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The Single Power ES-1/2 repair and restoration thread - Page 3

post #31 of 145
7/4/09 at 5:33pm
Quote:
Originally Posted by immtbiker View Post
I was chastised for years for warning people about Singlepower and it's immoral path to hell, some saying that I had an agenda.
Sounds like me and Michael Jackson.
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post #32 of 145
7/4/09 at 9:59pm
Quote:
Originally Posted by earwicker7 View Post
Sounds like me and Michael Jackson.
Let's try and keep this on topic, shall we? The point here is to help owners who are stuck with non or malfunctioning equipment. There isn't much funny about it.
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post #33 of 145
7/4/09 at 10:39pm
Quote:
Originally Posted by jgazal View Post
I think it is almost impossible to moderate the avalanche of information available at head-fi (that happens on every internet forum).

If people were here reading excellent reports from other users, moderators were not obliged to employ independent electronic engineers to test each and every amplifier.

I presume this role is assigned to an independent product safety certification organization (such as http://www.ul.com), Federal Communications Commission (About the Federal Communications Commission) or at least U.S. Consumer Product Safety Commission (CPSC Home Page - About Tab).

Just observe any electronic equipment in your house and you are going to see that all of them have several certifications and notes of compliance with international standards.

Having said that, I think moderators should not in any way criticize the noble attitude of the author of this thread.

Although the vast majority of head-fi users will not fully understand how an electronic circuit works, neither learn how to repair it or deal with high voltages, it helps to put trust again in the user related information head-fi makes possible to transmit.

All in all, these are the cons and pros of free speech...
There are few ratings and listings as most of this gear is hobby built. (I am a ________ builder because I say I am) About the only thing that is listed is the power cord. Not all of course but a large amount. With people buying and selling from all corners of the world, there is often no advanced testing or safety review of design other than our member's experiences. Thanks guys for your continued efforts.

Buyer beware at any cost.
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post #34 of 145
7/6/09 at 9:44pm
Really depressing to read all of this, since I really liked and trusted Mikhail. But, when I first heard an ES-1 at a National Meet, a couple of years ago, using my HE90, I was really disappointed. It didn't sound nearly as good as an HEV90, and not even as good as my relatively inexpensive McAlister.
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post #35 of 145
7/7/09 at 11:58am
Thread Starter 
I must say I was very underwhelmed when I first fired up the ES-1. Now it was different in many ways from the original SP unit with separated filaments, regulated PSU, proper bias supply plus I trimmed away a lot of extra stuff which wasn't necessary so that could account for something. I found the sound to be mushy, soft and lacking the explosive dynamics the circuits should be able to pull off. Now none of the ES amps had the ability to reach their full output swing and it's only now that I've installed a fix (more of a design then a fix though) that the amp is coming alive. It can't quite match the bass control of the BH but it's no slouch.

When I got this amp all the output tubes were sitting at -109VDC to -115VDC which severely limits the output capability of the amp. Now that it's running at 0VDC things are quite a bit better. I'm not out of the woods yet since the left channel is still lower in volume then the right, which has to be tracked down and fixed, plus there are some more modifications waiting to be implemented.
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post #36 of 145
7/8/09 at 2:26am
Looking forward to the true results posts....
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post #37 of 145
7/8/09 at 4:06am
Wow - I never would have been able to understand what was wrong and get it working - you are to be commended.
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post #38 of 145
7/8/09 at 11:12am
Thread Starter 
I certainly couldn't have done this without Dr. Gilmore. Just yesterday he sent me a new twist to the circuit which means lower distortion (the amp has audible distortion at silly levels into the SR-007 with these tubes) and the ability to match the circuit to any input tubes used. Now I've just got to find a way to cram yet another pot onto the top panel plus some more test points...
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post #39 of 145
7/8/09 at 1:04pm
Nice spritzer. You are testing the amp with the OII right? When I had the ES-1 I thought it was pretty dynamics sounding with my HE90.
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post #40 of 145
7/8/09 at 5:15pm
Thread Starter 
I'm testing it with what phones I have at hand which are two variations on the SR-007, a Lambda Pro and the SR-003. The L-Pro's are quick to pick up on any bias issues and the SR-003 can track down hum better then anything else around.

I'm not surprised that the HE90 sounded dynamic since who knows what bias voltage they were fed and they aren't that hard to drive in the first place. In stock form this amp doesn't have more voltage swing then the Stax tube amps but obviously has more power on tap.
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post #41 of 145
7/8/09 at 8:27pm
Did that thing really cost 3999$? What about never buy anything before seeing what there's inside?
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post #42 of 145
7/8/09 at 8:30pm
With options as shown in the pictures it was close to $10k, see price sheet on
page 1. Plus shipping back and forth from colorado to south africa at least 4 times.
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post #43 of 145
7/8/09 at 8:46pm
If I wanted to open up my Supra XLR to take photos of the circuit layout - would I need to take any specific cautions?

Take out tubes, un-plug from wall, _________ ?

I am defiantly interested in documenting older work.
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post #44 of 145
7/8/09 at 9:22pm
This is an eye popping thread. I'd heard talk on problems here with these amps, but never actually understood how bad things were. Just shocking really. Look forward to more updates on this.

Ooh look, 666 posts.
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post #45 of 145
7/8/09 at 10:20pm
The shock of how seriously bad the SP saga was only truly hit home when I saw this thread. Commendations to spritzer for the effort in documenting and sharing the info on this amp.
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