Thanks!

thanks, will try this

Thanks so much, this advice was very helpful. It does not completely solve the problem of resonance of the toms/congas (especially for the midconga) but attenuates it, so as to be able to record sound!
In this photo you can see how i've connected the swithces to ground:

bmaximus wrote:It does not completely solve the problem of resonance of the toms/congas (especially for the midconga) but attenuates it, so as to be able to record sound!

Are you using external or internal PSU?

I have an internal toroidal resin transformer. The problem is not so much the 50 Hz hum, but a constant sound floor of the same tonality of each instrument (toms / congas) predominant in the mid conga. This defect is very similar to what i've encountered by modding the decay of the snare drum in my korg monotribe following the instructions found on the web. I think it's something inherent the project, depending from the way the sound is generated.
Have you any idea why grounding the switches reduces the issue?

bmaximus wrote:I have an internal toroidal resin transformer. The problem is not so much the 50 Hz hum, but a constant sound floor of the same tonality of each instrument (toms / congas) predominant in the mid conga. This defect is very similar to what i've encountered by modding the decay of the snare drum in my korg monotribe following the instructions found on the web. I think it's something inherent the project, depending from the way the sound is generated.
Have you any idea why grounding the switches reduces the issue?

big pieces of ungrounded metal function as antennas.. thats all i know. this part of the circuit is very fragile when it comes to interference.

The monotribe thing sounds familiar, I undid all the mods I tried on monotribe because of it.

I have the impression an internal psu makes the issue worse, but I'm unable to test (still have to find an external psu to do that)
I had my friend check his 2 808's and he confirmed the problem is also there, but definitely not as bad.
I wonder what else can be done..

rv0 wrote: big pieces of ungrounded metal function as antennas.. thats all i know. this part of the circuit is very fragile when it comes to interference.

The monotribe thing sounds familiar, I undid all the mods I tried on monotribe because of it.

I have the impression an internal psu makes the issue worse, but I'm unable to test (still have to find an external psu to do that)
I had my friend check his 2 808's and he confirmed the problem is also there, but definitely not as bad.
I wonder what else can be done..

I have the external transformer, but unfortunately i've removed the socket from PCB, so I can't try if the noise is at same level. Today i've realized that a lot depends on the input signal gain. Connecting the master output of the Yocto to the Focusrite Scarlett 2ì4 the issue in question is quite audible, while connecting the individual outputs to the mixer Yamaha MG10XU you can obtain, taking the low gain, a sound more than acceptable! Judges by your ears from this recording and tell me what you think. If i increase the gain comes out a too high noisefloor: hum, click from the sequencer...

https://soundcloud.com/maxibi/yocto-sou ... tomscongas

Yeah I also noticed the output of the yocto is quite "hot".. at normal level the noise is less obvious.

maybe use plastic slide switch if there is some