kevin gilmore

The on board version can only handle so much power because of the heatsink size. The default is 5ma, which at 450V is 9 watts total for the output stage which is 2.25 watts per output device. The off board version is limited by only 2 things, the size of the heatsink and the maximum amount of power the output devices can handle. So yours is 14ma which is 25 watts per channel. The effect of the higher current is to extend the high frequency response well past 50khz. So the amp will definitely sound different. The choice of resistors will likely not make a change that you can ever hear. Except that a few of the trendy and expensive resistors cannot handle the voltage and cause all sorts of trouble. An lsk389 is going to be better than 2 x 2sk170 from an electrical drift standpoint. Not going to make any difference in the sound. Now the pot makes a big difference. RK50 and P&G are definitely the best of the bunch, rk27 and tkd less so. Mainly in channel to channel matching. dact will do better on matching. digital attenuators are even better.

white delrin. turns out there is a .002 taper in the insides of the neutrik jack. will make a couple out of Teflon anyway

final production stax male jacks http://gilmore.chem.northwestern.edu/staxmale5.jpg in case someone wants to have the Chinese make up a batch cheaper than I can http://gilmore.chem.northwestern.edu/staxplug.pdf

from the left Arizona desert ironwood lignum vitae from craig in the UK new piece of lignum vitae Tasmania blackwood ebony red mallee redheart cocobolo jersulaem olive wood orange pekote

more wood aging over the ventilator at work http://gilmore.chem.northwestern.edu/dsc_0780.jpg steve would be proud

we aim to please!

I have not measured in a while, but the zeners keep it pretty close to 580 +/-5% 600V bias won't hurt the headphones, once in a while you might hear whooshing noises. Also depends on humidity.

using an amplifier that can do 100 volts peak to peak on high efficiency headphones that at most need 2 volts peak to peak is a fair bit of overkill. Its not that you can't do it, but any accident can fry the headphones or blow out your ears.

yep. and I never use pots >25k even if there is no external low pass filter, jfet and tube inputs have a specific capacitance which will form a low pass filter anyway for my system I could use 50 ohms if I wanted to.

the stax mafia believes in continuous improvement I wasn't even going to do this, then it happened anyway. Very minor parts placement issues. silkscreen error fixed http://gilmore.chem.northwestern.edu/boards/kgbhultraminipsV2.zip

our current mini board is for rk27 and tkd pots. if you think about it, the shorter the resitive path, the more mismatching you are going to have. So a bigger pot should always be better.

i'm using 10k quad rk27 for testing the preamp. its ok. if you can find the noble, those are better. minimum order from alpha is 50 pieces i believe

The khozmo is a massive piece of crap. I have 2 on my desk that after repeated tries, cannot be made reliable. wiper made out of material without enough spring and eventually it goes intermittent and noisy. The dact is also a piece of crud. At least it stays reliable for a significant period of time. The rk50, penny&giles, and constant impedance digital attenuators are the only things that work correctly forever.

this will be the power supply people should use for the kgst and kgdt heavy modifications by 3 people from the original kgbh power supply. http://gilmore.chem.northwestern.edu/kgbhultramini.jpg 5.3 x 4.37 inches original was 6.6 x 5.5 inches

it used to be that Disney would sue anyone with anything with the word "tron" in it.

npn transistors are always used in the same way as triodes dual gate mosfets (there are very few left) are used in the same way as tetrodes

more like KGSSSic

the cathode winding of opposite polarity is what mcintosh calls cross coupled cathodes. A patent from the late 1950's. Definitely made a big difference in distortion. And they did bifilar winding too. but otherwise standard steel with alternating E and I pieces. There was a very recent youtube that showed them making transformers for the reissue mc275.

that is close to right, because of the way supersymmetry works. i will when i have time get you the exact values. using this amp with 300 ohm headphones is probably pretty goofy, as the voltage swing will easily fry both the headphones and your ears. put mainly your ears. really designed for low impedance low efficiency phones. he6, that kind of thing. new supersymmetry dynalo is much better for high efficiency high impedance headphones

same as any of the .1uf ceramic caps, 15v or more

you are going to need a bunch of heatsink. use the off board power supply version.

NO. you are missing the point. The point is a fair bit MORE current. one 10m90s is not going to handle that. you would need 3. and you need 3 x fqpf8n80c. other than that, both supplies are about the same in cost and performance ksc5026 works fine as 2sc3675 or 2sc3840 replacement and is a current part ksa1156 works fine as 2sa1486 replacement with the 270V zener and is a current part

depends on if you are pabbi1 or not.

coming soon to a file server near you http://gilmore.chem.northwestern.edu/kgdt.jpg 4.15 x 4.17 inch think of it as a cheap swiss army knife of electrostatic amplifiers works with any standard dual triode suitable for voltage 1 per channel Russian 6n1P, 6cg7,6fq7,ecc99,12bh7.... NOT designed by morons with just a digital voltmeter NOT open loop Not high distortion rationally priced (you get where I'm going here)

free gerber viewer for board files, open zip folder http://bayareacircuits.com/free-gerber-viewer/