buzz problem please help...

[hugobors]

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

[hugobors]

OK.... I went to battery operation....... nothing change, same buzzzzzzzzz.......
My source is for testing a discman with battery....... so the only thing on AC line is the stax...
Nothing is connected on ground, is this the problem?????????

[MikeBettinger]

Hi,

You might try posting a basic drawing of what you're describing. It's a bit unclear. What input are you talking about (connecting- buzz, no connection- no buzz) and I'm assuming the Stax is a headphone amplifier??

Regards, Mike.