# Momentary oscillation switch mod for Seabed delay (deep blue delay)



## Svenson007 (Oct 9, 2021)

Hey guys. I hope somebody can help me visualize the wiring for this. I know basically the input and output are wired to a momentary stomp (with some type of resistor in series to tame oscillation a bit) ….. when switched on they combine to create infinite feedback. I’m having a hard time visualizing where in the schematic these two points would come from. Is there a simple way to do this mod? This is for the seabed delay. I’m feeling rather dumb today and could use some help haha.

Could a wire come from one hole of R1 and R6 to the momentary switch? Then put the resistors in series with the wires going to the switch so they are still in the circuit. 

Like I said I’m sure it sounds rather dumb to most of you, please bare with me lol.


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## daeg (Oct 9, 2021)

Connect the green mesh and the blue mesh.



I've never built this circuit, but if it's capable of getting into oscillation with the 'Repeat' knob maxed out, this will do the trick. If not, we'll figure something else out.


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## daeg (Oct 9, 2021)

Do you have the PCB built?

You could test this using alligator clips. Connect Lug 3 of the Repeat pot with Lug 3 of the Level pot.


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## Svenson007 (Oct 9, 2021)

daeg said:


> Connect the green mesh and the blue mesh.
> View attachment 16853
> I've never built this circuit, but if it's capable of getting into oscillation with the 'Repeat' knob maxed out, this will do the trick. If not, we'll figure something else out.


Wow thanks man. I know the circuit is capable of reaching oscillation stock. Unfortunately I can’t visualize how I would physically connect these. I’ve been “painting my numbers” successfully for so long what seems obvious to all you guys unfortunately isn’t to me yet. I’ve done something similar on a vero project…… but for some reason it just clicked with me with vero…… all my mod experience is on vero. 


So would I connect say lug 2 of the pcb LEVEL 50k mounted pot to the anode positive lead of the capacitor c13, and R2? Physical jumper wire? Then same deal with the green? Then I would have a wire from each connection…. Blue and green going to the momentary switch? 

I really appreciate the help. I might be a hopeless student on this one, but you are getting me closer to understanding.


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## Svenson007 (Oct 9, 2021)

daeg said:


> Do you have the PCB built?
> 
> You could test this using alligator clips. Connect Lug 3 of the Repeat pot with Lug 3 of the Level pot.


Well I’m building it right now. Should be done the circuit in about an hour. I can test that. If that works. I guess I could just throw the momentary switch in between?


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## Svenson007 (Oct 9, 2021)

With this noise ensemble build from way back. It seemed obvious to me to connect row 2 and three to combine input and output to oscillate. Don’t know why this is different haha.


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## daeg (Oct 9, 2021)

Svenson007 said:


> Well I’m building it right now. Should be done the circuit in about an hour. I can test that. If that works. I guess I could just throw the momentary switch in between?


Exactly. You could use 1 alligator clip to connect the points together, or 2 alligator clips to connect them across a momentary switch. If you like the result, replace the alligator clips with wires.

I had this PedalPCB board mixed up with another EQD Delay. I actually do have this pedal on my board and use it quite frequently. The oscillation won't immediately onset. Depending on how the 'Delay' pot is set, it will take 1-5 seconds for the oscillation to reach unity volume, and after that it will gradually get louder and then too loud.

If you really want to make this momentary switch like a 'Hold' feature there are some other things we can do like add clipping diodes at the input of the delay to limit the level, bypass R19 for a quicker onset. But first, try out the mod suggested in the first reply and see what you think.


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## Svenson007 (Oct 9, 2021)

daeg said:


> Exactly. You could use 1 alligator clip to connect the points together, or 2 alligator clips to connect them across a momentary switch. If you like the result, replace the alligator clips with wires.
> 
> I had this PedalPCB board mixed up with another EQD Delay. I actually do have this pedal on my board and use it quite frequently. The oscillation won't immediately onset. Depending on how the 'Delay' pot is set, it will take 1-5 seconds for the oscillation to reach unity volume, and after that it will gradually get louder and then too loud.
> 
> If you really want to make this momentary switch like a 'Hold' feature there are some other things we can do like add clipping diodes at the input of the delay to limit the level, bypass R19 for a quicker onset. But first, try out the mod suggested in the first reply and see what you think.


Awesome! Thanks broski! I’m new here and honestly surprised of the quality help and specific info so fast! Something came up and I had to put the circuit down for the day about 3/4 through populating  I’ll throw it together later tonite or tomorrow night and let you know how things are going with some testing you suggested. Sounds like you can guide me to nailing down just what I’m looking for. Cheers buddy!


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## Svenson007 (Oct 16, 2021)

daeg said:


> Exactly. You could use 1 alligator clip to connect the points together, or 2 alligator clips to connect them across a momentary switch. If you like the result, replace the alligator clips with wires.
> 
> I had this PedalPCB board mixed up with another EQD Delay. I actually do have this pedal on my board and use it quite frequently. The oscillation won't immediately onset. Depending on how the 'Delay' pot is set, it will take 1-5 seconds for the oscillation to reach unity volume, and after that it will gradually get louder and then too loud.
> 
> If you really want to make this momentary switch like a 'Hold' feature there are some other things we can do like add clipping diodes at the input of the delay to limit the level, bypass R19 for a quicker onset. But first, try out the mod suggested in the first reply and see what you think.


Exactly. You could use 1 alligator clip to connect the points together, or 2 alligator clips to connect them across a momentary switch. If you like the result, replace the alligator clips with wires.


daeg said:


> I had this PedalPCB board mixed up with another EQD Delay. I actually do have this pedal on my board and use it quite frequently. The oscillation won't immediately onset. Depending on how the 'Delay' pot is set, it will take 1-5 seconds for the oscillation to reach unity volume, and after that it will gradually get louder and then too loud.
> 
> If you really want to make this momentary switch like a 'Hold' feature there are some other things we can do like add clipping diodes at the input of the delay to limit the level, bypass R19 for a quicker onset. But first, try out the mod suggested in the first reply and see what you think.


Ok, so life got in the way unfortunately. But I have built the circuit now and it sounds beautiful. Almost like a tape echo type sound. I just tried connecting lug 3 of level with lug 3 of repeat to a momentary switch with alligator clips. And it defiantly works (goes into oscillation at will) so that’s pretty cool! That’s what I originally wanted to know. Now you have me curious about adding clipping diodes though. I take it this will limit the maximum output of repeats? Or will it distort? I think the last time I did something like this I put a 2m resistor in series…. On the noise ensemble (to tame something) …… what that something was I forget haha. I’m experimenting now.


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## daeg (Oct 16, 2021)

Svenson007 said:


> Now you have me curious about adding clipping diodes though. I take it this will limit the maximum output of repeats? Or will it distort?


Yes to both. Back to back clipping diodes at the input will limit how loud the feedback / oscillation can get. Keep in mind, the reason designers tend to do this is the delay chip (PT2399) distorts in an ugly way, so by creating our own clipping before we reach the clipping threshold of the PT2399 chip, we can get a more pleasing result. I _believe_ the Caroline Effects Meteore does this.

Take a look at this ElectroSmash article: https://www.electrosmash.com/pt2399-analysis


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## Svenson007 (Oct 17, 2021)

daeg said:


> Yes to both. Back to back clipping diodes at the input will limit how loud the feedback / oscillation can get. Keep in mind, the reason designers tend to do this is the delay chip (PT2399) distorts in an ugly way, so by creating our own clipping before we reach the clipping threshold of the PT2399 chip, we can get a more pleasing result. I _believe_ the Caroline Effects Meteore does this.
> 
> Take a look at this ElectroSmash article: https://www.electrosmash.com/pt2399-analysis
> 
> View attachment 17086


Thanks. Yes I’ve heard this, but never had it laid out like that article. That’s helpful. I’ve noticed a few builds that tend to use red led’s at the input of the PT. I assumed that’s what was going on but wasn’t sure…. Is there a simple way to add this as a mod to my momentary oscillation switch you helped me with? I get the theory….. just not the execution. At the stage I’m at there is still a big gap between the two of you know what I mean.  (Seabed delay/deep blue delay….. I think you mentioned you modded yours back in the messages) 

Also have you seen any builds that head the complete opposite direction and distort the hell out of the chip? I think the “Super Weirdo”  by Jupiter is one. Another I suspect is the “slowly melting” pedal by Dirge. A third I actually toyed with, was just some diy guys circuit. Think it is called the Noise Ensamble. It’s basically just the chip being abused (as far as I can tell). Fuzz mixed with modulation and delay…. A very weird and hard to listen too for very long circuit haha. The slowly melting mentioned above is quite cool in an extreme sort of way though. Sort of shoegaze in a box. 

Cheers


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## daeg (Oct 17, 2021)

Svenson007 said:


> Thanks. Yes I’ve heard this, but never had it laid out like that article. That’s helpful. I’ve noticed a few builds that tend to use red led’s at the input of the PT. I assumed that’s what was going on but wasn’t sure…. Is there a simple way to add this as a mod to my momentary oscillation switch you helped me with? I get the theory….. just not the execution. At the stage I’m at there is still a big gap between the two of you know what I mean.  (Seabed delay/deep blue delay….. I think you mentioned you modded yours back in the messages)


Yeah, you've got it.

The next step I was going to suggest was taking a pair of Red LED's and putting them in anti-parallel from Pin 16 to ground, or across Pin 15 & 16. You can probably manage to test this with alligator clips if you have them.

The LED's will clip before the PT2399, but this is a positive and a negative. So as a modder / designer, you'll need to ask yourself the following:

Is it more important to have clean headroom when using it as a normal Delay, or
Is it more important to have the oscillation effect more controlled and have the circuit sound better when it _does_ distort


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## Svenson007 (Nov 20, 2021)

daeg said:


> Yeah, you've got it.
> 
> The next step I was going to suggest was taking a pair of Red LED's and putting them in anti-parallel from Pin 16 to ground, or across Pin 15 & 16. You can probably manage to test this with alligator clips if you have them.
> 
> ...


Late reply, but thanks! I ended up going the “clean headroom when using it as a normal delay” route. But I’ll be experimenting with the other option next. You helped me a lot. Cheers


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