Author Topic: Kaleidiscope  (Read 131 times)

Aleph Null

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Kaleidiscope
« on: July 21, 2021, 11:06:48 AM »
This is a basically stock Pedal PCB Minnow, I reduced R13 from 100k to 91k which reduces the minimum resonance a little. I found this to be useful in the sample/hold mode.



This circuit was quite noisy at first, but only in bypass. I shielded the input and output cables and this helped a little. Eventually, I traced the noise to IC2, the LFO opamp. It was screaming like Satan's own 56k modem and the output jack was picking it up. I replaced the TL072 with a JRC 2068D. The scream became a loud hiss. I covered the opamp and socket with masking tape, then shielded that with HVAC tape, which is grounded to the enclosure. That got rid of the noise.



This is a fun circuit, but definitely plan on having to debug it to get it sounding right.

jimilee

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Re: Kaleidiscope
« Reply #1 on: July 21, 2021, 01:36:08 PM »
Very nice.  Brian had one a few years back, I really dig it. I like the 125b foot print too.


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Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

harryklippton

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Re: Kaleidiscope
« Reply #2 on: July 21, 2021, 08:30:24 PM »
Awesome graphic! That looks killer