PT-80 too bright... Which cap changes will darken the tone?

Started by cdc3j, April 15, 2011, 03:08:26 AM

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cdc3j

The pedal works perfect and I'm probably going to add an expression for the repeats, however the repeats are too bright for my taste. I really like the sound of the Malekko Dark 600. I read that the .001uf coming from pin 13 of the 2399 will darken the initial repeat, and the .0022uf coming from pin 15 will darken each sequencial repeat. Is this correct? It looks like there's a 22k resistor in line before the .0022uf cap. Will that need to be altered as well? It's the middle of the night and I can't get to Radio Shack before tomorrow afternoon, so I'm wanting to know for sure before I go. Thanks so much...

Just ordered a byoc analog delay tonight so that'll be a project for next week. Been missing the bucket sound since I sold my Carbon Copy.

Thomeeque

Quote from: cdc3j on April 15, 2011, 03:08:26 AM
I read that the .001uf coming from pin 13 of the 2399 will darken the initial repeat, and the .0022uf coming from pin 15 will darken each sequential repeat. Is this correct?

Nope. Any "darkening" applied on the path starting at pin 10 of SA571 and ending at pins 6+7 of SA571 will darken first and each sequential repeat (incrementally = e.g. 3rd repeat will sound darker then 2nd).

Principally you have IMO three choices:

1. additionally darken 1st and each sequential repeat (incrementally)
2. left 1st repeat untouched and additionally darken 2nd and each sequential repeat (incrementally)
3. additionally darken 1st and each sequential repeat, but non-incrementally (3rd repeat will sound same as 2nd*)

Easiest and most common (and natural?) is first option. I would probably darken signal already at input of PT2399 (.0022uf coming from pin 15), so there is less quantization noise at the same clock frequency, or maybe at input and at output as well (e.g. .0022uf in 2N5088 based LPF). There's lot of options.

T.

* If we ignore darkening of the original circuit
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cdc3j

I found two of the places you were refering to, but need a little help with the others. I'm going to try to attatch the layout with the two circled. If someone could highlight the other options it would be great. Thanks