 volts across the
 big caps, and about 300 volts across the big solen cap.


----------



## mrarroyo

Quote:


  Originally Posted by *Bolder* /img/forum/go_quote.gif 
_Nice job, Miguel.

 The diodes directly under the power switch look like they have been getting warm. The circuit board is discolored under them. I suggest you may want to check their rating and maybe replace them with higher current and voltage HexFREDs.

 Two 6BL7 want 3 amps. Add in the driver tube and you are pulling above the rated current for your transformer. That may be why the filament diodes are discoloring the board. I would say that you should be using a transformer that allows more current to the filaments.

 BE CAREFUL! There is voltage in excess of 300 volts that chassis._

 

 Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_ ...


 On miguels unit,

 I love that white wire in the middle hooked to nothing...

 The resistors across the caps are exactly the idea.

 This is a brighter picture than i have seen before, and the filament
 diodes are definitely getting hot enough to damage the circuit board.
 These probably should be replaced with 10 amp diodes, or better yet
 a 20+ amp diode bridge mounted to the back wall. Problem might be 
 that there is not enough room between the fet and the iec input plug
 to do that. If you mount it on the front the green wires may not be
 long enough to reach, and would have to be extended. The transformer
 is definitely running over spec, but not grossly overspec, so who knows
 how long it will last. 

 ..._

 

Thanks for the feedback guys, I do not know if it makes any difference but I do not go past 8 clicks on the sttepped attenuator (10 o'clock) and only w/ the K501. With the rest of my cans I do not go past 6 clicks (9 o'clock). BTW, when you indicate I should upgrade the diodes do you mean:

Digi-Key - VS-HFA25PB60PBF-ND (Vishay/Semiconductors - VS-HFA25PB60PBF)

 If ok to use these diodes will they be easy to mount on the same holes? How about orientation? Thanks, and sorry for all the newbie questions.


----------



## kevin gilmore

Electrically those diodes are great. Physically you are going to have
 some trouble with them as they are only are a little less than .5 inch mountings.
 You can measure the ones you have, they sure look like .8 to 1.0 inch mountings.
 And you definitely have to get all 4 of them in the proper orientation. The bands
 on the old diodes indicate the cathode.

 Volume has absolutely nothing to do with power draw. Blast away at 110 db and
 the power difference is unmeasurable.

 From the picture it sure seems that all 4 diodes point the same direction 
 so orientation should be easy.


----------



## mrarroyo

I wonder if I could bend one of the legs and solder a jumper to attach that end to the board while the other end is soldered to the board. What do you think?

 If anyone has four diodes for sale please let me know. Thanks.


----------



## kevin gilmore

this is all i have come up with so far...
625-FES16DT-E3

 and you will definitely have to bend the pins creatively to get it to fit.
 most of the rest of what i have found that is better is either not in stock or
 200 piece or more minimum quantity.

 Getting very hard to do decent diy design work when none of the parts are
 available.


----------



## John D.

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_which plitron transformer? Don't remember a picture or any info
 on that particular transformer._

 

Like Happy Camper, I was also wondering about the plitron transformer for replacemnt on the standard Extreme.
 Here's a link with pictures of the plitron.

Singlepower Extreme Platinum - Impressions - SGHeadphones


----------



## spritzer

It could be any of the smaller units in this lineup but to be sure we'd have to see the sticker on the bottom of the transformer.


----------



## glitch39

since we have the schematic, wouldn't it be easier and safer to build an Extreme from the ground up while using proper values for the components? The two most expensive parts - trafo and caps - will need replacing anyway if we are to save an existing Extreme amp. 

 I like the sound of the Extreme. Just don't want to put a round peg into a square hole. So I'm thinking build one using a newer chassis and wire things better - 90-deg P2P wiring, no cold solder, etc.


----------



## jsaliga

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_I love that white wire in the middle hooked to nothing..._

 

I'm guessing this was actually for a future upgrade, TBD. You send him another $1,000 and he connects the white wire to _something_. 
	

	
	
		
		

		
			





 --Jerome


----------



## shellylh

Quote:


  Originally Posted by *jsaliga* /img/forum/go_quote.gif 
_I'm guessing this was actually for a future upgrade, TBD. You send him another $1,000 and he connects the white wire to something. 
	

	
	
		
		

		
		
	


	




 --Jerome_


----------



## Gvvt

There aren't many laughs in this situation, but jsaliga, your post is one of the funniest things I've seen recently. I wonder if there are testimonials to value of that upgrade.


----------



## shellylh

Quote:


  Originally Posted by *Gvvt* /img/forum/go_quote.gif 
_There aren't many laughs in this situation, but jsaliga, your post is one of the funniest things I've seen recently. I wonder if there are testimonials to value of that upgrade._

 

Yes, you are right... it is not funny... but laughter eases the pain and as someone (one of the *many*) who was hurt, at least financially, though not nearly as much as others, by Mikhail's selfishness, it is all I have left.


----------



## jsaliga

I've actually been debating posting that ever since I saw Kevin's comment about the white wire. It was the first thing that came to mind...and I can even imagine that if you looked at 10 different Singlepower amps with the white wire upgrade they would all be connected to something different. 
	

	
	
		
		

		
		
	


	




 While my post was meant to inject a little bit of humor at Mikhail's expense into a terrible situation for so many of my fellow head-fiers, part of it also reflects my complete and total contempt for the man. And this all makes me wonder whether or not there were people who paid him good money for upgrades, in which he did nothing to their amps, took their money, and sent them back just as they came to him. I don't know that this has happened, but it would not surprise me one bit to learn that it has.

 If anyone thinks my post was in poor taste then please ask a moderator to delete it. I won't object.

 --Jerome


----------



## spritzer

Quote:


  Originally Posted by *jsaliga* /img/forum/go_quote.gif 
_While my post was meant to inject a little bit of humor at Mikhail's expense into a terrible situation for so many of my fellow head-fiers, part of it also reflects my complete and total contempt for the man. And this all makes me wonder whether or not there were people who paid him good money for upgrades, in which he did nothing to their amps, took their money, and sent them back just as they came to him. I don't know that this has happened, but it would not surprise me one bit to learn that it has._

 

There are a few confirmed cases of this plus upgrades being paid for but never installed. My ES-1 is one of latter where almost none of the upgrades even made it into the amp. Some of the "upgrades" were also just a figment of Mikhail's imagination since they didn't apply to that circuit (or any circuit for that matter). He even charged extra for the double umbilical cables when the amp will not function with only one. 

 Another scary thing were amps sent in for service and returning after months with nothing done to them or even harvested for parts for some other amps. He was also keen to charge for "upgrades" when amps were sent in for service which were completely bogus and the amps were still broken when they were sent back. Just see the horrible story of the SS-1 aka. The Wallwart amp.


----------



## jsaliga

I knew about the wall warts. But sometimes it is a challenge to keep up with the ever-evolving Singlepower travesty, and sadly, nothing you have said here surprises me at all. I feel for the many people who got taken to the cleaners by Mikhail.

 --Jerome


----------



## kevin gilmore

So i was nice enough to offer moonboy the services of nate maher who was stupid
 enough to accept. So nate was nice enough to offer skylab my services and i was
 stupid enough to accept. OK, i'm done with this 
	

	
	
		
		

		
		
	


	




 So skylab's replacement transformer showed up today.
 And it was time to remove the old one. Now i know for a fact
 that mikhail has a NC controlled vertical mill and is capable of
 making nice holes in things.

http://gilmore.chem.northwestern.edu/skylab-12.jpg
 The 4 hex head stainless steel screws are the new mounting
 screws, drilled and taped on my personal mill in my basement.
 I really like all the file and scratch marks...

 finished unit
http://gilmore.chem.northwestern.edu/skylab-13.jpg

 now the filter resistors had to go because once the transformer
 was up to spec, there is 7 volts across 50 ohms, thats roughly
 a watt that was being dissipated previously by two .25 watt resistors
 in parallel. (which is why they were cracked and brown) so the
 new resistors
http://gilmore.chem.northwestern.edu/skylab-14.jpg

 So i start the mandatory 2000 hour listening/burnin test. And low and behold
 there is an intermittent buzz in one channel. Turns out one of the ground
 wires on the pot was never soldered to the circuit board, but in playing with
 the pot, the knob came off because mikhail cut the shaft too short and the
 knob was barely holding on.
http://gilmore.chem.northwestern.edu/skylab-15.jpg

 how about that quality grinding job on the pot after cutting it off too short.

 All of this is the most simple of stuff and he could not even get that right.

 The CBS hytrons are definitely sweet sounding with the tungsol gain tube.


----------



## Skylab

I am very grateful to Dr. Gilmore for fixing my Extreme up (and to Nate for coercing him into it 
	

	
	
		
		

		
		
	


	




 ) He went way above and beyond for me.

 It's amazing how bad things were in my amp, given that it seemed to be working OK. I was very close to having a very bad problem.


----------



## mrarroyo

Congratulations and major kudos go to Dr Gilmore and Nate, both did go out of their way to help a couple of head fiers. I believe your amps should sound amazing after all the TLC they have received.


----------



## The Monkey

^Agreed, and actually both have gone out of their way to help many head-fiers over the years.


----------



## mourip

Hi,

 Received my transformer from Electra-Print today and installed it with the help of a buddy who has a drill press and some nice metal working tools. I positioned the transformer to cover the holes and make use of the existing wire holes. I was actually able to cover or use every hole. All we had to do was expand the existing wire holes a bit and drill a couple more. I sorta like the angle of the tranny as it goes along with the tubes. Next I will wire it up and replace the filament rectifier with a 25 amp one.

 I believe that my unit runs at 140v and so all of the caps seem to be adequately spec'd. I may put a bleeder resistor across the big PP cap in the HV supply.

 Kevin. What is the value of those wire wound resistors that drop the filament back to ~6.3v?

 So far, so good...

 Perhaps we should rename this thread "Extreme Make-over." 
	

	
	
		
		

		
		
	


	




 Thanks to Kevin and Nate for helping us along.

 Best,

 Paul


----------



## The Monkey

I think that actually looks pretty cool.


----------



## n_maher

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_So i was nice enough to offer moonboy the services of nate maher who was stupid
 enough to accept. So nate was nice enough to offer skylab my services and i was
 stupid enough to accept. OK, i'm done with this 
	

	
	
		
		

		
			



_

 

Instant Karma's gonna get you Kevin. 
	

	
	
		
		

		
		
	


	




 Glad to hear that another Extreme is now ready to live a healthy, happy life.


----------



## Skylab

Quote:


  Originally Posted by *The Monkey* /img/forum/go_quote.gif 
_I think that actually looks pretty cool._

 

Me too! I think the Eletra-print transformers look nice on the Extreme. And they have the added advantage of working right


----------



## mrarroyo

Nice work there Paul, hope to see the rest of your journey in pictures. Good luck.


----------



## n_maher

Quote:


  Originally Posted by *The Monkey* /img/forum/go_quote.gif 
_I think that actually looks pretty cool._

 

I agree. In the end I do somewhat marvel at what the "real" transformer looks like when it's large enough to supply the power required.

 I read, and I think once even saw, a balanced Extreme. I wish I knew who the owner was, that amp has to be in seriously bad shape.


----------



## h.rav

Wow, it looks a lot better now.


----------



## Happy Camper

Wasn't it markmaxx? He has a Supra Extreme XLR.


----------



## kevin gilmore

Quote:


  Originally Posted by *mourip* /img/forum/go_quote.gif 
_Kevin. What is the value of those wire wound resistors that drop the filament back to ~6.3v?_

 

Depends on the individual unit, the size of the wires from the diode
 bridge, the diode bridge itself... Anywhere from 0 to .15 ohms.

 Measure first. Probably ok at 0.

 Measure at the tubes!

 3 down, just 400 more to go...


----------



## mourip

Quote:


  Originally Posted by *mrarroyo* /img/forum/go_quote.gif 
_Nice work there Paul, hope to see the rest of your journey in pictures. Good luck._

 

Thanks. It was tricky doing all of that drilling and grinding over that powercoat black finish. I had to mother it along while my patient friend did his work. Luckily it turned out well...


----------



## mourip

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Depends on the individual unit, the size of the wires from the diode
 bridge, the diode bridge itself... Anywhere from 0 to .15 ohms.

 Measure first. Probably ok at 0.

 Measure at the tubes!

 3 down, just 400 more to go... 
	

	
	
		
		

		
		
	


	


_

 

Thanks Kevin. I will wire it up and see what I get and then tweak from there. I have a pretty good stash of old low value wirewound resistors to draw from...


----------



## nurxhunter

I went a different route. 





 hammond/182e117/toroidal-transformer


 The original Hamond transformer bobbin tranny did not show stress, according to tech. Since it was designed as a filament transformer, we decided to leave it be and supply only the filaments properly wired with it and to find a torroid that fits internally in the case to supply independent plate voltage. I was able to find a deal on the Hammond over 1/2 the price of catalog, so I thought what the heck--let's give it a try. I opted not to go blue, as well.

 The torroid is 3.0" diameter, 1.6" tall. It fits in the Extreme case. The pics show it wired properly.

 The data show 6.3V from Hammond and 180V out of the torroid. The external form factor is unchanged, only a single smallish bolt holds the torroid to case bottom, not visible unless unit is upside down.

 Well, I turned it on and plugged in the the neural net distortion meter, cochlea-driven, pinna-modulated, HD600/cardas aided. RCA 6AS7G and WE 396A (ECC1 adapter). FYI.

 The preponderant bass is gone, the unit is more transparent sounding, better balance. Still great bass, just not a 'tipped-down' sound anymore. Maybe I was hearing a bit of sag before--though it was not bad, just better now TME. 

 Notable is that the tranny case is now only warmish to touch. I estimate now 110 deg F, which is cool, I think. Before, it passed the the manly pinky test, now it could pass the Hot Lips Hoolihan test.

 Listening volume out of Zapped Zahlou DAC into amp is 9 o'clock. Tube hiss sets in at 1-ish. ZERO HUM all the way up the dial, just like before. So it's true what they say about torroids not humming, I suppose.

 What I call the OTL character (or others may believe it is the large cap character) is still there, and this is not bad, just different than some of the OT amps I own, like my favorites pictured below. I still own my Ear Max Pro, btw, still smitten by the warm clarity and goodness of prime hot gl-ass with pinched waists from Germany and Holland. Talk about cool running and tiny triode footprint. A classic.

 The OTL amps I have owned are more fatigue free on over-extended loudish (85 db or so, db-A weighted, peak captured) listening, I have noted.

 The extreme sounded great before, it sounds better now. I kept the external form factor, which I wanted to do, and I saved some bucks, which I also desired. I have seven or so tubed headamps (having sold around six others), and not all can live under one roof this coming (cold) winter, due to some changes I fear are coming. On the other hand, seven tube amps might be comfy on some days, when wolves start to howl. The problem is, each time I listen to these gals, I fall in love all over again with each. Clearly, I gots to get a life, and sell an amp or two. I may need to take extreme steps.

 That's my story for now. 

 Thanks Kevin, Rob, Paul, Skylab, et al., for the great guidance. I found this particular thread the best I have experienced anywhere due to the above truly SUPREME, and not extreme, headfilies.

 I'll listen for a bit more, let it run in overnight and tomorrow, and if all is well, I will post tech contact info. Might be useful to have a pro tech when needed.

 P.L.H.











[/IMG]


----------



## guzziguy

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_<snip>

 Now i know for a fact
 that mikhail has a NC controlled vertical mill and is capable of
 making nice holes in things._

 

He probably had to sell it along the way.

  Quote:


 http://gilmore.chem.northwestern.edu/skylab-12.jpg
 The 4 hex head stainless steel screws are the new mounting
 screws, drilled and taped on my personal mill in my basement.
 I really like all the file and scratch marks...

 finished unit
http://gilmore.chem.northwestern.edu/skylab-13.jpg 
 

It kills the looks, but it's a lot better to have dead looks than a dead amp.

  Quote:


 <snip>
 how about that quality grinding job on the pot after cutting it off too short.

 All of this is the most simple of stuff and he could not even get that right. 
 

It simply boggles the mind.


----------



## mourip

I wired up the beast last night, adding the 25amp rectifier which gracefully fit into the existing position. When I plugged in the power cord I got a flash ...the 4th of July instead of Christmas!

 The culprit was a solder blob that bridged the hot and neutral AC inlet tabs. One fuse later I had 9v and 170v from each supply without the tubes in place. Hopefully the unloaded filament supply will calm down to 6.3?

 I did not put in tubes or try for music yet as I want to look inside one more time for other soldering blunders before risking my Tungsols.

 Nice going on your amp Nurxhunter!

 The adventure continues...


----------



## nurxhunter

Thanks Paul.

 Oddly, I could not go to sleep with the amp on, the sound was not quite doing it for me. Instead of a 396A, I popped in a CBS 5692 sitting in another amp handy. Bingo, the smooth tube signature I looked for, much better bass, better stage presence for Frank--a richer sounding Frank. Wider orchestra.

 It appears the sound character of the amp has changed with the upgrade, whereas the clearer sound of the 396A before the fix seemed perfect, now, it seems a mite too detailed, and lacking just a touch of bass. With a 6sn7 in place, I liked it quite a bit better. Before the fix, the 6SN7 sounded way to soft for my taste with 6SN7 as driver. Will have fun rolling a bit again.

 Ran all night, transformer cover barely warm. The case does get quite a bit warmer--not hot, though. The tubes get warmer than before the fix, not ultra hot. Before, I could touch their top (6AS7) comfortably, now I cannot. Still, this is a quiet amp--before and now, with plenty of strong,. clean overdrive capability. Impressive.

 Imagination? Preliminary findings.

 If 'real', i winder if the different preferences for the driver from so many SP owners had something to do with different builds. Imagination?


----------



## tkam

You could touch the top of a running 6as7 before? The old transformer must have been sagging a ton and barely providing enough filament current for the tube to function. There is no way a running tube of that size should ever be able to be touched "comfortably"


----------



## Skylab

Quote:


  Originally Posted by *tkam* /img/forum/go_quote.gif 
_You could touch the top of a running 6as7 before? The old transformer must have been sagging a ton and barely providing enough filament current for the tube to function. There is no way a running tube of that size should ever be able to be touched "comfortably"_

 

Indeed! I have a half-dozen amps that use the 6AS7 - if you touch the 6AS7 when the amp is running, you're going to get burned, every time. This is as it should be.


----------



## kevin gilmore

I wasn't going to say much about the difference in sound, but it is very significant.
 Since all i have seen is dead ones (or at least spitting up blood) its hard to know
 what they sounded like before, but skylabs unit before the transformer vs my
 unit, big difference. Way more balls in general.


----------



## Skylab

Quote:


  Originally Posted by *guzziguy* /img/forum/go_quote.gif 
_


 It kills the looks, but it's a lot better to have dead looks than a dead amp.


_

 

I guess I'm a real geek, but I like the look with the bigger transformer. Not sure about the blue transformers, but mine is a nice black one. I won't see it in person until tomorrow, but from the pics, I will have no issue with the looks. And that is totally secondary for me anyway - not only is the amp now going to work safely, it's going to sound BETTER than before. That just rocks.


----------



## n_maher

I'm with you Rob, I'd take that exposed trafo (blue or black) over the little perforated box any day. Although I suppose that's always been obvious given the boat anchors I tend to build. My current build is a forest of exposed iron and huge film caps and I couldn't be happier.


----------



## diego

@nurxhunter

 Most likely the transformer was not able to provide enough voltage for the plate and filaments before. If the plate voltage had a significant change the operating point of the tubes is now different.

 SP advertised it's amplifiers as great for tube rolling but I don't see how this could really work. In my opinion the amps probably ran at good operating points only with a few tubes and the rest ran at suboptimal points. Since the plate voltage was probably different from one amp to the other, that could be one of the reasons why each owner liked different tubes. I'm talking different type of tubes not brands and mostly in the input position.


----------



## Skylab

No doubt about that - Mikhail once told me in an email, where I asked specifically, that I could use an ECC32 as the driver tube. It draws .9a, versus .6 for a 6SN7. Clearly, my Extreme was getting cooked, and I am sure that my use of a ECC32 didn't help, since the amp couldn't even deliver enough current for the two 6AS7G's and a 6SN7...


----------



## diego

I read your review comparing your extreme to a B22 and I agreed with most things but there were some differences. That was probably because my extreme was different because B22s aren't 
	

	
	
		
		

		
			





. I never opened mine though and I sold it a year ago so I'll never know how it was on the inside.


----------



## Skylab

Right - sadly, almost everything I said about the Extreme really isn't valid for any one else's Extreme - and mine wasn't safely built!


----------



## Happy Camper

Tube rolling all over again. Now stop cooking amps and back to the music.


----------



## nurxhunter

Pro Digital Inc
Welcome to Pro Digital Inc. - DAT Recorder Service Specialists
 700 Park Way # B
 Broomall, PA 19008-4211
 (610) 353-2400
 Paul is the man. See the wiring work in the pic I posted on previous page again below.





 I have had Paul put sockets into Cal Alpha DACS for op amp rolling 
 (which I never did--sold all my Cal Audio). His soldering work is amazing. He is a mentch to boot.

 >>>>Is this the place to post techs who can work on an Extreme? If not, can you refer me to the link.

 It was only a few weeks ago I found out all the SP issues, shocking--to the mind that is. The Extreme is worth a little hassle, I feel. Super sounding headamp.

 What, stop rolling and enjoy music itself--whadaya nuts?


----------



## mourip

We got music, good music...

 Held my breath and fired it up with tubes in. Got 6.19v on filaments and 119v on HV. I was a little surprised by how low the HV was but I guess that is what it was spec'd at. I put in a sacrificial Philips 6SN7 just to see if I had bricked it but all is well. I next put in my favorite Bendix 12Au7 to see how it compared to my memory of it. It had not see too much use this last year since I got the Tektron. Now I remember why I got this amp. Boy that tube makes a difference. 

 Sweet, detailed music... it was worth the effort.

 Best,

 Paul


----------



## guzziguy

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_I guess I'm a real geek, but I like the look with the bigger transformer. Not sure about the blue transformers, but mine is a nice black one. I won't see it in person until tomorrow, but from the pics, I will have no issue with the looks. And that is totally secondary for me anyway - not only is the amp now going to work safely, it's going to sound BETTER than before. That just rocks._

 

I don't mind the looks of an exposed transformer, it's just that the size balance among the things on top of the amp is gone and the new, unbalanced look doesn't work for me. I'm not mad about the look of my Platinum Extreme for the same reason, though I think that the covered Plitron works a little better than the exposed transformer.

 I agree wholeheartedly that have a well-built, properly spec'ed, safe amp with better SQ is much more important than looks. But I pretty much said that in my post.

 BTW, if you or anyone else don't like the color of the transformer, there's no reason you can't paint it. Just be sure to protect the wires from the paint. Look at the Bottlehead site for paint ideas.

  Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_I'm with you Rob, I'd take that exposed trafo (blue or black) over the little perforated box any day. Although I suppose that's always been obvious given the boat anchors I tend to build. My current build is a forest of exposed iron and huge film caps and I couldn't be happier._

 

Exposed can be very good. I've always loved the looks of your amps. But then you work hard to get a balanced, clean look.


----------



## nurxhunter

I felt the same, which is why I went the route to source a torroid transformer to fit inside the box. Despite the issues with SP, I look and the black box as a classic design that has had an indelible impact on this space, for variety of reasons. My next choice would have been the Electraprint, but at 4X $$. Had I not gotten a good deal on the Hammond torroid, I might have gone with EP.

 I'm surprised that after the torroid, I highly prefer 6SN7 family (for now), including 6f8G and 5692, which before sounded way to soft. now, the 396A sound glassy. I have a BL63 drawing 1.2A, which sounded awful before, I wonder what it will sound like now.


----------



## n_maher

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_I'm surprised that after the torroid, I highly prefer 6SN7 family (for now), including 6f8G and 5692, which before sounded way to soft. now, the 396A sound glassy. I have a BL63 drawing 1.2A, which sounded awful before, I wonder what it will sound like now._

 

It's not surprising really at all. The B+ and possibly even the filaments were probably sagging badly which not only affected the input but also the output tubes. That poor little filament trafo was just getting smoked by the B+ current I'm sure.


----------



## Skylab

I picked up my resurrected Extreme this morning from Dr. Gilmore. It sounds TERRIFIC - no question that it sounds better than the original - MUCH quieter background, and an overall richer sound. VERY NICE. 

 For those of you on the fence - having it repaired with the right transformer is worth the effort, IMO. I saw the original transformer in person, and it looks BAD - no way anyone should be using a stock Extreme any more. But with the right transformer and a couple of $2 resisters - it's actually an upgrade 
	

	
	
		
		

		
		
	


	




 I'm very grateful to Dr. Gilmore for helping me out.


----------



## HeadphoneAddict

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_I picked up my resurrected Extreme this morning from Dr. Gilmore. It sounds TERRIFIC - no question that it sounds better than the original - MUCH quieter background, and an overall richer sound. VERY NICE. 

 For those of you on the fence - having it repaired with the right transformer is worth the effort, IMO. I saw the original transformer in person, and it looks BAD - no way anyone should be using a stock Extreme any more. But with the right transformer and a couple of $2 resisters - it's actually an upgrade 
	

	
	
		
		

		
		
	


	




 I'm very grateful to Dr. Gilmore for helping me out._

 

That's great news.


----------



## mrarroyo

Glad Dr. Gilmore was able to assist in resurrecting your amp! Enjoy it.


----------



## Bolder

Here is the Edcor transformer mounted on a small chassis Extreme







 Same amp with transformer cover placed over the Edcor.






 This amp also had the HV diodes replaced and film caps added to the output caps.


----------



## Skylab

Very nice! I do not like the look of the electric blue transformer, but it looks fine covered up


----------



## Bolder

Thank for your comments, Skylab.

 I just spoke to the owner of the Extreme after he saw the photos. 

 He actually likes the look. Kinda like the Donald North amps with their bright blue chassis. Beauty is in the eye of the beholder 
	

	
	
		
		

		
		
	


	




 The bridge rectifier for the filaments is bolted the the back of the chassis in this amp. There was no thermal compound used. I added some thermal grease and there was a marked improvement in thermal transfer. 

 The new transformer is rated for 8 amps filament current. I did note that after 1/2 hour driving a pair of HD-600s the tranny was running a little warm. The transformer cover is not fastened down. I will leave it up to the owner if he wants to cover it up. I would suggest the cover be left off for additional cooling.


----------



## Skylab

Indeed - some people will love the blue I'm sure! Most importantly, it's another Extreme in the "safe" column


----------



## Frihed89

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_










[/IMG]



















_

 

That sure looks like a Jeff Larson amp. He's a terrific person, builder and audioexpert. I hope you like it.


----------



## Frihed89

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_Indeed - some people will love the blue I'm sure! Most importantly, it's another Extreme in the "safe" column 
	

	
	
		
		

		
		
	


	


_

 

What were the originals rated at and which ones did you replace them with? Mine are too small, I am pretty sure, even if I ditch the high power option on my MPX3.


----------



## Skylab

The transformer I ordered from Electraprint was as follows:

 $116.00 M19

 Primary: 1 x 115VAC
 Secondaries:
 1 x 115VAC @ .4A
 1 x 6.6VAC @ 8A or 2 x 6.6VAC @ 4A
 Lead Length: Standard
 Mounting Style: Vertical


----------



## guitarplayer

Quote:


  Originally Posted by *Frihed89* /img/forum/go_quote.gif 
_That sure looks like a Jeff Larson amp. He's a terrific person, builder and audioexpert. I hope you like it._

 

Jef makes some really great sounding gear, indeed.

 Lee


----------



## nurxhunter

Yup, from Jeff. I do in fact like it. I posted those pics because these I the amps I can;t seem to let go. Each has its own sound signature, each is 'the best'.

 Back to this thread--the Extreme is my reference amongst these. Before the new internal tranny was implemented to supply the plates, I could touch and hold for a second the 6AS7G tubes--and even Bendix 6080. the Tformer did not get very hot, but quite warm.

 Now with separate transformers for filaments and plates, the 6AS7 are too hot to touch almost (certainly not hold), the transformer runs much cooler supplying only the filaments and properly wired, and the Extreme sounds great, quite a bit more 'extreme' than before ( I liked it even in its weakened state before, much more so now). Certainly, the Extreme is the quietest amp I have ever owned, except for the diminutive and over-acheiving Earmax pro.

 I am surprised the Edcor fit under the cover--I hear nice things about their output transformers--great for the money.


----------



## Skylab

I have five different amps that use the 6AS7G - and on all of them, if you touch the tube when it's been on for more than 10 minutes, you get burned. You should never have been able to touch and hold a 6AS7G on a properly functioning amp.


----------



## Rob N

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_Certainly, the Extreme is the quietest amp I have ever owned, except for the diminutive and over-acheiving Earmax pro._

 

OT I know but the EMP is a great amp.Have you heard the Earmax Anniversary/Silver Edition?


----------



## kevin gilmore

just when you think you have seen everything, comes this extreme built as an
 extreme. At least it was an extreme designed board in a MPX3 chassis.

 Now i knew this one was going to be real trouble when i first saw pictures of it.
 I open the thing, turn it on, no filament power, but the .15 ohm resistor while
 very toasted is still conductive. But it fell right off the circuit board.
http://gilmore.chem.northwestern.edu/raffy4.jpg

 So its obviously time to remove the circuit board.
 But wait, the side board is soldered in from the backside
http://gilmore.chem.northwestern.edu/raffy8.jpg
http://gilmore.chem.northwestern.edu/raffy6.jpg
http://gilmore.chem.northwestern.edu/raffy5.jpg

 and no way to unsolder it without brute force.
 Sweet.

 3 hours later...
http://gilmore.chem.northwestern.edu/raffy1.jpg

 The resistor burned all the way thru the mounting pad on the left.

 but did you notice the soldering job...
 here is a closeup

http://gilmore.chem.northwestern.edu/raffy3.jpg

 globs of solder just barely hanging on the board...

 Finally 20 watts of resistor on ceramic standoff's that
 should live a while.
http://gilmore.chem.northwestern.edu/raffy7.jpg

 OK, further comments, it was obvious by the time this was built that
 lots of the smaller transformers were burning up, so mikhail scaled up
 the transformer. He scaled it up a bunch. 7.5 volts AC before the diode
 bridge under load. So the diode bridge gets even hotter than the previous
 units, and that poor little original 5 watt resistor is running at right around
 10 watts, and still delivering only 5.8 VDC to the tubes.

 my 5 watt x 4 resistors in parallel end up .125 ohm, and generate about
 12 watts of heat.

 Bottom line, every one of the units like this is going to do the same thing.
 While the parts are cheaper, the labor is 4 times that of the other units.

 If you own one of these versions you should open it up and take a look.


----------



## Skylab

YIPES! That is really, really scary.


----------



## shellylh

Holy ****, that is something else. Yikes.


----------



## moonboy403

Dr. Gilmore, is that Extreme in the picture from Nate? If so, I believe Shelly and I were two of those unlucky owners that lived through the edge with it.


----------



## spritzer

It also looks like that resistor cooked every part close to it. The electrolytics for the filament supply have nearly burst...


----------



## Born2bwire

I think the standing operating procedure at this point would be to yank out all the amp innards with a claw hammer and then stuff the shiny casing full of used pinball machine parts.

 I mean, everybody loves pinball.


----------



## n_maher

Quote:


  Originally Posted by *moonboy403* /img/forum/go_quote.gif 
_Dr. Gilmore, is that Extreme in the picture from Nate? If so, I believe Shelly and I were two of those unlucky owners that lived through the edge with it._

 

No, it's yet another shining example of ineptitude unfortunately. Every time I think this can't get worse I'm proven wrong.


----------



## Happy Camper

Singlepower amp model "Extreme", board "Extreme Rev. A/ Feb. 2007" 

 Immediate hazard warning.


----------



## kevin gilmore

http://gilmore.chem.northwestern.edu...ourextreme.pdf

 This is absolutely the first example i have seen where mikhail has biased
 up the filaments.

 If he had done this with the ES1/ES2...

 By the way, on most of the ES1/ES2 with the plitron transformers, there was
 already a 40 volt winding that was abolutely perfect for the C- supply, and
 there were dual filaments... 
	

	
	
		
		

		
		
	


	




 Most of them were cut short and heat shrunk, but a few are long enough to
 actually use...


----------



## immtbiker

Another proud product built by the Singlepower team, "Pursuing excellence at every corner." Quality is Job 1!


----------



## The Monkey

Just imagine what's Job 2...


----------



## atbglenn

Unbelievable


----------



## mrarroyo

Quote:


  Originally Posted by *spritzer* /img/forum/go_quote.gif 
_ ... The electrolytics for the filament supply have nearly burst... 
	

	
	
		
		

		
		
	


	


_

 

I saw that, scary job to say the least. Dr. Gilmore is that raffy's unit?


----------



## 00940

Actually, those threads are very informative for tube amps building safety. Should be stickied in the diy forum


----------



## mikeymad

Thanks Kevin for giving us more things to look out for... 

 Never thought that I would have to know so much EE just to own an amp... 

 Cheers,


----------



## nurxhunter

"So its obviously time to remove the circuit board.
 But wait, the side board is soldered in from the backside

 and no way to unsolder it without brute force.
 Sweet."

 I was puzzled by the side board, which seems to be completely unnecessary. Who uses a side board simply to attach RCAs input to PCB? 

 1) Does this 'side board' serve any purpose some wire would not ? Would seem straightforward to dispense with without undue force or hassle--toss it--and wire the inputs to the board?

 2) All the pics I have seen with resistors in place at position R54 --show two 5W stacked resistors at R54, not one resistor in that position. Was this unit maybe an early one, and then a correction was made in later units.


----------



## kevin gilmore

No useful purpose in the sideboard, other than making it almost impossible to remove.
 Obviously the ground on the backside did not work, hence the extra set of blue
 grounding wires.

 I had to specially machine a tool with .060 sidewalls to fit into the circuit board to
 get to the nuts that hold the tube sockets to the chassis. Without that tool the
 circuit board would never survive unsoldering all of the tube socket pins. This tool
 is not going to last long with sidewalls that thin.

 Notice the 2 big filament electrolytics and the huge holes for screw mount caps.
 Yet the caps installed are not screw mount and are just soldered to the side
 of the holes.

 I've seen many units with 2 filament resistors, some with one, and some with
 none. Still don't understand the first high voltage cap in series with the 15 ohm
 resistor. Does absolutely nothing except waste parts.

 The resistance of the circuit board lands causes a loss of about .4 volts from the
 diode bridge ground to the tube ground. So that is heating up too.


----------



## nurxhunter

Extremely great answers. Thanks.


----------



## kokohore

Hi, 
 I decided to open my Extreme again (the last time I saw the inside was in Nov. 2008)







[/url][/IMG]

 This is the Extreme_IN REV A Feb 2007 version. I think this is stock Extreme except for a stepped attenuator.

 R54 looked like this






[/url][/IMG]

 Two 25ohm 6.5w in parallel

 And I confirmed the trans was 266N12. It looked like this






[/url][/IMG]

 And... what do you guys think, should I replace the R54?
 Also, assuming it a stock Extreme (2007), can I replace the tranny with aforementioned Electraprint or Edcor ones (or possibly addition of Hammond 182e117 toroidal )?
 Thanks


----------



## kevin gilmore

Transformer definitely on its way to complete burnout.
 The two resistors are actually 250 milliohms each.

 When you replace the transformer you will need to adjust the
 resistors to get the voltage to as close to 6.3 VDC as possible.

 The electraprint transformer is actually lightly low so you will end
 up shorting out the 2 resistors.


----------



## FallenAngel

Just wanted to bring my thread up here as I'm working on fixing up my MPX3 in the DIY section. Any help/contribution/advice/suggestions would be greatly appreciated.

http://www.head-fi.org/forums/f6/sin...r-mpx3-444640/

 Thanks


----------



## kokohore

Dr. Gilmore, 
 Thanks for your imput. I will get Electraprint transformer soon.

 Just one more question
  Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_The electraprint transformer is actually lightly low so you will end up shorting out the 2 resistors._

 

By shorting out the 2 resistors, you mean this?
 Sorry for very newbie question 
	

	
	
		
		

		
		
	


	









[/url][/IMG]

 Thanks again


----------



## diego

Yes, but you should install the new transformer first and measure the heater voltage. Then you can figure out what size resistor you need or if you simply need to short it.


----------



## kokohore

Quote:


  Originally Posted by *diego* /img/forum/go_quote.gif 
_Yes, but you should install the new transformer first and measure the heater voltage. Then you can figure out what size resistor you need in there or if you simply need to short it._

 

Thanks, I have just ordered the transformer at Electra-Print.


----------



## minimus

The Singlepower fiasco reminds me of some comments from an audio dealer I know and trust. I asked what he thought of Audio Research stereo power tube amps a while back, and he said that although the amps sound wonderful, every one he ever owned eventually failed in "spectaculur" fashion. That suggests that amps made by well-known amp manufacturers with long histories and good reputations also may have design flaws...maybe not of the magnitued of the Singlepower amps, but enough to require expensive repairs.

 As much as I am annoyed and stunned by Mikhail's ubiquitous fraud, I still am addicted to the Singlepower Extreme. As crappy as the amp's build quality was, it still sounded damn good to me. I have been using my Blue Circle Hat Peed Thingee while the Singlepower amp is in for repair, and I now see how deficient it is relative to the Extreme. Yes, the Blue Circle amp is good, but it just falls short in dynamics and soundstage.vIn any case, I am looking forward to getting my Singlepower amp back and restored to good health. I will post more details on diagnosis and repair costs when the amp is repaired.


----------



## nurxhunter

"I still am addicted to the Singlepower Extreme."

 Me too. I was going to sell mine due to all the huff here--even after I had a dual transformer put in.. Since I have a nice custom DIY job I also love, and times are tight, I listed it on Agon.

 A guy bought it, but I told him to read some of the posts here before paying. He took my advice. He laughed--thought almost all were silly--but--he asked if he could back out. He was worried he could never flip it. I said of course he can back out--I was glad, in retrospect. There was other interest, when I directed them to this site, they all backed out. They did not care that it now had dual transformers, one for the plates, and one for the heaters, or that the interior is pristine, and certified by two techs. Fine by me.

 I am glad I still have it, because its an extraordinary sounding headphone amp, especially once the transformer is uprated, as many have discovered, it then gets even better then before. 

 My 17 YO has listened to all my headphone amps carefully over the past seven years--starting as a tot, he quickly heard the difference between tube and SS. Remarkably, he can discern the EarMax Pro when it has Telefunken E188CC in it and a coin-base 12AT7--every time, even between months intervals. Maybe its genetic; it remains a favorite of his as well. The benefit is that he has no preconceptions. He tells it like he hears it. Usually, he has no idea which amp is playing. In fact, I have two HD600/Cardas phones(for bedroom and office) so I compare amps 'side-by-side' now and then--to 'be sure'. Since I am a big fan of the experimental method, I even have a rat shack SPL meter handy to make sure amplitudes are equal when doing a blinded test.

 He happened to listen to the upgraded Extreme on Friday night and said "Dad, whatever this is, it's the best I have ever heard--except for that big funky one you have there". I asked how did he know this was not that one, which was also on. He said: "I've never heard bass like this before, not even from the big one; is this new"?

 So, from the mouth of babes. However, I made him leave the room--just in case my Extreme explodes like a grenade, or goes up like a fireball, or strikes him with a bolt of electricity, or jumps off the shelf and cracks his skull with its battleship of a case--which in fact--is grenade proof. Just in case, the Extreme remains off limits to little girls and boys, apparently.

 Enjoy your amp when it gets back. Based on what I and others have reported, you will be pleasantly surprised, and you will be hard pressed to find a better sounding SET-OTL headphone amp at any price that can drive any phone. One day, these will be classics--or someone will simply copy the design and sell them, probably for much more than SP did, or they too will go under.

 Thanks to all on this site, especially the Doc, who have offered fair and productive advice, sane recommendations, great guidance and have had great patience with newbies, like myself. As for others, they probably meant well. Maybe--this saga is winding down, or, it could percolate on and on. I think the former.


----------



## thathertz

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_"I still am addicted to the Singlepower Extreme."

 Me too. I was going to sell mine due to all the huff here--even after I had a dual transformer put in.. Since I have a nice custom DIY job I also love, and times are tight, I listed it on Agon.

 A guy bought it, but I told him to read some of the posts here before paying. He took my advice. He laughed--thought almost all were silly--but--he asked if he could back out. He was worried he could never flip it. I said of course he can back out--I was glad, in retrospect. There was other interest, when I directed them to this site, they all backed out. They did not care that it now had dual transformers, one for the plates, and one for the heaters, or that the interior is pristine, and certified by two techs. Fine by me.

 I am glad I still have it, because its an extraordinary sounding headphone amp, especially once the transformer is uprated, as many have discovered, it then gets even better then before. 

 My 17 YO has listened to all my headphone amps carefully over the past seven years--starting as a tot, he quickly heard the difference between tube and SS. Remarkably, he can discern the EarMax Pro when it has Telefunken E188CC in it and a coin-base 12AT7--every time, even between months intervals. Maybe its genetic; it remains a favorite of his as well. The benefit is that he has no preconceptions. He tells it like he hears it. Usually, he has no idea which amp is playing. In fact, I have two HD600/Cardas phones(for bedroom and office) so I compare amps 'side-by-side' now and then--to 'be sure'. Since I am a big fan of the experimental method, I even have a rat shack SPL meter handy to make sure amplitudes are equal when doing a blinded test.

 He happened to listen to the upgraded Extreme on Friday night and said "Dad, whatever this is, it's the best I have ever heard--except for that big funky one you have there". I asked how did he know this was not that one, which was also on. He said: "I've never heard bass like this before, not even from the big one; is this new"?

 So, from the mouth of babes. However, I made him leave the room--just in case my Extreme explodes like a grenade, or goes up like a fireball, or strikes him with a bolt of electricity, or jumps off the shelf and cracks his skull with its battleship of a case--which in fact--is grenade proof. Just in case, the Extreme remains off limits to little girls and boys, apparently.

 Enjoy your amp when it gets back. Based on what I and others have reported, you will be pleasantly surprised, and you will be hard pressed to find a better sounding SET-OTL headphone amp at any price that can drive any phone. One day, these will be classics--or someone will simply copy the design and sell them, probably for much more than SP did, or they too will go under.

 Thanks to all on this site, especially the Doc, who have offered fair and productive advice, sane recommendations, great guidance and have had great patience with newbies, like myself. As for others, they probably meant well. Maybe--this saga is winding down, or, it could percolate on and on. I think the former._

 

I think it's winding down. I'm still waiting for my EE guy to build another 
 transformer for my MPX3. It's been two months now and I've still been
 listening to it every weekend. No explosions, no light show, no lethal
 shock. I've been considering other amps but when listening to my 
 MPX3 in the early hours of Saturday morning..I can't imagine being 
 without it...the sound is just INCREDIBLE.


----------



## eric stern

I would like to weigh in on the Singlepower Extreme amp bandwagon. Yes, they have lost their credibility for customer service and Mikhail is impossible to deal with on just about any level. That being said, my amp was recently modified by a local electrical guru for $300: new transformer and an added filament dropping resistor wired to the bridge rectifier on the rear panel.

 It sounds just as wonderful, and now has better bass. The external transformer is much cooler to touch and the case where the new transformer resides is still quite warm to touch after several hours of playing music. 

 Other manufacturers have equipment that fails and probably after a year or two or three charge $$$ to trouble shoot and repair their gear. And, also charge round trip shipping to you. My advice is to live with the Singlepower Exrteme or find a local repair person and move on with your life and musical enjoyment. The internet is a powerful force in today's world; but it shouldn't make you feel bad about life, or the things you love, including music.


----------



## thathertz

Quote:


  Originally Posted by *eric stern* /img/forum/go_quote.gif 
_I would like to weigh in on the Singlepower Extreme amp bandwagon. Yes, they have lost their credibility for customer service and Mikhail is impossible to deal with on just about any level. That being said, my amp was recently modified by a local electrical guru for $300: new transformer and an added filament dropping resistor wired to the bridge rectifier on the rear panel.

 It sounds just as wonderful, and now has better bass. The external transformer is much cooler to touch and the case where the new transformer resides is still quite warm to touch after several hours of playing music. 

 Other manufacturers have equipment that fails and probably after a year or two or three charge $$$ to trouble shoot and repair their gear. And, also charge round trip shipping to you. My advice is to live with the Singlepower Exrteme or find a local repair person and move on with your life and musical enjoyment. The internet is a powerful force in today's world; but it shouldn't make you feel bad about life, or the things you love, including music._

 

Very well said! 

 I'm still waiting for my MPX3 transformer rebuild but I'm listening to it for
 a few hours each weekend. I've never looked forward to listening to music
 so much. 

 The MPX3 is here to stay.


----------



## The Monkey

Quote:


  Originally Posted by *eric stern* /img/forum/go_quote.gif 
_Yes, they have lost their credibility for customer service and Mikhail is impossible to deal with on just about any level._

 

SinglePower amps can sound good. That's not really in dispute. However, SinglePower has lost its credibility in every way, not just with respect to its customer service.


----------



## nurxhunter

That is my experience exactly, sounds as good, better bass. 

 Same experience, transformer now runs barley warm, before it was rather warm.

 It is worth noting the box is SEALED, virtually. Heat is released through the case metal by radiating, not through convection from vent holes. With temp. in home 5 or so degrees cooler now, the Extreme case also feels cooler. I wish my Music Reference RM9 was as cool as my Extreme. There is no hot spot I can determine; rather, the entire case gets warm. The high-ish power resistors seem to be working, I might speculate, rather than this observation being the harbinger of doom and destruction from explosion, electrocution or conflagration.

 Also consistent with experience--every time anyone says anything positive about an Extreme here, someone pops in and reminds us there were build issues; funny, as if this was not already well established, especially in this thread. Never mind the positive comments are on certified units. It's like there is a posse watching. Yea, Supreme beings are watching ready to smite any happy camper, or remind the forgetful, least we somehow can forget. Once in a blue moon, a picture of a relatively minor issue appears, followed by maybe a half dozen of the faithful chiming OMG, OMG, OMG--what a monster HE was. Like clockwork--a broken alarm clock that won't shut off.

 I've decided there is simply no point for me--personally in my humble opinion only, and only in my opinion--to search for an upgrade in sound from another amp to best a certified Extreme--based on my own experience and those of many on this site, a certified Extreme might be as good as a dynamic headphone amp. can get. 

 Yes, I am a Proud Extreme Owner, like many others here, I stand before ye all with stones and admit it once more. I like to live dangerously, clearly.

 If I change my mind and do seek 'perfection' elsewhere, it would be like Billy Joel thinking he could do better than Christy. 

 STILL EXTREMELY HOT


----------



## PhilS

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_
 I've decided there is simply no point for me--personally in my humble opinion only, and only in my opinion--to search for an upgrade in sound from another amp to best a certified Extreme--based on my own experience and those of many on this site, a certified Extreme might be as good as a dynamic headphone amp. can get. 
_

 

I understand how you feel. Since I got my Supra back, I've listened to it every night. I can't identify any area where I would say it is lacking and would think that an upgrade or change to another amp would be something to consider. Maybe I'll consider trying some other phones just for fun, and maybe eventually I'll consider going balanced, but it just sounds so good with the tubes I've found that it is indeed hard to imagine it could get better.


----------



## Happy Camper

I'd love to hear markmaxx's balanced job.


----------



## The Monkey

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_Also consistent with experience--every time anyone says anything positive about an Extreme here, someone pops in and reminds us there were build issues; funny, as if this was not already well established, especially in this thread. Never mind the positive comments are on certified units. It's like there is a posse watching. Yea, Supreme beings are watching ready to smite any happy camper, or remind the forgetful, least we somehow can forget. Once in a blue moon, a picture of a relatively minor issue appears, followed by maybe a half dozen of the faithful chiming OMG, OMG, OMG--what a monster HE was. Like clockwork--a broken alarm clock that won't shut off.
_

 

Yeah, weird that would happen, especially in this specific thread.


----------



## nurxhunter

....not. Thanks for having sense of humor.


----------



## The Monkey

Indeed.


----------



## minimus

I suggest we start a new thread titled "Singlepower owners unite!" I suspect it would be shut down by the moderators pretty quickly. It would be like starting a thread "Camel smokers unite!" on a health forum.


----------



## PhilS

Quote:


  Originally Posted by *minimus* /img/forum/go_quote.gif 
_I suggest we start a new thread titled "Singlepower owners unite!" I suspect it would be shut down by the moderators pretty quickly. It would be like starting a thread "Camel smokers unite!" on a health forum._


----------



## kevin gilmore

for those of you that still think that mikhail was merely a bad businessman and the
 stuff was actually built ok, here are the latest pictures. The one big cap there
 has 20 amps of peak current running thru those globs of cold solder. And resistors
 attached to the top of the board only, and circuit lands torn off... No way stuff
 like this can have a long lifetime. As evidenced by significant early failure modes and
 filament voltages of 4.98 volts measured at the tubes.

 Yes its a plitron transformer. But not the RIGHT plitron transformer.
 You probably don't even want to know how much the person that bought this paid for it.

 Pictures with a macro lens and CLS flash.


http://gilmore.chem.northwestern.edu/ggsp1.jpg
http://gilmore.chem.northwestern.edu/ggsp2.jpg
http://gilmore.chem.northwestern.edu/ggsp3.jpg
http://gilmore.chem.northwestern.edu/ggsp4.jpg
http://gilmore.chem.northwestern.edu/ggsp5.jpg
http://gilmore.chem.northwestern.edu/ggsp6.jpg
http://gilmore.chem.northwestern.edu/ggsp7.jpg
http://gilmore.chem.northwestern.edu/ggsp8.jpg
http://gilmore.chem.northwestern.edu/ggsp9.jpg
http://gilmore.chem.northwestern.edu/ggsp10.jpg
http://gilmore.chem.northwestern.edu/ggsp11.jpg


----------



## spritzer

It does take real skill to mess up this badly. I really like picture nr.7 where one end of the resistor isn't even soldered...


----------



## atbglenn

Pretty amazing. Who taught Mikhail how do solder? Most of his solder joints didn't flow and will definitely fail in time.


----------



## nurxhunter

No one has posted more useful info. here than KG. In fact, most negative posts are simply BS; however, Dr. G's posts always provide useful information. Headfiers are lucky they can turn to him for guidance and even for repair. Kudos.

 However;......

 The bottom line remains:

 1) It is not known how many SP amps are out there--it is safe to say hundreds worldwide over 7 years (a guess would be 500-1,000). Only a very small percentage (a handful) of the amps have been shown to have inferior build quality. Most of these so far were non-stock amps. 

 2) A variety of DIY-ers have worked on the SP amps since the release of the MPX3 'Toaster' and PPX3 , and until very recently, *NO SIGNIFICANT ISSUES emerged from any of the experienced DIY-ers regarding build quality--for over seven years.* There would have been ample opportunity to joke about the 'Toaster'; yet, EVERYONE admired Single Power amps for years and years, until recently. The five SP amps I have owned were all of outstanding build quality, components and excellent soldering.

 3) Transformers on all Extremes should be upgraded. Once accomplished and with other components inspected, as would be done for any repair of any amp at any shop, the Extreme should be a keeper for a long time as a *REFERENCE GRADE HEADPHONE AMPLIFIER.* Even those who have seen the worst in a handful of amps remain 'proud extreme owners'. There is a reason for this.

 4) It is simply not possible to buy a better amp. for the price of upgrading ($175-$300 according to those who have done so, I paid $175 complete). The transformer upgrade is an expense, but not out of line with repair costs for tube amps in general. I have paid more for a pair of tubes.

 5) The posts on this thread--and on the bogus exploding cap thread--have reduced resale value by 30% or so. The ongoing negative posts ensure depressed resale value, which does no one any good, except for repair revenues.

 6) As last pointed out, this thread is meant for negativity, so it's fine to have a negative bias here--or at the 'explode like a grenade thread'.

 Moreover, Halloween is around the corner. Boo!

 7) Soon, there will be a SinglePower Appreciation Thread, because the style here (one negative post--several nay sayers chiming in in support, positive comments ignored or countered) seems quite boring.

 8) I do not care 'who taught Mikhail how to solder', which is getting very old, but I would love to know where he learned how to design. Clearly, he was a leader in this field for many years--unless--everyone will admit they are easy to fool in audiphilia, and most of this hobby is phychology, not physics.

 9) Had MR charged retail what others do for amps, of lesser build quality, and not accommodated custom work so readily, he might still be in business. The retail price of the PPX3 and MPX3 originally were $499, as I recall, compared to a Raptor for $1200. On used markets, the stock PPX3, MPX3 got (in the past) $450-$550. I know of no amp sounding that good for $500 used, but even they were bested by the Extreme at $650 used--or $900 or so when it first came out.

 10) Since Singlepower is dead, bashing the name is OK (no one will get sued), and bashing feels good to a handful, apparently. However, it does not explain how for so many years, EVERYONE loved EVERYTHING about SinglePower, including the soldering, component choices, build quality and most of all--sound.




][/url]







][/url]


----------



## immtbiker

Wow...
	

	
	
		
		

		
		
	


	




 He might have made some good amps in his early days, but the fact remains, that he took thousands of dollars which were never returned to his consumers (in money or product)
 and towards the end , the amps that he built were downright death defying.

*End of story.* 
 No excuses can be made for that type of activity, no matter how good your amp sounds.


----------



## mrarroyo

Dr. Gilmore, the pics you posted do not cease to amaze me. I am not good at soldering but if I did it for a living I would have gotten better w/ practice.

 I certainly appreciate the help you have given me and others and sure look forward to you graciously agreeing to check my amp. Besides fixing what you find incorrectly I have been thinking or putting better tube sockets and a larger transformer to accommodate dual 6BL7 for outputs.

 Thanks.


----------



## Happy Camper

Was the last set of pics from a Platinum Extreme KG?


----------



## atbglenn

Quote:


  Originally Posted by *mrarroyo* /img/forum/go_quote.gif 
_Dr. Gilmore, the pics you posted do not cease to amaze me. I am not good at soldering but if I did it for a living I would have gotten better w/ practice.


 Thanks._

 

Soldering was part of my job for over 30 years. From what I've seen posted here, the soldering is amateurish at best.


----------



## kevin gilmore

The last batch of pictures is guzziguys platinum extreme.

 I'm going to disagree with a number of items above.

 1) From what i understand there are about 500 to 600 total extremes out there.
 Some were built as extremes, others were mpx3 or ppx3 circuit boards converted
 to extremes (new) or the same things taken apart and turned into extremes.
 (used). So far absolutely every one of these has either a transformer problem, or
 a resistor problem. EVERY ONE. Plus all the rest of the problems. Of the bunch
 of units i have worked on so far, all but one had filament voltages <5.25 volts.
 (nope, not a mistype. FIVE point TWENTY FIVE)
 Definitely not a good thing for the expensive power tubes.

 1a) Every single ES1/ES2/Concerto... has a giantic design flaw that causes the
 output tubes to die an early death, sometimes with 4th of July style effects.
 3d21's are the only tubes spec'd for that kind of design voltage, and most people
 don't like the sound of the 3d21's. Every one of the very well built versions of
 these had the same design flaw. Wonderful chassis, and very decent assembly 
 job, but still massive design flaw. And this design flaw is not easy to fix without
 a forklift power supply upgrade, plus lots of chassis work for new pots and connectors.
 Besides the fact that 6sn7's just don't have enough voltage gain in that circuit
 to work right, and you get channel to channel imbalanced.

 The massive tweakability and all the tube adapters made everything MUCH
 worse. At least you can't tweek the output tubes on the extreme which is
 a good thing.

 5) The resale has certainly fallen. About as much as the parts plus labor it takes
 to fix them. The market in general is so soft that everyone is taking a hit.

 8) Mikhail learned how to design from the same places that just about every other
 manufacturer here did. Headwize and Tubecad. But few of those manufacturers
 are willing to acknowledge where they learned their trade.

 There is absolutely nothing new about any of mikhail's designs. His high voltage
 designs are a mix of old tube designs applied to solid state and really make no
 sense in the fact that many of the extra parts do nothing. The low voltage DC
 filament supply is the biggest disaster and is across all of mikhail's tube stuff.

 As has been pointed out elsewhere, tubes with AC filament supplies hum a little.
 Fact of life. But the output tubes used in the extreme were designed as power
 supply regulator tubes, and have huge current requirements. 6.3 VDC linear
 regulated 10 amp supplies really necessary for this kind of thing are as big
 as the amplifier itself. Just that one supply. Unfortunately 6.3 VDC switchers are
 not stock items and no one wanted to commit to a batch of those things.
 Besides which i personally hate switchers in any audio application. Other manufacturers
 have used 12 volt switchers bumped to 12.6 volts, and these are standard and
 very cheap items. So you might hear high frequency hash instead of hum.
 (unless you go for those 1mhz pure sine wave things which are nasty expensive)

 So mikhail clearly gets the award for managing to cram an extreme into a box that
 size. And with a bit of work the things can be made reliable for a very long time.

 So i would flip it around. Say 10% of the stuff out there actually works right, and
 the rest of the stuff needs work.

 And a lot of it is mikhail's fault for continuing to try and build purely custom stuff
 where every single unit is different. If i was in this business, and i'm not, and never
 will be, and wanted to do this kind of custom work, the resulting prices would be
 so out of line that a different business model would be required. I'm not sure that
 there are enough people out there to keep a person in business making headphone 
 amplifiers in the $30k to $50k range although the one company at RMAF showed 
 some of the most gorgeous speaker amplifiers in that price range and they have 
 been in business quite a long time.

 mikhail giving out long warranty times, and the stuff failing at a rate that would
 sink any manufacturer of any size made it worse. Can't build and sell new stuff
 at a profit and stay in business when you are spending every possible hour fixing
 (and loosing money) on repairs.

 Even Krell recently took on a management partner. (and a bundle of investor bucks)


----------



## nurxhunter

All good points. What about:

 "2) A variety of DIY-ers have worked on the SP amps since the release of the MPX3 'Toaster' and PPX3 , and until very recently, NO SIGNIFICANT ISSUES emerged from any of the experienced DIY-ers regarding build quality--for over seven years. There would have been ample opportunity to joke about the 'Toaster'; yet, EVERYONE admired Single Power amps for years and years, until recently. The five SP amps I have owned were all of outstanding build quality, components and excellent soldering."


 Agreed, every Extreme needs a new transformer. Apparently, it sounded good enough even with an under-rated transformer. This is now fact, and thanks to info here, the upgrade was painless and not too expensive.

 So the puzzle is--how was it that SP was so lauded for so long by so many? Frankly, I am puzzled.


----------



## markmaxx

Quote:


  Originally Posted by *Happy Camper* /img/forum/go_quote.gif 
_I'd love to hear markmaxx's balanced job._

 

That may be possable 
	

	
	
		
		

		
			





 If you are ever in the DC. area you are more than welcome to stop by!!!! I may go to the NY. Meet. and it looks like we might have a DC. meet soon. 

 I too need to find someone to "go through" mine, as I would like to grow old with it. (where do I start as far as finding someone to work on mine?) . 

 I tried to sell mine also, it is still mine.
	

	
	
		
		

		
		
	


	




 Nice looking on the outside!


----------



## kevin gilmore

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_All good points. What about:

 "2) A variety of DIY-ers have worked on the SP amps since the release of the ......._

 

There were plenty of pictures of the insides of the toasters. Much
 discussion on the wiring job may have been suppressed or deleted.
 But some discussion did survive. The biggest issue that people are
 finally finding out is that it does not have to be built like that to
 sound good.

 Some people needed to keep up the illusion so that they could dump
 their units without taking too much of a bath.

 But the biggest problem was rampant fanboyism.

 The people that now own SP amps are the ones that really like them
 and will do whatever is necessary to get them fixed. This is a good
 thing. In the long run these amps in the future will start increasing
 in price.

 Maybe someone will even build and sell extremes built correctly.
 There may be a market for amps like this in the $2k to $3k range.
 Definitely not a market for ppx/mpx like things in my opinion.


----------



## immtbiker

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_So the puzzle is--how was it that SP was so lauded for so long by so many? Frankly, I am puzzled._

 

The answer is simple. Most people didn't or better yet, *couldn't* open their amps and see the craftsmanship.

 I asked Mikhail 5 times to show me pictures of what my Maestro looked like inside, and he put me off, giving me varying excuses.


----------



## nurxhunter

I know for sure that in 5/5 of the SP amps I owned, all were very well constructed with high quality parts. What great luck.

 Yes, no one could open their cases for seven years. That must be it.

 Yes, the wiring on the toaster I owned--as well as an MPX3 in the final casework-- was not as ordered as I am accustomed to--but--that is of NO SIGNIFICANCE--none whatsoever with respect to tone or safety. Must be other wiring issues that were deleted--though I never heard of them. 

 The situation is not so simple--not by any means at all. But, at a certain point, one begins to 'get it' and moves on. This thread is not the place for positive points on SP. Sorry. Wrong number.

 Thanks, though, for taking trouble to respond. Much appreciated, as always.


----------



## kevin gilmore

Maybe after i'm done with the T2 and SRX2 i'll do a diy balanced extreme board.
 Trouble is with the teflon sockets and either dact or rk50, its not going to be
 cheap to assemble. Plus chassis and real power supply, it could get to $4k in
 parts real easy.


----------



## n_maher

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Maybe after i'm done with the T2 and SRX2 i'll do a diy balanced extreme board.
 Trouble is with the teflon sockets and either dact or rk50, its not going to be
 cheap to assemble. Plus chassis and real power supply, it could get to $4k in
 parts real easy._

 

I'd like see the power supply for that beast.


----------



## Bolder

Here are some photos of a Platinum Extreme sent to me.

 This one was built on a MPX board.






 The light blue cap in the middle is the smoothing cap for the filament supply. Does it look like it may have been under some stress?

 BTW, filament voltage was measured at 4.0.






 Other side of the board.






 It may be hard to see at this resolution but the solder joint has gotten so hot that the solder has flowed out of the connection.

 This unit has a Plitron transformer, but as Dr. Gilmore mentioned earlier, it is the wrong one for use in an Extreme. I have discussed this unit with it's owner. It will be gutted and the Extreme circuit built point to point. The transformer will be replaced with an Electraprint custom built one.

 Here is my favorite shot from the Singlepower units sent to me for evaluation.






 This is the tubed, external power supply for a Concerto ES-1 (combination of a Maestro dynamic amp and ES-1 electrostatic amp).


----------



## immtbiker

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_Yes, no one could open their cases for seven years. That must be it._

 

Nasty, un-called for remark. There are 2 ways of saying anything.

 Obviously, anyone who has owned 5 amps from the same company is going to defend it to it's death if they didn't have any problems. But the fact remains that Singlepower made it nearly impossible for the non-technical to open their amps.

 Now why would that be, I wonder?


----------



## kevin gilmore

And i thought the cap soldered to paper clips was bad.
 That thing is pretty much unrepairable.
 If its the tubed power supply, it was something over $7.5K originally...

 Maybe it is time to start on that diy balanced extreme board...


----------



## markmaxx

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_I agree. In the end I do somewhat marvel at what the "real" transformer looks like when it's large enough to supply the power required.

 I read, and I think once even saw, a balanced Extreme. I wish I knew who the owner was, that amp has to be in seriously bad shape. 
	

	
	
		
		

		
		
	


	


_

 

I have it!!!!
	

	
	
		
		

		
		
	


	




 I wish I had a better picture. Aaron, it "was" a bitch to open. [size=large]Kevin can I send this one to you???[/size]


----------



## The Monkey

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_And i thought the cap soldered to paper clips was bad.
 That thing is pretty much unrepairable.
 If its the tubed power supply, it was something over $7.5K originally...

 Maybe it is time to start on that diy balanced extreme board..._

 

But they sound so good!


----------



## smeggy

pics or ban!!!


----------



## El_Doug

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Maybe it is time to start on that diy balanced extreme board..._

 

please, not before the T2 
	

	
	
		
		

		
		
	


	




 words cannot describe how interested i am in the whole kit and kaboodle for that one


 edit: i see you mentioned you are still working on it earlier. hooray!


----------



## diego

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_Maybe after i'm done with the T2 and SRX2 i'll do a diy balanced extreme board.
 Trouble is with the teflon sockets and either dact or rk50, its not going to be
 cheap to assemble. Plus chassis and real power supply, it could get to $4k in
 parts real easy._

 

How about an unbalanced board? I would buy one for sure.


----------



## mrarroyo

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_ ... Definitely not a market for ppx/mpx like things in my opinion._

 

Hi Dr. Gilmore, as the owner of an MPX3 would you please expand on this? Thanks.


----------



## kevin gilmore

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_I'd like see the power supply for that beast._

 

And here you go.
http://gilmore.chem.northwestern.edu/fpower1.jpg
http://gilmore.chem.northwestern.edu/fpower2.jpg

 6.3 volts at 35 amperes. You actually need something this
 big because of the low starting resistance of the output tubes.
 So if it is a linear supply done right, it really is this big.
 Otherwise you need a switcher.

 My comment on the MPX3 things is that i don't think there is enough
 people out there willing to pay for a correctly designed and built MPX3.

 There are evidently a lot of people who want extremes, and balanced
 extremes to warrant someone doing a correct build job on those.
 Or a diy kit anyone could assemble.

 OK, a couple of quick pics.
http://gilmore.chem.northwestern.edu/t2chassis1.jpg
http://gilmore.chem.northwestern.edu/t2chassis2.jpg
 more later when i finish the tops and bottoms.


----------



## Born2bwire

Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_No one has posted more useful info. here than KG. In fact, most negative posts are simply BS; however, Dr. G's posts always provide useful information. Headfiers are lucky they can turn to him for guidance and even for repair. Kudos.

 However;......

 The bottom line remains:

 10) Since Singlepower is dead, bashing the name is OK (no one will get sued), and bashing feels good to a handful, apparently. However, it does not explain how for so many years, EVERYONE loved EVERYTHING about SinglePower, including the soldering, component choices, build quality and most of all--sound._

 

Fact is, people are easy to fool, especially when they want to be. Mikhail has been called out many years ago about the reliability of his amps and the quality of his work. Most of the time, it got lost in the noise of the rabid fans that would not believe it or found ways to rationalize it. I remember many years ago going to a Head-fi meet in Chicago and asking about why there weren't any Singlepower amps. I was told that Mikhail sent two but they arrived DOA. I recall the long threads about the quality of work being done in the point-to-point wiring and how the tie downs and work was shoddy and maybe dangerous/unreliable (in response Mikhail finally went to PCB).

 This has been a situation that has been developing for many many years now. But I think many people ignored it or rationalized it because Mikhail seemed to be popular, was active in Head-fi, and produced products that a lot of people felt sounded great. The fanboyism was really extreme, I can't tell you how ridiculous it got. Another factor is, how many times do people actually open up their amps, and of those that do, how many are qualified to make a judgement call on their build quality?

 EDIT: Just remembered some of the RSA vs. Singlepower crap that's been pulled over the years. Dear God, how do people actually get like this? Sigh... To me, that was one of the biggest reasons why this never got the attention it deserved earlier. Fanboys of Singlepower wouldn't tolerate any kind of criticism, and anybody who laid down criticism were labeled as rabid anti-Singlepower fanboys of camp RSA or whatever regardless.


----------



## n_maher

Quote:


  Originally Posted by *diego* /img/forum/go_quote.gif 
_How about an unbalanced board? I would buy one for sure._

 

It's pretty simple to do point to point and heck, if I can do it anyone can. I've already posted internal wiring shots of the amp that should make it even easier.


----------



## The Monkey

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_It's pretty simple to do point to point and heck, if I can do it anyone can._

 

Yeah, you've got such sloppy skillz.


----------



## thisbenjamin

Quote:


  Originally Posted by *The Monkey* /img/forum/go_quote.gif 
_But they sound so good!_

 

I'm thinking, someone should start a thread /research how different paper clips "sound".


----------



## smeggy

Damn, I thought my new supplies were beasties at 6.3V 10A


----------



## HeadphoneAddict

Quote:


  Originally Posted by *thisbenjamin* /img/forum/go_quote.gif 
_I'm thinking, someone should start a thread /research how different paper clips "sound"._

 

Certainly the length of burn-in will vary among the different clips.





 j/k


----------



## thisbenjamin

everyone knows paperclip burn-in is a myth. pffft.


----------



## Bolder

Sorry to be the bearer of bad news, but the Plitron transformers used in the Singlepower Extreme Platinum are wired up the same way as the Hammond transformers discussed in the first post in this thread.

 The dual primary taps, which are supposed to be run in parallel for 120 V and series for 240 V are split off and one is used for the HV section of the tube circuit.

 The only thing used on the secondary is the 6.3 V tap. As part of the primary is being used to power the HV section, there is not enough current to supply the filaments, as evidenced by my reading 4 volts at the tube sockets.

 The Plitron transformer should be replaced for safety and to get the sound out of the amp that you paid for. In the case of the amp I have here, it will be replaced with an Electra-Print transformer. 

 When I spoke to Jack at Electra-Print today, he mentioned that he is expecting a good sized order for some other transformers to be placed very soon. He will be busy for 4 weeks building those, so he cannot build anything else for up to 5 weeks.


----------



## kevin gilmore

Plitron transformer not unsafe like the hammond, but still this is a misuse of
 the transformer. At least the transformer is overspec'd enough so that it
 works without overheating. Problem is many of these will have visible holes
 in the chassis if you swap out to the electraprint transformer...


----------



## PhilS

Quote:


  Originally Posted by *Born2bwire* /img/forum/go_quote.gif 
_Mikhail has been called out many years ago about the reliability of his amps and the quality of his work. Most of the time, it got lost in the noise of the rabid fans that would not believe it or found ways to rationalize it.

 * * *
 Fanboys of Singlepower wouldn't tolerate any kind of criticism, and anybody who laid down criticism were labeled as rabid anti-Singlepower fanboys of camp RSA or whatever regardless._

 

Blaming the problems on "fanboys" is just silly, IMO. And I've always marveled at the term "fanboy." Does that mean someone likes something. I like to eat at Chick-Fil-A. Am I a Chick-Fil-A "fanboy"? If I tell a friend Chick-Fil-A makes the best fast food, and he eats there and gets food poisoning, am I to blame?

 Mikhail did a lot of bad things. It's _his _fault. Blaming the problems, even in part, on people who really liked the sound of his amps (and still do) and exercised their rights on a public forum to say what they believed or experienced is just plain unwarranted, IMO (and that's putting it mildly).


----------



## The Monkey

Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_Blaming the problems, even in part, on people who really liked the sound of his amps (and still do) and exercised their rights on a public forum to say what they believed or experienced is just plain unwarranted, IMO (and that's putting it mildly)._

 

That argument kinda cuts both ways, no?


----------



## PhilS

Quote:


  Originally Posted by *The Monkey* /img/forum/go_quote.gif 
_That argument kinda cuts both ways, no?_

 

Sorry, you lost me completely.


----------



## The Monkey

That's ok.


----------



## immtbiker

Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_I like to eat at Chick-Fil-A. Am I a Chick-Fil-A "fanboy"? If I tell a friend Chick-Fil-A makes the best fast food, and he eats there and gets food poisoning, am I to blame?_

 

No, but if you told everyone that you knew, that loved and purchased chicken, that Chick-Fil-A was the best chicken your ever tasted, you *would* be a Chick-Fil-A fanboy. 

 That wouldn't necessarily be a bad thing.


----------



## Born2bwire

Quote:


  Originally Posted by *PhilS* /img/forum/go_quote.gif 
_Blaming the problems on "fanboys" is just silly, IMO. And I've always marveled at the term "fanboy." Does that mean someone likes something. I like to eat at Chick-Fil-A. Am I a Chick-Fil-A "fanboy"? If I tell a friend Chick-Fil-A makes the best fast food, and he eats there and gets food poisoning, am I to blame?

 Mikhail did a lot of bad things. It's his fault. Blaming the problems, even in part, on people who really liked the sound of his amps (and still do) and exercised their rights on a public forum to say what they believed or experienced is just plain unwarranted, IMO (and that's putting it mildly)._

 

Do we really need to bring all of this up? If your friend had food poisoning that was linked back to the restaurant would you still go around and tell people that it's worth eating there? Would you tell your friend that he's confused, that after the tenth food poisoning case it's still a coincidence? If your friend opens up his sandwich and asks you about the green thing grazing on the lettuce would you tell him nevermind, it still tastes fantastic?

 This started over five years ago. You can still find the threads about it if you want and heck, the pictures are still up: http://www.head-fi.org/forums/f5/ins...ml#post1013679

 I look at that and cringe. Most of the components are not secured, the wiring and layout is completely haphazard, the soldering is amateur. You can still see rosin everywhere and there's even an electrical twist-cap in there. Then, in the face of this, people carry attitudes like this: http://www.head-fi.org/forums/f5/ins...ml#post1013806

 "He has enough crediability, clientelle and respect in the industry to probablly need not a dime of anyone here that doesn't seem to respect his work. Perhaps you are all right? I don't know, but atleast give the benefit of the doubt... "

 That's almost word for word what I was talking about. There is more than just sound quality. Reliability and customer service are important aspects to anyone that has ever been caught on the badside of a warranty. Glossing over these problems, rationalizing them, or just dismissing them as uncredible rants of competing fanboys does a disservice to the community. It only helps the continuation of poor business practices and quality control.

 nurxhunter asked why people still loved his products (sound quality and build quality) after all these years and the reason for that lies completely with the people. The extent that people carried this went far over any rational extreme. I'm not interested in bringing all this up again in specifics, I only wanted to provide nurxhunter with some context that allowed for this to happen for so long. And to me, that was because that the ridiculous behavior of people prevented valid concerns and questions being raised, discussed, and considered. Mikhail produced shoddy products, performed unsatisfactory customer service, and stole people's money. That was him, but the reason why his products remained popular for many years is something different that I cannot totally place on Mikhail. Just because somebody sells a lot of products, participates in the community, and produces amps that sound good does not mean that they should be exempt from the same scrutiny that other sellers are under. There have been many established members and merchants on Head-fi that have burned the community over the years.

 This is all I'm going to say on this because this is not the thread to be discussing this any further.


----------



## n_maher

I'm going to let the comments made so far stand and not do any pruning but I would respectfully ask that we keep this thread semi-on topic so that it can still have some useful value to the (potential) hundreds of other SP owners out there.


 [edit]I lied, personal attacks won't be allowed to stand.


----------



## John D.

Good News Post

 Well I finally quit procrastinating and drove up to Brooks Berdan in Monrovia, for a check-up on my standard Extreme. After opening up the amp, the only thing that needed attention was a resistor too close to the board, raised it up a little and re-soldered it. Transformer appeared to be fine. Maybe some of these early units received a little more attention.

 That's it guys, I feel much better now, I really do like this amp.


----------



## The Monkey

Good news, John D. Would you mind letting us know the date of your unit (or reminding me if you've posted already)?


----------



## Happy Camper

It can't be your honor! They are all made by..........

 I'm glad to hear that not every one of these amps are (potential) IEDs, awaiting the signal from 

. Who knows, perhaps these bad amps were intentionally damaged to kick a non-paying vendor off here. OK, gag order back in place to save the innocent.


 Of course this sounds offensive. Of course it's crazy talk. Accusing someone of being guilty of complicity by making a positive comment on their amp is just as offensive and crazy. 

 John D, do you have a board ID? PPX3 Rev.A 2006/ Extreme Rev.C 2007 etc.? Also, did you get your transformer model? If it was wired the same way the others were found, it could still be a potential hazard but you haven't driven it hard enough to show signs yet.


----------



## John D.

Quote:


  Originally Posted by *The Monkey* /img/forum/go_quote.gif 
_Good news, John D. Would you mind letting us know the date of your unit (or reminding me if you've posted already)?_

 

Sorry, 

 I didn't have a camera with me at the time, and did not write down any board info. But, I bought this amp in Sept. of 07 from a member on this forum, at the time he stated he was the 2nd owner, and the amp was a couple of months old. I use this amp just about every day, at least 2-3 hours at night, and more on the weekends. That makes me the 3rd owner, and I'm keeping it.


----------



## kevin gilmore

So as many people know, the tube sockets mikhail consistently used were
 pretty much junk. But they are a non standard size, and using decent sockets
 ended up being grief. Well i have found a way...
 Take .025 off of them and they fit absolutely perfect.

http://gilmore.chem.northwestern.edu/masp5.jpg


 and the results...
http://gilmore.chem.northwestern.edu/masp6.jpg
http://gilmore.chem.northwestern.edu/masp9.jpg

 trouble is, its about 6 hours of labor to dig the old tubes sockets out of there...
 Worse if you have the version with the circular clip that is epoxied in...
 Then you have to remove the board all the way and drill extra holes.


----------



## immtbiker

Quote:


  Originally Posted by *kevin gilmore* /img/forum/go_quote.gif 
_trouble is, its about 6 hours of labor to dig the old tubes sockets out of there...
 Worse if you have the version with the circular clip that is epoxied in...
 Then you have to remove the board all the way and drill extra holes._

 


 Miles to go, before I sleep....


----------



## mrarroyo

Nice work there Dr. Gilmore!


----------



## mikeymad

x2


----------



## spritzer

Mmmm teflon sockets.


----------



## junerpp

Here are the pics of the internal of my MPX3 Slam SE with supra transfomer. My amp has an rob in the rear to choose the high/low voltage.
 Please help me to check it. Thanks for any info.


----------



## Happy Camper

Jun,

 You have the same issues as mrarroyo's amp. You can see heat damage under your board.


----------



## n_maher

Quote:


  Originally Posted by *Happy Camper* /img/forum/go_quote.gif 
_Jun,

 You have the same issues as mrarroyo's amp. You can see heat damage under your board._

 

He's got more than that, the hi/lo switch is amazingly dangerous. It's rated for ~30V and is switching several hundred volts. 
	

	
	
		
		

		
		
	


	




 I wouldn't turn that amp back on until I had a professional look at it.


----------



## junerpp

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_He's got more than that, the hi/lo switch is amazingly dangerous. It's rated for ~30V and is switching several hundred volts. 
	

	
	
		
		

		
		
	


	




 I wouldn't turn that amp back on until I had a professional look at it._

 

Does it seems that the transformer output much high voltage into the board than usual MPX3 and Marrayo's ? Why it use 6 parelled resistor ( rated as 2.5Kohms, 5%, 5W) and two stacked capacitor in the middle? And it seems that the 6 parelled resistors have been burnt up.


----------



## n_maher

I have no clue what Mikhail was trying to do with this amp, but it's clear that he failed miserably. The parallel/series resistor group was certainly an effort to better dissipate heat, which failed, and the stacked caps was likely a result of needing a high voltage rating but I can't be sure there. 

 Honestly I don't know where to tell you to start when it comes to fixing this particular amp. It's in bad shape, that's for sure and you're probably lucky that something very bad has not happened as a result.


----------



## junerpp

Quote:


  Originally Posted by *n_maher* /img/forum/go_quote.gif 
_I have no clue what Mikhail was trying to do with this amp, but it's clear that he failed miserably. The parallel/series resistor group was certainly an effort to better dissipate heat, which failed, and the stacked caps was likely a result of needing a high voltage rating but I can't be sure there. 

 Honestly I don't know where to tell you to start when it comes to fixing this particular amp. It's in bad shape, that's for sure and you're probably lucky that something very bad has not happened as a result._

 

Thanks for the info. And I should find an experienced tech to help me fix it. If any idea come through about how to fix it, please let me know. And I appreciate any inputs.


----------



## Bolder

Your amp is in fairly poor shape with all the overheated parts.

 The high voltage circuit should be removed. It does not improve the sound when running the output tubes at high voltage. If anything, it degrades the performance. The switch is rated 25 volts. It is likely to fail at any time. The switch should be used to change sources, not in high voltage circuits.

 If you are familiar with procedures of working on high voltage tube amps, the next step would be to measure the filament voltage. With all tubes in, a load (headphones) plugged in and power turned on. VERY carefully measure across pins 7 and 8 of the output tubes. 

*DO NOT DO THIS if this is the first piece of tube gear you have looked at. You CAN hurt yourself and the amp very badly if a probe slips and touches the wrong point!*

 If the voltage measured is below 6 volts, I would suspect that the transformer does not supply enough current for the tubes being used.

 If the filament voltage is low, you are looking at a transformer replacement, replacement of the overheated diodes in both HV and filament circuits. Removal of the higher voltage circuit, replacement of the voltage dropping resistors, installation of bleeder resistors across the power supply caps and probably one or two other surprises. 

 The circuit board can be rather difficult to remove and re-install. Most of the screws used are secured with Loctite and have to be heated to very high temps to loosen the grip of the chemical adhesive.


----------



## Happy Camper

If available, I'll bring a meter for the Columbus meet and have a looksee. 

 Jun, good luck finding a tube amp tech. Let me know if you find one and I will do the same. I've found a retired Navy guy in Dayton who's a radio professional/ham hobbyist. If he pans out, I'll let you know.


----------



## junerpp

Quote:


  Originally Posted by *Happy Camper* /img/forum/go_quote.gif 
_If available, I'll bring a meter for the Columbus meet and have a looksee. 

 Jun, good luck finding a tube amp tech. Let me know if you find one and I will do the same. I've found a retired Navy guy in Dayton who's a radio professional/ham hobbyist. If he pans out, I'll let you know._

 

Thanks, and hope someone in the meet can help me check and figure out how to fix my amp. 
 BTW, I think it's running out of time to conform the meet place and determine the gear list. Do you find someone also in the OSU willing to take the job with me or not? I am a newer here, so I don't think I can take everything by myself.


----------



## Bolder

Here are some shots of the latest Extreme to visit me. 

 First is the standard overheated transformer.







 In this amp's case, it led to failure of the capacitor in the filament circuit.






 In other words, the cap puked it guts out.

 Here is the bottom of the case with more cap puke.






 As an added bonus, it certainly looks like the large film cap in the HV power supply was never soldered in place.


----------



## kevin gilmore

here is the latest surprise.
http://gilmore.chem.northwestern.edu/mmax1.jpg

 all the cable ties are broken. Which happens a lot. But mikhail superglued
 the cable ties to the capacitors. So when i removed the superglued parts
 some of the plastic protector on the capacitors came off.

 Warning to all that have the black gate output caps. when the plastic
 breaks off, and exposes the can, the can is electrically hot, and tied to
 the minus terminal of the cap.

http://gilmore.chem.northwestern.edu/mmax3.jpg

 And if you have stacked caps, and they are wired to different output
 channels you have to insulate them from each other.

 I'm not going to discuss the 3 major ground loops inside this thing.


----------



## Bolder

Here is a nice, fuzzy shot of a completely rebuilt Extreme.






 This unit was pretty much stripped to the chassis. The RCA input connectors, AC inlet, AC switch, volume control, LED and headphone connector are just about the only things left from the stock unit.

 The transformer was replaced with a Electra-Print. The filament circuit is an all new design. Everything is point to point wired. The circuit boards were built from scratch using turrets for wire connections. The tube sockets were replaced. The input wiring are shielded, twisted pairs.

 There were some Black Gate caps used in the power supply. They were re-used as output coupling caps. I kept one of the Black Gates in the HV supply. New caps are Panasonic. All electrolytic caps are bypassed with film caps mounted on the underside of the boards.

 The amps has just been running for about 24 hours and is breaking in nicely. Great dynamics and very good extension into my HD-600s. The back of the case where the filament bridge is now mounted and the transformer are warm to the touch, but in no way hot.


----------



## .Sup

GJ Bolder


----------



## vcoheda

so the only thing salvageable was the chassis. good grief.


----------



## spritzer

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.


----------



## peanuthead

So if you rebuild a Singlepower with new components and change certain aspects of the design, is it still a Singlepower?


----------



## spritzer

No and that is a good thing. My ES-1 is much truer to the original design then that hack job Mikhail shipped out.


----------



## nurxhunter

It sure would be nice if true measurements could be taken on what a SinglePower Extreme scopes out 'before' and 'after'. What a concept, let data do the talking.


----------



## Skylab

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'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.


----------



## 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.










[/url][/IMG]

 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.


----------



## spritzer

We know that the mini tube amps have the same transformer setup (and run very hot), some of the larger tube amps (SDS-XLR for instance) have filament transformers which are way too small and the same goes for most if not all the "high current" upgrades. Some of the basic stock amps might have these 266 Hammond transformers but there is no way to really check. 

 Another potential issue was the common SP policy of reusing parts from other amps. Hard to know for sure if something was reused as the way the P-P amps were built it would be easy enough to just removed a whole section and put it in another amp.


----------



## Skylab

My only point from a while ago is that I felt it was going to DISCOURAGE SP amp owners from actually having their amps evaluated and repaired by proclaiming that every SP amp ever made will require complete gutting except the chassis. This was not true in the case of my amp, and I expect not true in the case of others. Mine DID require serious repair - a new trafo and some new resisters. But that was still more economical than buying a new amp of similar quality.

 Saying they all have to be completely junked and can't be just repaired is likely to cause some people to just keep using amps that really need to be examined and repaired.

 Bottom line is that EVERY SP amp should be checked out _thoroughly_ by a truly qualified person/company before being used again. I am very grateful to Nate for originally pointing out that my Extreme had a dangerous flaw.


----------



## spritzer

Fair point and every amp should be looked at. Most often opening it up and posting pics is enough to identify the majority of the issues and some can be minor. I do prefer to start over as you will end up with a better amp in the end, better design with better execution. I'm certifiable though with 3K$ in DIY parts this month already so I may be living on the fringe...


----------



## tagosaku

I really appreciate this thread even though I don't understand most of it. Question from a lazy MPX owner. 
 I have a MPX with Piltron upgrade. (2004 built, last visit to Denver was 2008 but he didn't charge me for the fix so I am assuming he didn't lie to me.)
 1. The transformer becomes luke warm at most. Nothing close to 'hot'.
 2. I am usually in the room when the amp is on.

 Will this make a good enough excuse not to take the unit in?


----------



## Happy Camper

Internal pics posted will let some knowledgeable people check the known areas for visual evidence of problems. Transformers aren't the only problems with these units.


----------



## mrarroyo

Quote:


  Originally Posted by *spritzer* /img/forum/go_quote.gif 
_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._

 

If this response is w/ regards to my post above I continue to disagree with you. You would be hard pressed to find a better technical/knowledgeable person than the individual who looked at my amp. I even asked if there was anything else that had to be done or should be done and he said no. If your response has nothing to do with my post, please disregard what I just wrote here. 
	

	
	
		
		

		
		
	


	




  Quote:


  Originally Posted by *nurxhunter* /img/forum/go_quote.gif 
_ ... 

 MR: hard to defend someone who simply slipped off The Big Boat and ended in the Deep End and rear ended many as he was going down. Clearly, was not and is not trustworthy. EOS. ..._

 

If this is due to my post I fail to see the significance of your response.


----------



## Happy Camper

If you have a safe unit, yes, the amp works well with the 70x.


----------



## Frihed89

I have to agree with Miguel. We only see the worst examples, here. There are a lot of PPXs and MPX models that are doing just fine. The problems with Supras, MPX3 Slam SEs, and Extremes seen here are all fixable by an experienced tube tech. Some of the other SP "mistakes" (like the one with the fancy case with a bunch of wall warts in it) are in an entirely different category, perhaps totally or close to totally FUBAR.

 It's hard to generalize across all the amps they made.


----------



## CrackBerry9000

Is there a sticky with places that can be used for repair? Maybe if people see a listing that is not on the other side of the country then having an amp evaluated and or fixed wouldn't seem like such a big task. People could add to it and rate their experiences. Seems like it would be useful anyway


----------



## markmaxx

Quote:


  Originally Posted by *CrackBerry9000* /img/forum/go_quote.gif 
_Is there a sticky with places that can be used for repair? Maybe if people see a listing that is not on the other side of the country then having an amp evaluated and or fixed wouldn't seem like such a big task. People could add to it and rate their experiences. Seems like it would be useful anyway_

 

The person that went through my balanced Extreme, did it as a favore to me and wants to remain anonymous, because of the sheer volume of work. Not everyone with a Singlepower amp that's should be gone through has posted here. Their is a lot that goes on by PM.
 Also my Guy said Makhails electrostatics amps are a mess! Too


----------



## CrackBerry9000

Quote:


  Originally Posted by *markmaxx* /img/forum/go_quote.gif 
_The person that went through my balanced Extreme, did it as a favore to me and wants to remain anonymous, because of the sheer volume of work. Not everyone with a Singlepower amp that's should be gone through has posted here. Their is a lot that goes on by PM.
 Also my Guy said Makhails electrostatics amps are a mess! Too_

 

Then obviously you would not add him to the hypothetical list, right? I wasn't really talking about friends of friends but professionals that some of you may have used. This would be a good resource for the community right?


----------



## mrarroyo

A few have used Boulder to fix their Singlepower amp.


----------



## HeadphoneAddict

Quote:


  Originally Posted by *mrarroyo* /img/forum/go_quote.gif 
_A few have used Boulder to fix their Singlepower amp._

 

I think it's Bolder? (no "U")


----------



## mrarroyo

Ok, who put that U there? It wasn't me! 
	

	
	
		
		

		
		
	


	




 that is my story and I am sticking to it.


----------



## yuinlover

Maybe we need to pm a link to this thread to all users who list "Singlepower" in their profile. Or just send it to all, better be safe than sorry.


----------



## Skylab

We should also sticky this in the "Headphone Amps For Sale" forum. I am still shocked how I see people trying to sell Extremes in their stock form, for basically full price, and saying "I have never had any problem with mine, so it must be fine" - I had never had any "problem" with mine either - but the transformer was well on it's way to burning up, and at some point soon something VERY bad would have happened...


----------



## sainttoad

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_We should also sticky this in the "Headphone Amps For Sale" forum. I am still shocked how I see people trying to sell Extremes in their stock form, for basically full price, and saying "I have never had any problem with mine, so it must be fine" - I had never had any "problem" with mine either - but the transformer was well on it's way to burning up, and at some point soon something VERY bad would have happened..._

 

I think that in my own FS post I was pretty open and detailed about the state of my amp and its stock (and improperly wired) transformer. I also think I've priced it pretty fairly, even for the case where a buyer immediately replaces the transformer. IMHO, it sounds like a $1000 amp or better, so that's how I've priced it.

 I have read this entire thread, and as mentioned in my FS post, had my amp checked out by someone whom I feel is qualified. I concluded that even though "at some point" the transformer would melt, since I've barely used the amp, I'm nowhere near that point. By all reports here, the transformer will not fail suddenly and without warning, but after a period of obvious darkening. Since the transformer cover on my amp is unattached, any buyer is free to perform daily inspections and replace the transformer at the first sign of discoloration.

 The tubes are receiving the proper voltage according to their datasheets, the soldering is competent, no components are used out of spec, and the grounding is good. At this point, my Single Power Extreme is the most thoroughly inspected piece of electronics I own, and I feel safer listening to it than driving my Camry 
	

	
	
		
		

		
			





 I have no objection to making this thread sticky in FS, or even adding a link to it in my own FS post, but I think both measures are overkill: this thread is already in the top google hit for "Single Power Extreme", and I would assume anyone looking to buy a high end amp would at least google it, and then discover the entire sordid tale of Single Power.

 Those are my reasons for wording my FS post as I did, but I consider myself a part of this community and certainly do not want another member to injure themselves or feel ripped off buying my amp. I know how I felt when I stumbled across this thread and found out about Mikhail - I don't want people feeling that way about me! So, I welcome any comments on my FS post:

http://www.head-fi.org/forums/f42/fs...xtreme-476775/

 For what it's worth, the fact that nobody has bought it yet is a pretty strong comment in itself.


----------



## Skylab

Actually, I was not referring to your ad in any way. I think you've been pretty clear. But if you look, there are ads running right now that are FAR vaguer than yours, where there has been no inspection of the amp AT ALL.


----------



## sainttoad

Quote:


  Originally Posted by *Skylab* /img/forum/go_quote.gif 
_Actually, I was not referring to your ad in any way. I think you've been pretty clear. But if you look, there are ads running right now that are FAR vaguer than yours, where there has been no inspection of the amp AT ALL._

 

Yeah, at first I thought you meant me, then I looked at the ads and saw some that were worded just like your comment above. Still, like I said, I don't want anyone to get hurt or feel ripped off, so I figured I'd make sure I was being as open as I thought I was being.

 On a related note, Single Power's website is now completely gone. Not that it ever had any useful information...


----------



## FallenAngel

That's not nearly as scary as this AudioGon listing:

 This one's a gem! No marks, scratches or blemishes, and you know how good these are. It has all the upgrades, as I have done every meaningful mod to make it the very best sounding headphone amp it can be. Simply put, you won't find a better one and you'll be elated with the sound and performance for years to come. It also has over a year left on the warranty transferable to you along with a wide assortment of tubes to personally tailor the sound. I just don't use it enough to justify keeping it anymore.

 Here's what you get:

 2 sets of SE inputs on back
 High/Low voltage bias adjustment switch for 6bl7 and 6bx7 tubes
 Upgraded Jensen audio cap for voltage regulation
 Blackgate cathode caps
 Blackgate output caps
 Soniccraft platinum teflon coupling caps
 Upgraded stepped attenuator
 Upgraded power supply caps
 Upgraded "SLAM" adapters
 Auto bias
 Upgraded large "SUPRA" transformer
 ECC adapters for use with 7n7, 6414, 5687, 2c51/396a and other high gain tubes

 Plus a wide assortment of tubes:

 6 - 5687 tubes
 14 - 6bl7 tubes
 2 - 2c51 tungsol tubes
 1 - 2c51 sylvania tube
 2 - 12av7 tubes
 1 - 6sn7 tube
 2 - 7n7 tubes
 2 - 6414 tubes (black)
 1 - 6414 tube (gray)
 1 - 5965 tube

 Everything you need to enjoy for years to come and in pristine condition. All told, I have invested almost $4000 so you don't need to do anything except supply a nice set of headphones.
 (Pics to come, having trouble with my camera downloading)
 I am the 2nd owner - I bought from Audigon less than 2 months ago - son lost scholarship, so I am raising funds. This is the original listing - FYI - I have put less than 15 hours on it - he had about 150 hours on it. It has been checked - no issues at all - the transformer has been upgraded by previous owner - never ran hot for me.This one's a gem! No marks, scratches or blemishes, and you know how good these are. It has all the upgrades, as I have done every meaningful mod to make it the very best sounding headphone amp it can be. Simply put, you won't find a better one and you'll be elated with the sound and performance for years to come. It also has over a year left on the warranty transferable to you along with a wide assortment of tubes to personally tailor the sound. I just don't use it enough to justify keeping it anymore.Here's what you get:2 sets of SE inputs on backHigh/Low voltage bias adjustment switch for 6bl7 and 6bx7 tubesUpgraded Jensen audio cap for voltage regulationBlackgate cathode capsBlackgate output capsSoniccraft platinum teflon coupling capsUpgraded stepped attenuatorUpgraded power supply capsUpgraded "SLAM" adaptersAuto biasUpgraded large "SUPRA" transformerECC adapters for use with 7n7, 6414, 5687, 2c51/396a and other high gain tubesPlus a wide assortment of tubes:6 - 5687 tubes14 - 6bl7 tubes2 - 2c51 tungsol tubes1 - 2c51 sylvania tube2 - 12av7 tubes1 - 6sn7 tube2 - 7n7 tubes2 - 6414 tubes (black)1 - 6414 tube (gray)1 - 5965 tubeEverything you need to enjoy for years to come and in pristine condition. All told, I have invested almost $4000 so you don't need to do anything except supply a nice set of headphones.(Pics to come, having trouble with my camera downloading)Paypal adds 2.7%(Please only serious inquiries will be responded too).

 ---

 The key points of interest
 "High voltage option" puts 530V through 450V caps
 Supra transformer is wired wrong
 BlackGate never made caps over 350V, when amps fails, they see 530V.
 Sonicap Platinum is 400V, same issue with 530V B+.
 6BL7/6BX7 pull 3A heaters together, not sure what transformer is there to supply it - certainly not the one I had in mine.

 I'm really curious what this line means "_It has been checked - no issues at all - the transformer has been upgraded by previous owner - never ran hot for me_". Checked for what? Fleas?


----------



## sainttoad

You forgot to highlight the best part:

 "It also has over a year left on the warranty transferable to you"

 Good luck with that!


----------



## Pars

Quote:


 BlackGate never made caps over 350V 
 

BlackGate made 500V WV (550V surge) caps (WKZ series). Other than that, your correct. Amp sounds like a lot of fail to jump into... I wonder if it actually has the upgraded parts in it?


----------



## FallenAngel

Quote:


  Originally Posted by *Pars* /img/forum/go_quote.gif 
_BlackGate made 500V WV (550V surge) caps (WKZ series). Other than that, your correct. Amp sounds like a lot of fail to jump into... I wonder if it actually has the upgraded parts in it?_

 

Ah yes, the WKz series had some dual-section 2x 100uF / 500V caps that are usable as headphone output. Unfortunately, they haven't been available for some time, cost a small fortune and judging from the fun I had fitting the 2x100uF/500V JJ caps in there, are a VERY tight fit.


----------



## Elizabeth

I just bought that SinglePower MPX3off AudiogoN. I have used it for a few weeks.. I took the base off to have it run cooler with THREE 6BL7s in the top. The transformer case top (after five hours use) is pretty warm, but i can still keep my hand hard on it. The sides of the cases got just about as hot as I could stand keeping my hand hard on it with three 6BL7s in it after five hours use with the base still on. With the base off, the airflow really helps cooling. (the seller sent my about 20 6BL7s)
 i probably will drill a bunch of holes in the aluminum base bottom at the 'cool' input end and a bunch at the top side of the transformer end for cooling with the base back on.
 The inside of the MPX3 I bought is beautiful. All the wiring is well done, solder joints great, wiring great. no burning of any stuff.
 i am VERY pleased with owning such a NOTORIOUS headphone amp which I a sure will give me plenty of stuff to chat about for years to come.
 Thanks


----------



## Elizabeth

And PLEASE, do not start in on "how dangerous.. you must have it checked... stuff.
 I can read. And I have my own brain, and cann decide FOR MYSELF what "I" need, or don't need to do.
 Just a head's up for the furious posts I am sure will flow my way.


----------



## Webrider

Well I just opened my SP Extreme.
	

	
	
		
		

		
		
	


	




 and thanks to this forum I was not surprised when I saw what was waiting for me inside. A PPX3 Plus Rev A board that appears to be in good condition. I drilled out the PCB Board in 2 spots that appeared to be safe and was able to remove the transformer cover. The transformer looks like it is on its way to a melt down and will need to be replaced. One of the holes that I drilled was right up against the lead in the circuit board and I nicked the metal lead, I hope this is OK and am wondering what I should do to protect this area. I am a neophyte when it comes to electronics so I need to ask the wise ones hear on Head-Fi for any wisdom they can share. I would like to get my amp back up and running.
 Below are links to photos of the inside of my amp. Please provide feedback that will help me to repair the amp. 

 Regards,

SP Extreme Board on Flickr - Photo Sharing!
Inside #1 on Flickr - Photo Sharing!
Inside #2 on Flickr - Photo Sharing!
Bottom Right on Flickr - Photo Sharing!
Bottom Left on Flickr - Photo Sharing!
Top Left on Flickr - Photo Sharing!
Top Right on Flickr - Photo Sharing!
Holes to remove transformer Cover on Flickr - Photo Sharing!
Transformer pic #1 on Flickr - Photo Sharing!
Transformer pic # 2 on Flickr - Photo Sharing!


----------



## Skylab

That transformer is definitely cooked. No doubt. You will need to find someone who will replace the transformer and inspect the rest of the amp for issues. Lots of people have used Bolder, so you might see what his current backlog is like. 

 After having the ElectraPrint transformer installed on mine, along with some new resisters, I have had zero issues and been very happy with the restored amp. But these things almost all require fixing.


----------



## FallenAngel

Quote:


  Originally Posted by *Elizabeth* /img/forum/go_quote.gif 
_I just bought that SinglePower MPX3off AudiogoN. I have used it for a few weeks.. I took the base off to have it run cooler with THREE 6BL7s in the top. The transformer case top (after five hours use) is pretty warm, but i can still keep my hand hard on it. The sides of the cases got just about as hot as I could stand keeping my hand hard on it with three 6BL7s in it after five hours use with the base still on. With the base off, the airflow really helps cooling. (the seller sent my about 20 6BL7s)
 i probably will drill a bunch of holes in the aluminum base bottom at the 'cool' input end and a bunch at the top side of the transformer end for cooling with the base back on.
 The inside of the MPX3 I bought is beautiful. All the wiring is well done, solder joints great, wiring great. no burning of any stuff.
 i am VERY pleased with owning such a NOTORIOUS headphone amp which I a sure will give me plenty of stuff to chat about for years to come.
 Thanks_

 

 Quote:


  Originally Posted by *Elizabeth* /img/forum/go_quote.gif 
_And PLEASE, do not start in on "how dangerous.. you must have it checked... stuff.
 I can read. And I have my own brain, and cann decide FOR MYSELF what "I" need, or don't need to do.
 Just a head's up for the furious posts I am sure will flow my way._

 

Really now... 3x 6BL7s... running 4.5A heaters combined... through 3A rated diodes and likely off a power transformer that has 3A 6.3A windings. Well, good luck with that.


----------



## FallenAngel

Simple - here is my experience with the MPX3 and 6BL7 so I wouldn't say it's rhetoric.


----------



## n_maher

Folks, keep it civil or there will be consequences. Fighting, bickering and name calling is of no help to people with damaged or dangerous goods and there's enough evidence at this point to suspect that most, if not all units require repair.


----------



## Vincent01

This is a very useful information and I would like to thank N_maher for being a good citizen. My friend owned Singlepower Extreme and as of now, it is still doing okay, so far. Maybe, there was just some singlepower that was not made coherently. Or maybe, the owner of any amps should be always aware and informative regarding their amps.


----------



## Webrider

I had my tech complete the transformer swap and check over the rest of the amp. It received a clean bill of health. I went with the Electra Print transformer and I love the way it looks sitting on an angle parallel to the tubes and exposed for the entire world to see. I allowed the amp to burn in for the last month. The improvement in sound quality was very evident from its former condition. It is dead silent and neutral; all I hear now is the music as it should be. I will definitely be keeping this amp for a long time, now that the sound quality has improved. I was hesitant to change out the transformer, as the sound quality was good as far as I could tell. However, when I cracked open the case and removed the transformer cover I found a transformer that was beginning to fry and on its way to an early death. Therefore, anyone who has hesitated to make the repairs to their own amp thinking there is nothing wrong, you will not be disappointed once you hear the improvement in SQ and know that your SP Extreme is now safe to use. Thank you to all of those who provided input on the repairs for their own SP Extreme.  Thank you to n_maher, kevin gilmore, Bolder, mourip and Skylab for your help enabling me to repair mine. Your advice helped me make the correct decisions when deciding how to turn my Singlepower Extreme into a Head-Fi Extreme.


----------



## Webrider

Photos of the modified SP Extreme now a Head-Fi Extreme


----------



## mrarroyo

Nice looking unit you have there Webrider, enjoy it.


----------



## Webrider

Thanks, I am enjoying it every chance I get. Its definitely worth the effort and cost to repair and upgrade these amps.


----------



## Happy Camper

These threads should be stickied in the full amp section again.


----------



## John D.

Quote: 





bolder said:


> Another alternative might be to use a transformer cover. If you have the room, these might work for you. At least they are reasonably priced.


 
  Help needed. Does anyone know of other sources for a transformer cover on my stock Extreme?
  The link above is in China, and I would like to deal with a U.S. company, if possible.
  I will be putting in the edcor transformer mentioned in this thread.
  Any help is much appreciated.
   
  Thanks,
  John D.


----------



## Skylab

You can get a nice one from ElectraPrint.


----------



## John D.

Quote: 





skylab said:


> You can get a nice one from ElectraPrint.


 
  After being in contact with Jack about purchasing one his transformers, and being told he no longer makes and sells them,
  I'm not too sure he would still be selling covers for them. He was my first choice for a transformer. His website states effective
  immediately we no longer build power transformers and power chokes. He told me that he can't afford the price of copper, said
  the Chinese are driving up the price.


----------



## Skylab

Wow.  Bummer. Did not know that. Sorry.


----------



## spritzer

Some of these might work.


----------



## liamstrain

Edcor might have something too. 
  http://www.edcorusa.com/Products.aspx
   
  edit: I see you are already working with them on the transformer, and it looks like they only provide unpainted steel end bells for DIY.


----------



## John D.

Quote: 





liamstrain said:


> Edcor might have something too.
> http://www.edcorusa.com/Products.aspx
> 
> edit: I see you are already working with them on the transformer, and it looks like they only provide unpainted steel end bells for DIY.


 

 Yes, I already have the edcor transformer (painted blue bells), it took about 3 weeks to get after placing the order.


----------



## John D.

Quote: 





spritzer said:


> Some of these might work.


 
  Thanks for the link, went ahead and ordered from them. Attached are some photos of before and after my amp was fixed.

  


   
  This amp sounds better now than it ever has. !!!!!!!!!!!!!!!!!!!!!


----------



## kevin gilmore

With the new transformer you might want to adjust the value of the resistor to set the tubes at 6.3 VDC
  after it has been on for 10 minutes.


----------



## FraGGleR

Sorry to resurrect an older thread about a sensitive company, but at this point in the game, is it pretty much guaranteed that a Singlepower that was built in the last couple years will most likely need inspection/work?  I heard mrarroyo's several years ago and it sounded incredible to my ears.  There are several currently available at prices that surprised me and I have really wanted to try tubes, but I don't think I could afford the repairs if necessary.  Am I better off going with an amp with a better reputation?


----------



## Hooster

Quote:  





> There are several currently available at prices that surprised me


 
   
  You already know this, but you get what you pay for. If you just want to play around and experiment it might be great. If I wanted to a component that I could buy and forget about and expect day in and day out reliability from I would look elsewhere. You are however not me and as they say, YMMV.


----------



## mrarroyo

I would try a different manufacturer unless you are buying a rebuilt Singlepower by a know repair shop. I still have my Singlepower MPX3 SE Slam that has been made safe and I love its sound, you may want to look into Mapletree amps by Dr. Lloyd or if you want to spend the moola Red Wine Audio amps.


----------



## spritzer

Claims that the earlier SinglePower amps are better built than the later ones aren't based in reality, even the first ones have serious issues.  Granted, Mikhail wasn't quite as mad in the beginning so no +500VDC on normal 6SN7's fed through a 117V rated switch as the "HV option" or other crap like that.


----------



## FraGGleR

Thanks everyone.  I think I will scratch two itches at once (tubes and DIY) and try a Bottlehead Crack kit, maybe a Bijou.  Added bonus of learning more about how tubes work by DIY.


----------



## Hooster

Quote: 





fraggler said:


> Thanks everyone.  I think I will scratch two itches at once (tubes and DIY) and try a Bottlehead Crack kit, maybe a Bijou.  Added bonus of learning more about how tubes work by DIY.


 
   
  Sounds like a good plan, enjoy.


----------



## P+D-MI

Of the singlepower amps that I owned or heard, you can do better for the money. imo.


----------



## Inter

I have a Singlepower MPX3-slam and I was wondering if anyone could tell if this is one of the safe ones? Never had much trouble with it, except for some noise in the right channel every now and then. It gets quite hot but I've used it for years..


----------



## spritzer

We would need detailed internal pics to know if it is safe or not.


----------



## Inter

Ok. Thanks for the input. I'm not sure if I am proficient enough to get the lid off. Not seen these particular screws before..


----------



## spritzer

They are hex (or Allen keys) and a small imperial size.  To make matters worse the screws are glued in place as Mikhail didn't want anybody to see what was inside.


----------



## kevin gilmore

drilling out the screws is lots of fun. They are hardened steel and in addition
  to everything else, they rust.


----------



## DefQon

How well do the old MP3X SE with Supra upgrades fair up against today's tube amp's within $1k?


----------



## spritzer

If it has been fixed by somebody who knows what he's doing then it's a good amp.  If it's still stock and/or gone over "by my tube tech" or some such nonsense, stay away.


----------



## DefQon

Quote: 





spritzer said:


> If it has been fixed by somebody who knows what he's doing then it's a good amp.  If it's still stock and/or gone over "by my tube tech" or some such nonsense, stay away.


 
   
  Thanks for that, there is one listing in the F/S section which I assume is a slightly later model (2006) by Mikhail as it comes with the HV option and supposedly it's been working fine since the user bought it back 6 years ago. Although I have no experience fixing up Single power amp's, I'm willing to open it up and post pictures here for you guys to see if part's have been wired up within spec or properly. I feel at worse it will be needing a rebuild or such.


----------



## spritzer

Stay far away from any amp with the HV option.  They are the worst I've seen, crucial parts under spec but driven very hard and when something goes wrong the headphones are toast and there might be some injury to the user as well. 
   
  I would never pay more than 100$+shipping for anything Single Power as it takes a lot of work and money to get these right.  In many cases it just easier to throw everything away and start anew.


----------



## DefQon

Quote: 





spritzer said:


> Stay far away from any amp with the HV option.  They are the worst I've seen, crucial parts under spec but driven very hard and when something goes wrong the headphones are toast and there might be some injury to the user as well.
> 
> I would never pay more than 100$+shipping for anything Single Power as it takes a lot of work and money to get these right.  In many cases it just easier to throw everything away and start anew.


 
  Ok thanks for the suggestion, I think you have a point. Just not worth the risk, time, effort and money involved.


----------



## Boom Shaka Laka

That's a Q I've been wondering lately, have you drawn any conclusions yet? If I get to A/B my SE Slam I'll post findings.

Cheers, 
SL


----------



## Boom Shaka Laka

Oops, forgot to include quote I'm replying to:



defqon said:


> How well do the old MP3X SE with Supra upgrades fair up against today's tube amp's within $1k?




That's a Q I've been wondering lately, have you drawn any conclusions yet? If I get to A/B my SE Slam I'll post findings.

Cheers,
SL


----------



## Boom Shaka Laka

inter said:


> I have a Singlepower MPX3-slam and I was wondering if anyone could te
> 
> 
> ll if this is one of the safe ones? Never had much trouble with it, except for some noise in the right channel every now and then. It gets quite hot but I've used it for years..





Bought mine from previous owner in '07 who had it in '06, I would have to open up to get s/n. Nevertheless, mine sounds pretty good and switched to a Goldpoint attenuator. I should feel lucky by the results of Singlepower lately. I wonder if anyone on the boards lives in Denver and has stopped by Mikhail's lately.


----------



## DefQon

Hi
  
 Nah I haven't heard or bought the Slam, it's risk I'm not willing to take given the amount of time and effort you'd need to sink in to get it fixed.
  
 Would like to hear your findings though.


----------



## thathertz

Anyone out there still running a Singlepower amp? I'm still using mine (Singlepower Extreme Platinum - no repairs/modifications applied) and it's awesome.
  
 C'mon guys, lets have some stories.....


----------



## DefQon

Post pictures of your Singlepower? I haven't seen all of the amp products Single power had back in the day, so many Extreme's.


----------



## Skylab

thathertz said:


> Anyone out there still running a Singlepower amp? I'm still using mine (Singlepower Extreme Platinum - no repairs/modifications applied) and it's awesome.
> 
> C'mon guys, lets have some stories.....


 
  
 The "Platinum" didn't have the same transformer problem/danger as the regular Extreme?


----------



## John D.

thathertz said:


> Anyone out there still running a Singlepower amp? I'm still using mine (Singlepower Extreme Platinum - no repairs/modifications applied) and it's awesome.
> 
> C'mon guys, lets have some stories.....


 

 After changing out the transformer, my Extreme is in use almost everyday with no issues. I plan on keeping it. Pictures of my Extreme are still in recent images.


----------



## tagosaku

thathertz said:


> Anyone out there still running a Singlepower amp? I'm still using mine (Singlepower Extreme Platinum - no repairs/modifications applied) and it's awesome.
> 
> C'mon guys, lets have some stories.....


 
  
 My MPX3 is working fine


----------



## augustwest

My MPX3 was working fine until last week when it stopped working. No drama, no loud pop, no burning smell, no smoke, it just stopped and went cold mid-CD. I'm now trying to learn what is wrong with it and if it will be repair, or replace.


----------



## thathertz

augustwest said:


> My MPX3 was working fine until last week when it stopped working. No drama, no loud pop, no burning smell, no smoke, it just stopped and went cold mid-CD. I'm now trying to learn what is wrong with it and if it will be repair, or replace.


 
  
 Sh**. I hope you can get it sorted. Did you try replacement tubes?


----------



## kramer5150

My darkvoice did that once... It was just the fuse that popped. Not sure what caused it


----------



## augustwest

_"Sh**. I hope you can get it sorted. Did you try replacement tubes?"_
  
  
_"My darkvoice did that once... It was just the fuse that popped. Not sure what caused it"_
  
  
 I check the fuse and it was burnt. Replaced the fuse and it immediately burnt again. The amp is currently with someone who repairs guitar amps and builds the custom _Red Jones Amps._ If you play electric guitar, or just appreciate fine craftsmanship you might want to check these amps out < www.*redjonesamp*lification.com >. They are a thing of beauty.
  
 Depending on what is found, I hope to have the amp back soon. Sure am missing some quality sound.


----------



## MikoLayer

I am still, well "was" using my PPX3 I bought from another head-fier circa Aug-Sep 2004. I tried to search the thread for PPX and read many thoughtful posts by Dr. Gilmore, and still unsure if my unit would need extensive repairs for safe operation. Would I be wrong to assume most serious issues were with the Extreme and some of the higher end units SP sold? Come to think of it, having my unit repaired and upgraded by Boulder had been a plan for a while, I just never got around to do it. 
  
 The last time I powered on the amp was about 2 years ago and it worked fine back then. Not entirely sure what upgrades it had as I've lost all my transaction PMs with the previous owner; I do know it doesn't have the slam upgrade/adapters, just the standard 6cg7 deal with two headphone outputs as an option.


----------



## mstorie

mikolayer said:


> I am still, well "was" using my PPX3 I bought from another head-fier circa Aug-Sep 2004. I tried to search the thread for PPX and read many thoughtful posts by Dr. Gilmore, and still unsure if my unit would need extensive repairs for safe operation. Would I be wrong to assume most serious issues were with the Extreme and some of the higher end units SP sold? Come to think of it, having my unit repaired and upgraded by Boulder had been a plan for a while, I just never got around to do it.
> 
> The last time I powered on the amp was about 2 years ago and it worked fine back then. Not entirely sure what upgrades it had as I've lost all my transaction PMs with the previous owner; I do know it doesn't have the slam upgrade/adapters, just the standard 6cg7 deal with two headphone outputs as an option.


 
 No way to know unless it's opened up and looked at by a tech who can service/repair/upgrade the amp. I listen to a PPX3 SLAM and an MPX3 each week, although not for long hours or days at a time. Seems like they were less susceptible, but not immune to problems. Earlier/simpler amps were for the most part properly spec'd and built, so a straight PPX3 "should be fine", but no guarantees here...
  
 Wonder what happened to Augustwest? You get it fixed bro?


----------



## wendyKL

This guy still around?


----------

