Delay mod ideas, help.

[nelson]

I have a Princeton delay chip. already built a Rebote 2 delay a while ago.
I want to make a delay with this chip and I want it to be more versatile than the rebote 2.
I dont want miraculous higher fidelity on longer delay times.
I want a seperate out for just the delayed signal so I can effect just the delay in a stereo set up. Maybe a way to pan the delay left and right at a certain rate. I would also like to be able to perform the same function as the "hold" function on the DD-3 as in flip a switch and the delay just repeats what was last sampled, without sampling further guitar.

Can anyone point me to relevant schematics?

Suggest possible mods working from the delays already based on this chip(GGG)(GEOFEX)(TONEPAD)?

thanks guys!Nelson

[geertjacobs]

Try the PT-80.
Complete project description available at http://www.generalguitargadgets.com.

In this thread is a mod suggestion for a stereo out.
Try the archive for a lot more info on the PT-80.

[nelson]

Thanks for the link.

I sort of know how to get just the delayed signal in say the left channel and the dry signal out of the right. However how can I get the delay to pan left and right? for example one repeat left, one repeat right ad nauseum. Or pan left to right. Plus I have no idea how to make the pedal just sample and repeat without resampling whats being played. Perhaps a momentary switch to lift the input to the PT2399, with the mod for really long feedback? but then surely the chip would just sample the "silence"?

[bioroids]

I dont think theres a way for doing the Hold function on the PT2399. If you go by the aproach of infinite feedback every repeat will get filtered and will not sound the same. You need a way to make the chip stop sampling and erasing what is on its memory, and just playing it back forever, and the PT2399 doesnt provide any means to control that... that sucks

Luck

Miguel

[nelson]

I thought I might be trying to make a diamond from a lump of coal.

Thanks Boiroids.

[moosapotamus]

You need a way to make the chip stop sampling and erasing what is on its memory, and just playing it back forever, and the PT2399 doesnt provide any means to control that...

What if you broke the junction of point A and the 1uF cap that goes into the 571 (pin 11), and stuck in a SPST stompswitch (latching, momentary, whatever...)? When you open that switch, wouldn't the delay line act the same as if you were to just stop playing? In other words, the repeats would continue, but there would be no additional input into the delay line. But, the realtime signal path would still be active. So, you could continue playing on top of the older repeats. Wouldn't that work?

Also, if you wanted the repeats to go to maximum (or just some other setting) when you stepped on that switch, you could use a DPDT switch with one half of the switch breaking the input to the 571, and the other half switching in a resistor (or a second pot or trimpot) to drive the repeats to max.

~ Charlie

[bioroids]

Yes that would work, but the "repeated" signal would go out of the chip and in again, being filtered, ad/da converted on each cicle. This is different to a "real" hold, in wich the sound is sampled once and played over and over again (without leaving and entering the chip).

You can do what you say of course, but after ten repeats (more or less) the sound would be heavily filtered and destroyed (can be cool anyway). You can add loop outputs at this point to connect other effects on the feedback path and further destroy the repeated sound 

Luck

Miguel

[nelson]

You need a way to make the chip stop sampling and erasing what is on its memory, and just playing it back forever, and the PT2399 doesnt provide any means to control that...

What if you broke the junction of point A and the 1uF cap that goes into the 571 (pin 11), and stuck in a SPST stompswitch (latching, momentary, whatever...)? When you open that switch, wouldn't the delay line act the same as if you were to just stop playing? In other words, the repeats would continue, but there would be no additional input into the delay line. But, the realtime signal path would still be active. So, you could continue playing on top of the older repeats. Wouldn't that work?

Also, if you wanted the repeats to go to maximum (or just some other setting) when you stepped on that switch, you could use a DPDT switch with one half of the switch breaking the input to the 571, and the other half switching in a resistor (or a second pot or trimpot) to drive the repeats to max.

~ Charlie

hmmmm, I dont need fidelity....

Thanks Charlie

Now, what about a panning circuit?

[moosapotamus]

Commonsound Stereo Panneur
http://commonsound.org/kits/doku.php?id=panneur

~ Charlie

[nelson]

Surely there is something simpler...........

I have googled and can only find something just as complex.

[bioroids]

If the panning has to be in time with the repeats it will not be too simple.
Check out GEOFEX theres an article called VCA Aplications that has a simple panner inside.

Luck

Miguel

[Processaurus]

If you're looking for a traditional ping pong delay like in commercial pedals I think you would need two delay lines, one for each channel.  The second delay is fed from the output of the first.  I'm guessing the regeneration would go from the output of the second one through a buffer and a volume control back to the input of the first line.  You could even have different delay times on each one.

I actually like the idea of a tremolo type panner on the delayed signal better, its more unique (the DD5 does ping pong and the hold thing I think, and both line 6 delays definately do the ping pong thing)  and also you don't need two delay circuits.

The most bang for your buck mod might be having an external effects loop in the regeneration path, it sounds super cool with lots of things (EQs (you can do a great parody of tape delay), harmonizers, octave distortions, vibrato, reverb (could sound like the roland space echo's spring reverb), a booster(to change the feedback amount) etc.), pretty much anything you can get you're hands on.  The only commercial pedal I've seen with that is the Moog delay.  Looking at the tonepad rebote 2.5 delay, I would try inserting the loop between the repeats pot and the 1uF cap before it.

OOoo, just had the thought that you could figure a way to do the ping pong delay thing with your old rebote delay in the FX loop, if, hypothetically speaking, you were to build the fx loop mod into your new delay.