kevin gilmore

OK, so a picture of the insides of guzziguys amp would help. Reason is that the one of the two companies probably used has different wiring colors on the transformer wires. Pictures of the area around the transformer. Also looking for transformer wires not used (like the 5v ct winding on the hammonds) I'm working with someone that is trying to fix tyson's amplifier right now. You betcha, mikhail fail all over the place. The B+ on that thing with 6bl7's is 500 volts. At 30ma. Into a 25 ohm load it puts out only 2.5 milliwatts before clipping. By the way, on that unit the output caps are running 50 volts over spec. On voltron's amp the spec on the output caps is 160 volts (pretty sure on this one) which means he should never EVER go more than 2 x 75 volt gas tubes (well 4 total). I'm pretty serious about this one. Otherwise the posibility of expensive headphones going poof...

I've just looked thru all the plitron standard product and there is no standard part that comes even close to the required power and voltage requirements. So if it really is a plitron, it would have to be a custom thing. Something like 120vac output at .5 amp, and 6.3vac at 10 amps.

You just think that it is a plitron transformer because you have been told it is. Given the events of the recent couple of months, how do you really know unless you pop the cover and look. plitron transformers, every one i have ever seen going way back are all toroids and won't fit into the square box. So if you still have the 4 inch x 4 inch square box there is no way a plitron toroid is going to fit in there. If you have the round cover then there is a good chance you really have the right transformer. Then there is the issue of what particular model number it is. Here is a big hint. Nothing mikhail has ever done that i have seen so far has custom transformers, everything is a stock model. His line that he had the transformers custom made is pure bullshit. If the transformer runs so hot that you can't touch it after it has been on for an hour, it is likely that sooner or later the transformer will let go. When that happens a custom transformer is about $107. But then it ends up looking like mine does now instead of what it used to look like.

My personal amp is a ppx3 extreme. Back then mikhail built about 50 mpx3's and ppx3's and was unable to sell them. So he tore them apart and rebuilt them as extremes. Including the completely underpowered transformer. There are only 3 different chassis sizes, and 2 different circuits total. Plus all the custom stupidity. (dynamic amps only) My tube power supply design was such that it used existing tube socket holes, and did not require any chassis work. I can certainly build all tube power supplies that regulate to a fraction of a volt. Basically copies of the old tektronix stuff. Requires very custom transformers with lots of isolated taps. Would not fit in that box.

latest singlepower clusterfuck here Supra Schematic? - Head-Fi: Covering Headphones, Earphones and Portable Audio and a smoked singlepower supra extreme slam se with pictures soon. If the person that is going to fix this is as good as i hope they will be, then maybe we can find a way to get him to drive over to mikhail's with a truck and pick up all the dead stuff and then charge people to fix it. He is only 75 miles away or so...

Corporate keys for windows 7 enterprise hit my mailbox over the weekend, so things must be close.

I was kidding. I realize how much work some of these things are. I thought it was going to be an easy fix. Boy was i wrong. Then again the ES1 repair thing went thru 3 rev's to get it perfect. And each rev was more work. Nate only got half of the singlepower experience. Years later he will be left wanting more...

you gave up too soon

Ironbut == Singlepower Service and Repair West Coast Division! Someone has to do it.

Thats only if it dies 7 times and is resold to 6 more different people. And i do expect that it was just a few parts that were the cause of the problem. Cold solder joints, probably all over the place... Wasn't worth the shipping charges both ways... And i did not expect that there was going to be anything wrong in the amp chassis except for a few bad solder joints and shit sockets.

Very sweet that it is working again. Would like to know which parts he swapped out, so that you can stock up for next time. And i did not have to touch it. The best part of all. The ES1's are repairable too, just a fuckload of work.

Actually a bigass mosfet on a heatsink might definitely sound pretty good and neutral. I'll have a chance to try this in a few weeks. Any 200 volt N channel MOSFET good for a couple of amps on a heatsink for 5 watts should work great. A whole pile of renasys or IR parts...

The pin on the 1704 lifted going directly to the opamp and caddok i/v feedback resistor is done that way to avoid any possible extra capacitance on the dac output wire. I have seen lots of high impedance circuits built this way for a minimum of interactions from circuit board materials. Not really a bad thing. There were regular dip versions of the 1704 available that probably plugged in directly into the socket, but still the one wire would have been lifted and soldered the same way. Definitely not enough parts to be balanced with 4 dacs. After the I/V conversion is a 4 pole active filter with a pair of 627's. Then the 712 as the phase inverter, and another pair of 627's as the output amplifiers. Standard sort of thing. Open up the RF can and lets see how good the build quality really is. The metal can just pulls up. For its time it is built reasonable. Definitely not crummy diy. But not 4 layer shielded circuit board either.

One other thing, i forgot to mention is the 5k resistors are now actually 2k on my prototype so as to match the gain between the two different feedback types.

SJ2 NOT necessary. EXCEPT you have to flip pins 1 and 2 of the feedback jumper connector. The inverting input needs to be the middle pin.

I'm liking it just fine with 2 ohm emitter resistors. Vbe multiplier just fine with 10k resistors and 20k pot. a resistor in series with the 20k pot is a really good idea. I'm not using the input bias trimmers. As long as the voltage at the output of the opamp is less than +/-2V no need to trim. working on a custom fully machined heatsink now.

NO. And here is why. Its a whole bunch of work, and the amount of work depends on which of the 7 known different types it is. The worst being the circuit board version that neil has. The early circuit board versions are a lot easier. The schematics have grown to a complete re-design of the power supply, and some significant modifications to the amp which include replacing the 4 pots with 8 pots, and dealing with the coupling caps. latest schematics here. http://gilmore.chem.northwestern.edu/singlehoures1fix.jpg but really the bass really comes alive when you change out the .01 caps with .05 caps. http://gilmore.chem.northwestern.edu/singlehoures1psfix.jpg but really a KGBH regulated supply is a much better idea. So the parts list is 8 x 10 turn really good pots with 10 turn locking dials ($35 each) (bourns plus clarostat knob) set of 4 amphenol or equivalent plugs $150 for the real thing, or half that for the chinese copy BH power supply board with all parts (may or may not fit depending on chassis) extra filament transformer extra C- transformer and parts... And 20 or more hours of labor. What you end up with is very stunning. And how you adjust it is measure voltage between Tp1 and TP2 and adjust rv1 for zero volts, then measure TP1 to ground and adjust rv4 for 200 volts. Then adjust rv3 for zero volts to ground at TP3 and rv4 for zero volts to ground at TP4.

I don't know where the production boards are at in the production stage, but if possible it would be nice to move the two different feedback methods to the top side of the board with a 3 pin user configurable jumper... requested by icarium...

But that was when there were only a total of 4 fets. and its still the same 300ma and 18 watts... So i doubled the number of fets and halved the current per fet.

So i think people are pushing this thing way too hard. The design goal is 75 ma per fet times 4 fets (1 x p channel and 1 x n channel) For a total power supply of 300ma at 60 volts which is 18 watts. My heatsinks get to about 96F after being on for an hour or more. The fets can certainly take way more than this, and the board will happily drive them that way, but you have to take the fets of the board and heatsink like crazy. Then you should be able to get to about 50 watts pure class A into 8 ohms...

I was just teasing. I sure hope she does not find out about this. Yep she is a full fledged SOFTWARE ENGINEER.

I'm about 95% done stuffing the board marc sent me, this is definitely NOT a beginner project. I'll be machining up some custom brackets in the next couple of days. If anyone sells boards to -=her=- i will hunt them down and kill them. Seriously a person with her skills has no chance at this thing.

May the glow of your new ES1 lightup the day.

Hey at the time i was one of those wippersnappers that did (god forbid) "sand" The art performed by those tube wizards was amazing. Especially the stuff that zenith did for the military. There were all these rules that everyone paid attention to back then, like the fact that all passive components had to be secured at both ends. All wiring had to be tied together every inch with a loop and continue... None of mikhail's air mounting of components. Or mounting a component at one end and soldering unsecured wire to the other. That kind of crap would never have been tolerated. Go and look inside any 50 year old tektronix tube scope and see how the stuff was built to last forever. Most people don't know this, but image intensifiers was a zenith invention. The BHSE supply will supply +400, -400, one of the 2 filament supplies and the bias supply. And it will certainly fit in that box. To finish the thing correctly you need one more filament supply (a transformer is just fine) and a small C- supply, plus new umbilical cables and connectors. Then in the amp box you gotta get brutal. Unsolder every fucking piece of wire. Get the board out there. Take a dremel tool and cut away circuit lands to seperate the two filament sections. Then modify to take the 4 new output tube bias pots. Then replace the 50k pots with 5k pots and hide those inside somewhere... Use 10 turn pots and hopefully they will fit in place of the old ones on the front panel (pretty sure they will fit if they are at least .9 inch center to center). Use really cool locking 10 turn turns counting dials. And when you get done it will work forever. But an all tube power supply would be way cool, and a bunch more work. And i forgot the best part. Take the fucking orange drop cap out from being in series with the audio note cap that is already rated for voltage.

Lots of people think they can design electrostatic amps. Lots of people have failed too. My guess is that there is a new amp destined for failure soon. The original circuit works just fine if built correctly.