"FearlessFerret" wrote in message
...
I'm in the middle of a multi-year project to digitize my vinyl collection
and I've got a reucrring problem that's driving me up a wall.

I have a Dual CS 528 turntable hooked to a Pioneer SX-201 which is
functioning as preamp. My homebrew PC (a dual-CPU 1 GHz Intel server
board) sound card (a late-model low-end SoundBlaster) is wired to the tape
in/out jacks. A cassette deck is connected to the CD inputs.

Most of the time, the setup works fine. It's not audiophile quality by a
long stretch, but it works well enough that I hear the music and not the
technology.

The problem is that without warning, one or the other channel will drop
out partially or entirely, with a 60-cycle hum appearing noticeably (but
not at full volume). If I pull and reinsert the turntable inputs, it goes
back to normal, and pulling and reversing the turntable's power cord also
clears it.

Thinking that this looks like an intermittent ground loop, I took care to
plug the amp, TT and the PC into the same (battery backed-up circuit of
the) UPS. Didn't help.

One other thing I noticed is that sometimes the signal will drop out when
there is a spike on the line (like when the dehumidifier turns off) but I
can't say I've noticed that since I put everything on the UPS. I have
even replaced both the turntable and the amp and get the same problem.

Over the course of the summer the setup was not giving me much trouble,
but in the past couple of weeks I have difficulties several times a day.

Now I'm wondering if there is some kind of diode effect somewhere that is
causing a charge buildup, but at this point I'm just veering into wild
speculation because I'm all out of ideas.

/ff

Duals are notorious for output cables going bad. That's my guess.

Especially the white and black pairs.


Mark Z.