The amp build is over in this thread. So far, having issues with too much Ids and need to adjust source resistors on bottom half.
http://www.diyaudio.com/forums/pass-labs/146310-bf862-preamp-45.html#post4919251
http://www.diyaudio.com/forums/pass-labs/146310-bf862-preamp-45.html#post4919251
The amp build is over in this thread. So far, having issues with too much Ids and need to adjust source resistors on bottom half.
http://www.diyaudio.com/forums/pass-labs/146310-bf862-preamp-45.html#post4919251
Works now. Had a bad wire - sounds pretty good. Need to build second channel now for a real listening test.
Yes, sort of, I matched them in-situ. After they were installed in circuit, i measured current across each one and they were within 5% (all JFETs from same reel). The outliers, I would remove and pop a new one in until the currents matched. Typically, there was 1 out of 4 that needed to be replaced.
In stereo now. Sounds great.
In stereo now. Sounds great.
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In the previous picture of your board didn't you use one of the newer solid polimer caps ?
Is there any reason you changed to other capacitors ? And any reason why you decided
a 5% match was close enough for the jfets ?
Is there any reason you changed to other capacitors ? And any reason why you decided
a 5% match was close enough for the jfets ?
That amp has moved to this thread:
http://www.diyaudio.com/forums/head...f862-based-se-class-headamp-without-heat.html
I changed it to use larger value for deeper bass with lower impedance loads. 47R is for 250ohm headphones.
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