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JHS Pumpkin pie/patch mod schematic?

Posted: 28 Jun 2023, 19:19
by Lithium_Grim
Hi there,

I am looking into modding an opamp big muff with the Pumpkin patch mod by JHS. It adds a mids control and a 3 way gate switch.
The mids control is done, I guess, by altering the 1k2 in the tonestack to 500R and a 1k pot. The gate switch is a mystery to me. I presume it is done by switching between 3 values of fixed resistors. Does anyone know?

Re: JHS Pumpkin pie/patch mod schematic?

Posted: 29 Jun 2023, 00:23
by Echowreck
These are not my pictures. I do not own this pedal. Credit to @patrick_dixon on Twitter. Notice that R19 has been removed.

Re: JHS Pumpkin pie/patch mod schematic?

Posted: 30 Jun 2023, 06:31
by Lithium_Grim
Thank you! Here a gift back for those who are searching for a schematic with these mods. It is a 1978 version Opamp Muff with tone switch and added optimalisations as mentioned by Gottfried Divos.
Image

Re: JHS Pumpkin pie/patch mod schematic?

Posted: 01 Jul 2023, 03:13
by bumblebee
Lithium_Grim wrote: 30 Jun 2023, 06:31 Thank you! Here a gift back for those who are searching for a schematic with these mods. It is a 1978 version Opamp Muff with tone switch and added optimalisations as mentioned by Gottfried Divos.
Image
Gottfried (analogguru) was somewhat of a polarizing figure around here but I always enjoyed his humor and company.

8)

Re: JHS Pumpkin pie/patch mod schematic?

Posted: 01 Jul 2023, 08:22
by Lithium_Grim
True. I find it very important to credit people who did the work and not give people the impression that I was the OG. Credit where credit is due.

Re: JHS Pumpkin pie/patch mod schematic?

Posted: 04 Jul 2023, 01:00
by jalmonsalmon
I may have to make a PCB from this schemo.... Love that mod.
Hopefully this one works out... THANK YOU!