Hello,
The problem with moving the power, is that I finished my main synth
cabinet, and this is all in a 2nd cabinet. It's only the divider,
percussion, and gated comp in a little rack mount case. It has a
power cable that goes into my main cabinet where the supply is
located. I've tried changing the way I have those few modules wired
together, but it hasn't helped. I will try larger caps and adding
resistors, but I already have the ferrite beads in place. The supply
is 3 amps. I was running on 1.5 amps with only a few less modules.
I guess if the added power line filtering doesn't work, I can move the
modules around. Swap a module from my main cabinet w/ the gated comp.
(tho I hate to do it, because it works out perfectly having all the
percussion controls in that 2nd external cabinet)
I played it for a few friends over the weekend and they didn't even
notice the noise in the background. They were just shocked with the
awesomeness of the percussion coming out of it :)
One last question. I need to double check it, but I might have used a
few polyester caps instead of ceramic caps as bypass caps on the IC's
in the cynare (I ran out of ceramic). Is this the sort of problem
that could cause? If so, would it have been better to substitute 100n
for 10n ceramic rather than poly for ceramic?
Thanks a lot!
The problem with moving the power, is that I finished my main synth
cabinet, and this is all in a 2nd cabinet. It's only the divider,
percussion, and gated comp in a little rack mount case. It has a
power cable that goes into my main cabinet where the supply is
located. I've tried changing the way I have those few modules wired
together, but it hasn't helped. I will try larger caps and adding
resistors, but I already have the ferrite beads in place. The supply
is 3 amps. I was running on 1.5 amps with only a few less modules.
I guess if the added power line filtering doesn't work, I can move the
modules around. Swap a module from my main cabinet w/ the gated comp.
(tho I hate to do it, because it works out perfectly having all the
percussion controls in that 2nd external cabinet)
I played it for a few friends over the weekend and they didn't even
notice the noise in the background. They were just shocked with the
awesomeness of the percussion coming out of it :)
One last question. I need to double check it, but I might have used a
few polyester caps instead of ceramic caps as bypass caps on the IC's
in the cynare (I ran out of ceramic). Is this the sort of problem
that could cause? If so, would it have been better to substitute 100n
for 10n ceramic rather than poly for ceramic?
Thanks a lot!
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Possible solutions.
>
> -Run the power wires from each module to a common point near the PSU.
> -Increase the input decoupling capacitors on the boards to 47uF.
> -Place 10 ohm resistors in series with the +/- power rails to the
two modules.
> -Use two power supplies. Chances are that the one is being
overstretched a
> little.
>
> Ken
>
> >Hello,
> >I've been playing around with the gated comp and percussion modules I
> >built, and noticed that I hear whatever I put into the gated comp
> >input at the cynare filters output. It's especially noticeable w/ a
> >noise source. I'm sure it isn't picking up its own noise generator.
> >I'm also sure that it is going through the power lines, as I can hear
> >it even if nothing else is patched.
> >I tried grounding the gated comp's input individually, with a shielded
> >cable, and it didn't help.
> >
> >Does anyone have any ideas of what else I could do?
> >
> >thanks
> >
> >
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
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>