Author Topic: PT2399 Tape Stop Effect  (Read 235 times)

Aleph Null

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PT2399 Tape Stop Effect
« on: September 21, 2022, 02:43:12 PM »
I recall reading somewhere that it was possible to get a PT2399 delay to do a "tape stop" effect where the delayed signal slows to a stop. For the life of me, I can't find the forum post anymore. I think it involved grounding a pin through a resistor, but I don't remember which pin or recommended resistances. Has anyone else hear of this? Can you point me to a forum post somewhere?

harryklippton

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Re: PT2399 Tape Stop Effect
« Reply #1 on: September 21, 2022, 02:58:47 PM »
Whoa. I'd be interested in this too

madbean

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Re: PT2399 Tape Stop Effect
« Reply #2 on: September 21, 2022, 03:55:29 PM »
Yup. Use a 22R 1/4W resistor attached to pin1 of the PT2399. Put the other end to a momentary switch so that the switch grounds that resistor when pressed. When activated the resistor will drain current from the 5v regulator to ground. The result is the delay repeats will continuously drop pitch. After a few seconds the PT2399 will stop working but once you release the switch it will go back to normal operation.

I included this mod on the Loophole project many years ago. It's really fun to play with.

Aleph Null

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Re: PT2399 Tape Stop Effect
« Reply #3 on: September 21, 2022, 04:16:55 PM »
Yup. Use a 22R 1/4W resistor attached to pin1 of the PT2399. Put the other end to a momentary switch so that the switch grounds that resistor when pressed. When activated the resistor will drain current from the 5v regulator to ground. The result is the delay repeats will continuously drop pitch. After a few seconds the PT2399 will stop working but once you release the switch it will go back to normal operation.

I included this mod on the Loophole project many years ago. It's really fun to play with.

Thank you! I knew I had read about this somewhere. I'm working up a delay design and I wanted to experiment with this.

flanagan0718

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Re: PT2399 Tape Stop Effect
« Reply #4 on: September 21, 2022, 08:38:07 PM »
Huh. Thatís a neat trick!


Sent from my iPhone using Tapatalk

jessenator

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Re: PT2399 Tape Stop Effect
« Reply #5 on: September 26, 2022, 10:46:34 AM »
The result is the delay repeats will continuously drop pitch. After a few seconds the PT2399 will stop working but once you release the switch it will go back to normal operation.

Is there a way to control the drain time, by chance? Different resistor value?

Thanks.

Aleph Null

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Re: PT2399 Tape Stop Effect
« Reply #6 on: September 26, 2022, 03:06:20 PM »
The result is the delay repeats will continuously drop pitch. After a few seconds the PT2399 will stop working but once you release the switch it will go back to normal operation.

Is there a way to control the drain time, by chance? Different resistor value?

Thanks.

I haven't had a chance to experiment with this yet, so I don't know for sure, but a smaller resistor value should result in a faster drain time. Since the supply voltage effects the clock speed, there may be a minimum drain time/resistor value that's necessary to keep from locking the clock up.

jessenator

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Re: PT2399 Tape Stop Effect
« Reply #7 on: September 26, 2022, 04:42:38 PM »
I haven't had a chance to experiment with this yet, so I don't know for sure, but a smaller resistor value should result in a faster drain time. Since the supply voltage effects the clock speed, there may be a minimum drain time/resistor value that's necessary to keep from locking the clock up.

Ah, interesting. It'll be interesting to experiment with! Let us know what you find.