kevin gilmore

the update on the board was for the mpsw06 transistors because the 2sc1815 are hard to get now. otherwise no difference

I don't think the JT has a constant output impedance. But I will analyze to make sure. My attenuator has both a constant input impedance and a constant output impedance. need to break the delete key on birgir's keyboard!

lsk170 and 2sk170 have the gate in the middle, not the either end like the dual.

notice that 2sk170 or lsk170 are not pin for pin, you have to bend the pins to get the correct pinout

measuring that is very tough. Need a screen room, a very heavily filtered mains supply and expensive meters designed for this kind of thing. Mine is a keithley ac microvolt meter. And you have to block the DC first. Film caps work for this.

is lsk489 any easier to source? a pair of lsk170's or 2sk170's also works

there is no 60hz unless there is excess current being drawn by the headphones the 500V version of the kgsshv takes the voltage directly from the main unregulated supply, so no chance of hum even with the headphone drawing much more current than it should.

so the bias supply is a voltage multiplier directly off the ac line, and its really high impedance. So anything that might load it even a little bit is going to cause 60 hz hum. if the diaphram slams hard against the stator, its going to discharge the bias a bit.

the T2 is the champion when it comes to listening way too loud.

input stage runs at 4ma, so yes it will work the original part was higher capacitance and krell used a 10k pot because of it. 10k part is still a better idea

will it fit, definitely, will it work, probably. since its a follower, i doubt there will be even the slightest change in sound. The amp is already very quiet, so might not make much of a difference.

the JT attenuator is not constant impedance. There was absolutely no reason why it could not have been constant impedance. Other than that I think it should work if it does not overload the transformer.

the mje parts I use are fully isolated, so I just use thermal pad, stainless steel screws, stainless steel washers. if you have the non-isolated parts, then you have to use the special plastic rings

ksa5 boxed up, 2 hours running, 109F at the top of the box.

do it right and put in the extra hole for the pot mounting. .393 inch from the center line of the shaft, .125 drill

I think this is it http://gilmore.chem.northwestern.edu/kgstpower.pdf got to start putting a date on the names of all of this.

if its the group buy here is the pdf of the board layout http://gilmore.chem.northwestern.edu/kgst-miniv03.pdf at least on my printer, it prints exactly the correct size. if you want to measure instead, I can give you the hole distances from any corner.

I think that more people knew how to fix this. but it would be so much easier to ohm out the other end of the cable.

I think that the 5 wires coming out of one side, knowing that one of them has to be safety ground should give you a real big hint as to how to fix them. But dumping in the garbage where they belong and getting a decent set of headphones is an infinitely better idea.

all of mikhail's monster cases (es2,ss1,sds xlr etc) have real problems. and of course the rest of his chassis are trouble too. #4-40 holes tapped to shallow in the .25 inch thick sides, causing the screws to crack etc... plus the rusting screws... most of the time i put into the ss1 was on a mill and lathe using carbide bits to remove and fix the holes. not to pick on someone, but this http://www.head-fi.org/t/739437/fs-audio-technica-l3000s-singlepower-sds-xlr#post_10983524 i mean you gotta be kidding. I would not buy that amp if it was $500. maybe $250 with shipping. Just to put the guy out of his misery. (i know someone else that has one of these and wants to dump it) but really what can you do to the thing. In balanced mode its really only useful for very high impedance headphones, there is no phase splitter etc. A 60+ lb boat anchor.

I have a singlepower quad step attenuator. Even more valuable than a pair of dual's And every bit as equally fucked. The solder job is typical Mikhail.

there will be a kgsshv version of joamats power supply layout. my original T2 power supply had about 1.5 mv of noise, the kgsshv power supply is about 3 microvolts of noise.

updated the board layout for c1815/mpsw06 http://gilmore.chem.northwestern.edu/boards/megatron.zip

label fixed

the pin spacing is right and you put the stn9360 vertical. first you straighten the pins. Same as the new T2 boards. works fine.