kevin gilmore

You obviously need a pair of the krell master reference amps. For a combined weight of about 700 lbs for a stereo unit.

And none of that has anything to do with water damage. The electrolytic caps in the power supply of the amp are 25+ years old and need replacment. All Mcintosh switches get dirty and scratchy, especially the volume pot. The light bulbs go out all the time, and are very easily replaced. But evidently that is the cost of decent labor these days. Personally i think it is high, and if you send the stuff back to the factory they will do a better job and be a bit cheaper, plus come with a warranty. This is great classic Mcintosh stuff.

Nope you were not paying attention. Ray's hr2 is a dual power supply dc coupled unit. no caps in the signal path. graham slee is same exact circuit with only one power supply and input and output caps. Lots of open loop gain and what amounts to a class B output buffer.

I can think of lots of 70's solid state gear worth way more than $2k. This isn't in that league...

OH no... Its a ray samuels HR2 built with a single ended power supply, cap input, cap output... Massive piece of shit. DC coupled version on headwize someplace ray's is built a bit better however. http://www.raysamuelsaudio.com/products/hr-2

99% chance it works as is. That stuff was built like a tank. If its tubes it is even easier to clean up. I've seen mc75's submerged under water that when left to dry work to spec. However the chassis then was steel and that will rust, so you need to attend to that pretty quickly. If its tube stuff its definitely worth fixing. Even the solid state stuff from back then was pretty good. MC26 preamp, MC6100 power amp...

I did that with the Uberamp... Much better idea is Ethylene glycol. Then when you spring a leak, you really do have a fucking mess everywhere. Water and high voltage. Great idea... Did i mention that i'm using my extreme with an ipod and hd600's in the master bathroom. Seriously...

You ever see a singlepower product leave the factory with heatsinks??? And not the ones that one guy put on his pencil amplifier to keep it from getting so hot it was able to boil water. 60 watts of heatsink is twice what you put on a dynahi No fear, i've found a cheap transformer that fixes most of that problem.

Well it looks like you are ok as you have the real thing. Maybe even custom. So you are fine although at some point you have to deal with the overheated resistor. As far as voltron and tyson, it turns out mikhail had it exactly backwards. For low impedance loads you want more current, not more voltage. Trouble with most and probably all of those is the 500 volt power supply rail. By the time you turn up the current on the output tubes for maximum power and linearity the regulator device is dishing out 30 watts. (60 watts in voltron's case) And clearly without any kind of heatsink that big, things are going to get very warm very fast.

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.