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Carl Martin - Crush Zone [traced]
Posted: 05 Dec 2016, 15:16
by Manfred
I traced the Carl Martin Crush Zone distortion and measured the voltages at the transitors.
Re: Carl Martin Crush Zone Schematic
Posted: 05 Dec 2016, 18:03
by Intripped
i assume the original pedal is not true bypass, there's a DPDT switch fitted in it, but i see a 3PDT switch in your schematic.
so probably you've already modified it, that's ok, but what i don't like are the pulldown resistors: they are always on the signal, and this is not good; you should put the 2M2 res after the 3PDT switch, and the 100k res before it.
thanks for your work, rock on!
Re: Carl Martin Crush Zone Schematic
Posted: 05 Dec 2016, 18:23
by Manfred
Intripped wrote:i assume the original pedal is not true bypass, there's a DPDT switch fitted in it, but i see a 3PDT switch in your schematic.
so probably you've already modified it, that's ok, but what i don't like are the pulldown resistors: they are always on the signal, and this is not good; you should put the 2M2 res after the 3PDT switch, and the 100k res before it.
thanks for your work, rock on!
Thank you for pointing that out, no I didn't modify the circuit, that was my mistake.
Here the corrected schematic:
Re: Carl Martin Crush Zone Schematic
Posted: 06 Dec 2016, 06:55
by Manfred
I found a modded schematic in my schematic library, and add the mods to my schematic.
I have no idea how the mod affects the sound.
Who knows more about?
I am not sure whether the 39k and 1uF values are right, because the original schematic is small sized and blurred.
Re: Carl Martin Crush Zone Schematic
Posted: 07 Dec 2016, 14:11
by EddieTavares
The input cap is 220p, is it correct?
Re: Carl Martin Crush Zone Schematic
Posted: 07 Dec 2016, 16:20
by Manfred
EddieTavares wrote:The input cap is 220p, is it correct?
Yes, it is correct.
The added image shows the input capacitor C10,
you can find the imprint "221".
- C10.jpg (37.53 KiB) Viewed 2166 times