Home Amp/Preamp Asylum

Looking for a new Amp or Preamp? If you're after tubes, post over here.

Re: Yamaha C-2 missing Bass

Thanks for the help. Its great to get feedback from someone who has the same matching pair (C-2 and B-2). Without manuals, schematics or familiartity with the equipment, I have been flying blind.

I cleaned contacts and pots in both the preamp and power amp and all of the problems have disappeared. The sound quality I am getting amazes me and I feel pretty lucky to have found them. Why aren't these more widely known? Or are they?

I measured the drop in the bass by using a CD with pink noise in 1/3 octave bands, measuring the voltage at the tape-outs and at the second pre-outs with a multimeter, setting the volume control so that the the two voltages matched at 1000hz and then checking how they were at other frequencies. The tape-out voltage was pretty flat across the spectrum but there was a big bass droop at the pre-outs (a bit different in each channel) which matched what I was hearing. After cleaning, the problem vanished. I think that both the B-2 and C-2 had been sitting unused for a long time and surface oxidation was a problem in contacts for both channels.

Thanks for the tip on setting the B-2 for DC coupling. I wasn't sure about this.

Regards

David


This post is made possible by the generous support of people like you and our sponsors:
  Signature Sound   [ Signature Sound Lounge ]


Follow Ups Full Thread
Follow Ups


You can not post to an archived thread.