Noisy SD

When I turn up the SD volume, low-level non-steady noise is added to the signal. The SD and its controls works fine, and all the other instruments are quiet (no noise is added when I turn them up). Does anyone have an idea about a good starting point to look for a solution?

Thanks!

Internal PSU? I just put mine and it adds a lot of noise on the toms...

gihaume wrote:Internal PSU? I just put mine and it adds a lot of noise on the toms...

Yes it could be the problem, take away the transformer and listen what's happend

gihaume,

I had noise at the Tom/Congas too after I added the internal PSU in my metal case. I started poking around a bit and I have now put the ground of the power supply board to the chassis. Noises gone!!

jeroenbvo wrote:I have now put the ground of the power supply board to the chassis.

OMG thanks! I have to scratch the paint of the enclosure to ground it

I'm not using an internal PSU, so that's not the problem. Glad to see the noise problem for the internal PSU is solved though!

As to my problem, after checking all the components I noticed that the resistor for R191 only had a measured value of 5KΩ instead of the 10KΩ of its color code. I'm going to change this one out and see what happens before I try anything else.

So all the components appear to be in the right place, but after doing some recording with my Yocto, I noticed that the weird nose is always present in the signal, and gets louder as I turn up the SD volume. It's not a constant noise, but very erratic, almost like the crackling of a dirty vinyl. I'm guessing there's a ground problem somewhere, but I wanted to check if anyone has some ideas before I start debugging again.

DC to the pot?

As I bought a replacement C945 for Q49, I desoldered the transistor that was in place, and tested the Yocto without Q49 - no change at all. The snare drum played fine, but the noise was still there. I also measured the pots for DC while in operation, nothing there either.

Anyone else have any idea? And does anyone else have the same crackling noise on their output?

Detail : I only have noise on the master out and the snare out. The other individual outs are quiet. The noise is always there on the master out and turning up the snare volume increases the volume of the noise.

I am not sure if your noise issue is similar to the one I had (topic "Snare snappy not working").
A constant noise on the snare might be due to an offset in the envelope.
In my case, the envelope was not completely closing for some time.
I added a 1 Mohm resistor in parallel to C52 to solve the issue.