kevin gilmore

The output stage is all by itself and has a capacitor coupled input to that stage. So unless both output tubes short plate to cathode, its pretty unlikely that any damage to the headphones can happen. But anything can happen. protection circuits are a good idea, but the one on the srm007t was way to sensitive. Obviously since there is going to be a version 2 of the electra, craig says the new autobias front end fixes the distortion problem. I don't believe that. Not with 6sn7 tubes anyway. GSX2 sounds absolutely wonderful on my hd800. One of my all time favorites.

no matter how well the input tube sections are matched to each other, over a period of time, usually less than 6 weeks, the thing drifts so much there is significant distortion. stupid fucking design. and the output tapped inductor is not sufficient for wide band audio reproduction. Too small a core and not enough wire.

Mikhail... All singlepower extremes burned up their transformers. Once you put a real transformer on it, sounds great. ES1 and ES2, output tubes deliberately biased at -160 volts causing maximum VPSS voltage swing to be 800v. Very grim. all high voltage versions of the dynamic amps. major stupidity. singlepower squarewave. no heatsinks, burns up. But the fixed version is kickass for cheap. Rudistor silver plated copper wire reinforcement of hand etched circuit boards. major clusterfuck boxes of boxes of boxes. one of which is a resistor (current source) in a box with a fan headroom all the early stuff was built well and sounded like crap. very poor performance. (sorry tyll) sennheiser hev60 what a horrible design and their new $2k thing is a poor sounding piece of crap cavalli liquid fire, take a standard circuit, replace front end with tubes, output stage with mosfets. Then deliberately limit the available output current. Major clusterfuck liquid gold take a standard circuit and shrink both power supply voltages and number of output devices. and claim that it is true balanced. but to make sure, add real piece of crap buf634 driving drv134 to make unbalanced into balanced to drive it.

Both of them seem to be GES clones. The second one is 6fq7 as the output tubes. Not sure what the 7 pin output tubes are.

At least 200 phone calls with Mikhail trying to get him to see the errors of his ways. We all know how that turned out. There is a lot of money behind cavalli and they are going to succeed by trying to do every thing in the ray samuels playbook, plus lots of things in the advanced edition. Cavailli has taken paid for shills to a new level. Ray would be proud.

What position are you going to put the 12bh7 in? May have to change the resistors in te cathode bias a bit. The megaton has lower distortion at higher levels than the Electra or the Wes. In fact it's lower distortion and a much wider Frequency response than some of the solid state amps out there.

Yep the real deal. I have 2 rolls left, about 3000 feet total. Great stuff, massively thick silver plating on copper with Teflon insulation. The date on the roll really is 1955. Very heavy compared to current stuff. Not the crap whiplash was using.

Teflon wires for the win. Justin is using Teflon wire now!

the ultimate in insanity is a pair of krell master reference monoblocks driving stax headphones. or he6's, your choice.

Even the kgsshv boards built by Hennyo were repairable. The lack of decent connectors between the power supply and The amp board almost guarantees damage every time you Have to take the thing apart to fix it because you have to Unsolder the wires from the top and clean the holes later

Making it harder to fix makes repairs a profit center

and those ultra cheap ids connectors for the 2 pin things. I hate those. actually it was pointed out to me that those are not extrusions but just flat pieces with angle brackets. So REALLY cheap.

also notice that the whole case is aluminum extrusions. So new chassis again. at least the tube is much better and lower distortion and wider frequency response than the mosfet as the voltage gain stage. Now the output stage that sucks all the power is completely useless. only one transformer now so there had better be a delay circuit for the high voltage otherwise the tubes are not going to last very long.

definitely moar better.

I can post pics of the original. And the burned circuit boards that resulted from no heatsinks because the bias was 4 diodes and all over the map. This really is the original design. With a real bias generator and a dc servo because you can't get those output caps anymore, and why would you want them anyway.

yes 10ma in the output stage. That's 80% of the tube rating. you can use the other parts, but they are not as temperature stable.

its kind of funny that something that started out as a $200 amp turned into something >$5k

That is right depending on the second stage zeners. If unreg voltage is at least 35 you will be fine

You sure they are 6s4... I will fix schematic later. Hard to tell the difference between 6s4 and 6973

yep, the input fet has been fixed. also, next version of the kgsshvk board has it fixed too. (at least I think its fixed, please check) hv transformer is going to be lower voltages. best idea to have a separate filament transformer and time delay. current power supply board works fine with the resistors adjusted for 400v which means the unregulated voltages should be about 465v. will post newest picture, same name in a few minutes

actually birgir is right, its worse, not better. http://gilmore.chem.northwestern.edu/llmk3.pdf

same power supply, just adjusted for 400v

as far as I know the portable is not an electrostatic amp. I have a great design for a portable electrostatic amp. Every time I try to get someone to build me the switching power supply transformer, they either cannot deliver, or what they deliver is so low in efficiency that it would eat batteries way to fast. What I really want is stacked printed coils on kapton. anyway, the stax mafia does not let grass grow under their feet. http://gilmore.chem.northwestern.edu/kgst.jpg solid state/tube hybrid done right, and actually pretty cheap.

enough people have been asking for this, we finally decided to do it. It was easy from the current layout. Best to stick with +/-400v power supplies http://gilmore.chem.northwestern.edu/kgst.jpg

you know that for a great design, all you need is a voltmeter.