Hello,
I've done an active filter with cascaded 6dB cells separated by jfet buffer.
The buffer is done with 2 jfets in source follower configuration, one for signal, the second for ccs.
Before the first buffer, the signal is splitted, for the highs and for lows. There is 5 buffers cascaded, so I can rich 24dB/octave with four 6dB. I have a small dc drift after the 5 cells cascaded, something like 200mV (the jfets are matched).
The alimentation is a labo dc supply in + -15V, both channels are on the same alimentation.
The big problem is that I have a big big buzzzzzzzzzzzz on my stax (very good control...) But the buz is there only when I put some cable on the input... when the rca are free, almost no buzz.......
Any suggestions (before I go to battery operationn
)
Thanks
I've done an active filter with cascaded 6dB cells separated by jfet buffer.
The buffer is done with 2 jfets in source follower configuration, one for signal, the second for ccs.
Before the first buffer, the signal is splitted, for the highs and for lows. There is 5 buffers cascaded, so I can rich 24dB/octave with four 6dB. I have a small dc drift after the 5 cells cascaded, something like 200mV (the jfets are matched).
The alimentation is a labo dc supply in + -15V, both channels are on the same alimentation.
The big problem is that I have a big big buzzzzzzzzzzzz on my stax (very good control...) But the buz is there only when I put some cable on the input... when the rca are free, almost no buzz.......
Any suggestions (before I go to battery operationn
)Thanks
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