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Title: What circuit is this?
Post by: mikepurcell on May 25, 2021, 03:09:45 PM

Anyone know what circuit this is? I got it on a haul of parts from a guy that was getting out of making pedals.

Transistors are:
2N2222
2N3904
2N5088
2x green LED's

2x spst
3x pots - haven't pulled them to check values yet.

Some kind of distortion or fuzz circuit, it sounds cool but it's got some problems. Plus I'd rather build my own.
(https://i.postimg.cc/4ns3982n/FDB0-F313-3207-49-A1-9-BB5-9-E7-B084-CC3-CF.jpg) (https://postimg.cc/4ns3982n)

Title: Re: What circuit is this?
Post by: Kevin Mitchell on May 25, 2021, 03:30:17 PM

Just throwing darts here, may be a NPN Tone Machine with whatever parts the dude had laying around.

Send a photo of the backside and we'll reverse engineer it.

Title: Re: What circuit is this?
Post by: mikepurcell on May 25, 2021, 07:17:08 PM

As requested.

(https://i.postimg.cc/Q9hXKV6z/937-C10-BA-82-BD-40-B7-9819-932-F8651451-E.jpg) (https://postimg.cc/Q9hXKV6z)

Additional info:
B5k - voltage sag pot
B25k - I'm guessing fuzz/distortion
A100k - Output pot

Looks like the switches are on each diode to take them in/out of the circuit. Diode 1 is connected to base of Q2, Diode 2 to base of Q3. Numbering them top to bottom from the top photo.

Title: Re: What circuit is this?
Post by: mikepurcell on May 26, 2021, 01:45:37 PM

Figured it out, it's a Dwarfcraft Shiva.

Title: Re: What circuit is this?
Post by: Fancy Lime on May 26, 2021, 05:30:15 PM

"... getting out of making pedals"? What is that? Never heard of it. Sounds serious. Please don't tell me it's contagious!

DIYstompboxes.com

DIY Stompboxes => Building your own stompbox => Topic started by: mikepurcell on May 25, 2021, 03:09:45 PM