kevin gilmore

5pf is 3db down at 278Khz 3pf is 3db down at 500khz

10k input resistor, 55k feedback resistor should work fine. 4 volt peak to peak balanced input results in 22 volts peak to peak balanced output. 110k feedback resistor results in 44 volts peak to peak balanced output

this thing has a real problem. self powered bias. so you get to listen to music for maybe 30 minutes before the bias caps charge up, and before the headphones charge up. major stupid. anyone with a koss esp6 would know what i'm talking about. and yes eric65 is a fucking shill, but mainly an incompetent moron that cannot think and believes anything on the web. like the fact that the rkv has .01 ohm output impedance. see BHSE thread over there.

this is the cap you should use for the servo, fits the smaller holes 667-ECQ-E2105KF

yes I think that is the right part. too busy making these http://gilmore.chem.northwestern.edu/dsc_0783.jpg birgir had found another part that definitely works too

a lot of people were having trouble getting the original parts. you can still use the other parts in that board, just have to bend the transistors a bit.

for the servo cap you really want a film cap. which is why it is that big. ceramics as I have found out have real trouble as integration caps.

anything over 20v is fine for the servo

on that version of the board, the A970 and mpsw56 are labeled backwards. The correct position is the a970's on the left and the mpsw56 on the right. latest board had the silkscreen right, consult that for more info.

I think you have the mosfets and bipolars backwards. all the Motorola parts are current production. all of the ixys parts are current production

Do not jumper the 270V zeners! either install them, or leave the slots empty.

that is how I build mine.

the added zeners for the mosfets and changes in the labeling also the dual transistor option

http://gilmore.chem.northwestern.edu/kgsshvproductiondualmot.pdf you replace Q1,Q2,Q9,Q10 with ixtp05n100m I don't think lil-knight has the latest dual transistor layout. the Motorola transistors are a different pinout on the older boards. most of us like the bipolar transistors better.

nope, you need 2 high voltage windings

yes it looks real. I have not seen 2sc4686a parts as fake yet. I bought extra parts from many ebay vendors recently and all test ok. 2sa1968 are a different story, most are fake.

lots of 2sc4686a on ebay still for cheap. suggest you buy a bunch.

if you have the latest boards with the zener protection you can replace the 3rd stage bottom and top of the 4th stage with 05n100m (latest on board version) or solder the zeners on the back schematic was never updated I have never actually seen 2sc4686. only 2sc4686a which is a 1200v part

something with a pair of 35V windings would be ideal, 40V windings are going to probably overheat the power supply. And you may have to adjust the bias generator to lower the standing current.

the ref102 WILL NOT WORK it cannot operate in 2 wire mode you cannot use all enhancement mode mosfets it will go boom

you have to replace all 4 zeners. the second stage zeners need to be 33V and the first stage need 40V and the caps need to be voltage upgraded

probably any of the lsk389 would work, but never tried it.

yep 120 ohms or even lower

you change R7/R10 to 350 ohms which will give about +/-33V on the power supply.

default for 500v is the same 5ma. you change the emitter resistors at the bottom of the output stage. and you want a lsk389B. the lsk170B is available from diyaudio.com