headphone outputs noise on Virus Indigo
 

Hello!

When I plug the headphones into the phones socket I hear a constant white noise (that is not so loud if the master knob is at maximum) but still very audible even then. If I use outputs 1-2 or the others the noise dissapears and it's all normal. I wonder if anyone has / had similar problems? Is this normal, i.e. the phones output is noisy?

UNSOLVED: Headphone output white noise
 

Sorry to wake up this OLD thread 11 years later. :-)

That's very interesting. I have the same problem on an Indigo I just picked up really cheap. The constant white noise is independent of the volume level. If I put my headphones into the main left out, the synth sounds perfect.

The headphone jack is mounted on a small daughter pc board. It is fed the main output signal from the main board and runs it through its own amplifier. Clearly the main output signal is just fine so the problem must like in the headphone amp board.

I'm going to ask Access service if a replacement board is available.

Had anybody else seen this?

Access replied and said that the hiss will be reduced if I use low-impedance headphones. I don't think they understand just how loud this hiss is. I explained that I have been using Philips 32 Ohm studio phones which are already low impedance. I also tried several other sets just for good measure. The results were the same... a hiss added to the signal that is MUCH louder than the background noise I've ever heard from any headphone amp. It's not a little normal background noise. It's a failure of some sort.

Hopefully they will respond to my additional input.

The headphone amp on the Indigo and surely the KB is just a simple fixed-gain amp. I would imagine the gain is between 3 and 6db. If they don't offer any solution I will just replace the electrolytic caps on that little board.