Collosalous Help!

[dfine22]

I built the board according to the layout but haven't boxed it up yet and then noticed that Brian has a update regarding  a diode change to 1n5817 and 100uf for C26. He indicates that his helped with the clock noise on his prototype only.  Now I am confused.
Should I leave it stock or make the changes in the update.
Thanks, David

[gingataff]

I'm finishing off a collosalus now and have some clock noise, I wish I'd done the mod or at least put some sockets in.

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[dfine22]

thanks gingataff. No one else seems to be responding!

[alanp]

I changed the diodes in question and the capacitor.

I'm still getting clock noise.

Can you get bleedthrough on MN3007's at all?

[electricstorm]

If I read the build doc right, I think he also said you could dial out some of the noise with the biasing and could probably get less noise with a 12v supply.

[Scruffie]

Do you have clock noise? If not leave it stock, if so, try the mods.

I changed the diodes in question and the capacitor.

I'm still getting clock noise.

Can you get bleedthrough on MN3007's at all?

What do you mean by bleedthrough?

Did you use board mounted pots? Long wires crossing etc can be a source of clock noise and board mounted pots (or the DIY kind) can help to keep that down.

It may also have clock noise due to too higher delay time (clock timing cap is too higher value).

Are you using a switch mode power supply? I think that's the issue Brian had hence the changes.

[dfine22]

Stil having some clock and a bit of extraneous noise.  I was meticulous with the build also. Darn. I used several different power supplies as well (Voodoo labs pedal power, one spot. etc.)I guess I'll have to make the recommended cap and diode changes.

[Hangingmonkey]

Try 12v, that got rid of the noise for me. I cant remember if i did the diode and cap mods

[dfine22]

Thanks, I thought that was what the voltage converter was supposed to do?

[gingataff]

I tried mine with a 12v supply and the clock nose is gone.
It needs rebiasing though and I want to replace the fake 4558s I got from tayda with some real ones and see if that makes a difference.


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[Scruffie]

How odd it went after that... guess the regulator wasn't getting enough voltage at 9V.

The changes should let more voltage through so probably help.

What makes you say the 4558s are fake? They work right...?

[pk1802]

I had a similar problem. I was using a switching mode power supply(like the one-spot or powerall), and I was getting a ton of noise, even when the collosalus was the only thing using the power supply. I just used a old standard transformer style wall wart, and the noise came down by an order of magnitude. It still makes some noise, but not nearly as much. Hopefully this can help someone else who is using the search feature to find a solution to this problem.

[Scruffie]

I had a similar problem. I was using a switching mode power supply(like the one-spot or powerall), and I was getting a ton of noise, even when the collosalus was the only thing using the power supply. I just used a old standard transformer style wall wart, and the noise came down by an order of magnitude. It still makes some noise, but not nearly as much. Hopefully this can help someone else who is using the search feature to find a solution to this problem.

This is probably down to heterodyning, 3 things switching (Supply, LT1054 & Clock) and the different frequencies start to interact.

Probably can be cured but easier to just use something transformer based.