Simplistic NJFET RIAA

diyAudio Chief Moderator
Joined 2002
Paid Member
Hi Salas,
i have many 2SK170BL.
2X= 7.74mA idss
2X= 8.61mA idss
2X= 8.48mA idss
2X= 8.68mA idss
2X= 10.85mA idss
2X= 8.72mA idss

and i will buy soon other.
but it's possible to post a schematic?

Thank's Maxpou

They are enough. I just checked out the schematic that Merlin will make for using his double jfet chips with 10.5m average, and its OK for 8.5mA-8.7mA pairs in your stash if I changed some resistor values. So here it is for you, and I remind its brother reg not to search back. Please implement the regs with remote sensing, all of you. Its worthwhile.
 

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Member
Joined 2009
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Snowing all day, internet has gone till now, AC electricity going off, going on every half hour, all living in Europe:mad:

One channel LED's lit & voltage between GND & Q3 (BC550C) ok with 7.2V:)

The other channel LED's lit but voltage between GND & Q3 (BC550C) is 7.86V:confused:?

Can I use the NJFET RIAA or I have to wait until get 7-7.3V?
 
diyAudio Chief Moderator
Joined 2002
Paid Member
Yes but the two Jfet CCS for LEDs may be producing different currents or the LEDs behave differently at this current level. In the end, when everything works OK, I will guide you on how to match the output levels for both channels by using a test record and your DVM. That is what really matters. Is it playing music yet?