Grounding?

[fadedpaper]

Sorry to be completely ignorant here, but my midibox sid puts off nothing but noise. I've built it with the Optimized PSU, exactly as the schematic shows (as far as I can tell). The thing that puzzles me most is that even when the power is switched off, I get tons of noise coming out of it. When I switch it on, the noise just doubles. I've noticed that when I touch certain parts of it with my finger the buzzing gets a lot quieter. Is this a grounding problem? What could fix it?

Also, the noise I get out of it when it's switched on sounds like digital static. I get the faint startup sound (behind a wall of noise) and then comes the digital static. After the startup sound, the sid is not responsive, but all my debugging leads me to believe that it should be working. I cannot for the life of me figure out what's wrong with it. ??? Any suggestions?

[fadedpaper]

Thought this picture might help shed some light. Keep in mind I have no idea what I'm doing. Oh, and the case is made of plastic, it's kinda hard to tell from the photo.

mbsid shot1.JPG

[rutgerv]

Hi,

I'm not sure if I can help, because it's hard to understand your exact configuration, but I'll give it a try.

Some ideas:

- Check and double check the wiring of the PSU. Is there a chance you have swapped a supply wire with a ground wire?

- Check for any broken contacts in the audio path (from SID audio out to you jack socket). If there's a bad contact between the SID and your audio output you would end up having a 'loose wire' which can acts as an antenna for noise. It's similar to the noise that you get when you pull the cable out of a guitar and leave the amp on.

Let me know if this helps.

Greetings,

Rutger

[t_xen]

I can just barely see C1 and C2 on the SID board. Make sure the legs of those capacitors aren't touching each other or anything else.

[t_xen]

Btw, if they are touching, you could try mounting them like this....

hope this helps

(ugh, I noticed the solderball on the board in that pic.)

[julienvoirin]

check the ribbon between core and sid pcb :  V3 and V2 (both core/sid) differs on pinning for J10 !

did you try sidtestone app ? what's with it ?

cheers

[jdelgoulet]

I'm also using CORE V2 and SID V3 ... it does not work (no sound at all).

Here is a question for julien : J10 are not different ? are they ?

[fadedpaper]

Well, I gave up on my optimized PSU and went back to the standard one. It's working again. Slightly buzzy, but better than not working at all. Thanks for your help anyway guys.