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Author Topic: Digitech DSP128 Reclock'd  (Read 1776 times)

lostchocolatelab

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Digitech DSP128 Reclock'd
« on: July 07, 2016, 06:51:55 PM »

Accidentally happened on your site awhile back and fell head-over-heels with the idea of reclocking old processors to squeeze new noises and textures out of them. Not neccessarily an electonics wiz myself, your tutorials provided a healthy dose of optimism and after nabbing a couple of 1799's from you I set off w/ a noise minded friend to modify one of my fave mutli-effect units, the Digitech DSP128.



Things were off to a great start as we grabbed some +5volt to power the 1799 and the proceeded to remove one of the crystal oscillators and feed the output of the 1799 back into the circuit.
Unfortunately, we selected the wrong clock to swap out and ended up modifying the update speed of the LED display.  ;D

https://vine.co/v/iYDiE0XXOrd
https://vine.co/v/iYjhItht3Kz

Uhh, ok...let's try this again shall we...this time with another clock:


The intention was the switch the original clock in/out as suggested in one of your 1799 tutorials but we were never able to get the original (or replacement) to work again.
However, the 1799 WORKED and enabled variable control of the clock speed!

I ended up deciding on a few different controls on the front panel for the manipulation of the clock:

1 X 10k Pot for Course Tuning


1 X 1k Pot for Fine Tuning
1 X SPST Switch shorting across the pins of the 10k Pot
1 X SPST Switch shorting across the pins of the 1799 Frequency Jumper



Not a whole lot of room left on the front panel for additional mods, but love seeing your "break out rack" of switches for further hacking.

Any suggestions on where to dig next to wrestle additional functionality out of these type of beasts?

Would be interested in any suggestions on where to poke in order to enable sample/ hold functionality or buffer looping.

Thanks for providing a great resource for circuit bending in addition to parts that facilitated this bend.
Will holler back with some sound samples soon.

Cheers,
lcl
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Circuitbenders

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Re: Digitech DSP128 Reclock'd
« Reply #1 on: July 08, 2016, 02:01:24 PM »

Nice job!.

Try finding the RAM chips, and taking a look at their datasheet. Several of the pins will be labelled with 'A' plus a number, and probably either 'D' or I/O'. If you short these pins together you can probably glitch any effect that uses the RAM, such as the delay, pitch shifting, reverb etc. You might get looping if you also use the pin labelled WE (write enable).
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i am not paid to listen to this drivel, you are a terminal fool

Thanenut

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Re: Digitech DSP128 Reclock'd
« Reply #2 on: January 09, 2018, 09:40:21 AM »

Wow, it's great. It's really awesome. I want to do you very much.
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Rieger

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Re: Digitech DSP128 Reclock'd
« Reply #3 on: January 16, 2018, 01:41:12 PM »

I love your setup, Lostchocolatelab. Shame you never followed through with the sound samples. I would love to hear some.
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lostchocolatelab

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Re: Digitech DSP128 Reclock'd
« Reply #4 on: August 14, 2018, 05:02:18 AM »

Sadly, this mod didn't hold for long. It created a cool pitch-bending effect when the knob was turned, but didn't modulate or stretch much as-is. Further explorations with the pins suggested didn't bear any good fruits and then the 1799 stopped working. I dropped another in and it worked awhile longer...but went dead as well. (I'm not super-electric minded...so not sure where the fail is...but that is the danger/ excitement, right?)

Things went much better on a couple of Ibanez DM1100's where I externalized the clock-speed trim and wired a stereo pair of them up to a couple of expression pedals.

The madness ensues on track 5 off my forthcoming album Lost Landscapes:
https://youtu.be/w17iXp2fCgU

The rest of the album comes out at the end of the month:
https://lostchocolatelab.bandcamp.com/album/lost-landscapes

Some serious guitar noise and pedalboard effect trickery on this!

More bending and circuit pics here:
https://www.instagram.com/lostchocolatelab/

Keep making tha noize!
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TexasHouston

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Re: Digitech DSP128 Reclock'd
« Reply #5 on: September 19, 2018, 10:24:48 AM »

ool pitch-bending effect when the knob was turned, but didn't modulate or stretch much as-is. Further explorations with the pins suggested didn't bear any good fruits and then the 1799 stopped working. I dropped another in and it worked awhile longer...but went dead as well. (I'm not super-electric minded...so not sure where the fail is.
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