Seabed Delay

[caspercody]

Looks like my old topic on this was deleted from the server transfer.

I got my Seabed delay working, but I have a bad PCB. I had to lift the one side of R16 (closest side to PT2399) and solder a jumper wire from the lifted side and connect to PIN 12 of PT2399.

Why, using a DMM, R16 was connected to PIN 11 and not PIN 12. All I was getting was a clean signal out, with none of the POT's making any difference in the sound.

After a lot of work, I used a audio probe and noticed sound out of PIN 12, but nothing on either side of R16.

But my deelay sound out is not exactly clean, there sounds like a little crackle to the tone. Should this be a clean tone coming out?

With all POT's turned off, clean tone. Once I start to turn up level and delay, I get a crackle at end of note. Mostly when I strum harder.

When I use a audio probe, at PIN 8 it is a fuzzy tone coming out. Is that normal?

Thanks
Rob

 

[phi1]

Were you able to get the DC voltages behaving on the PT2399? If I remember correctly, pin 7,8, and 9 looked strange.

I don't have one PedalPCB's board for this to verify, but I doubt the PCB was actually bad. For one thing, the pic on the Seabed purchase page shows R16 connected to pin 12.

I haven't experienced crackle on the pt2399 builds I've done. I'd imagine if you are sending a really loud signal into the pedal, you could clip the delay portion, since the pt2399 chip runs at 5V. Does it still clip if you lower the input volume you're sending it? Or is the "crackle" your describing something different from clipping?

I've never tried to take audio off pin 8.

 

[caspercody]

Here are new voltage readings:

TL072
1 = 4.26
2 = 4.26
3 = 4.26
4 = 0
5 = 4.26
6 = 4.26
7 = 4.26
8 = 8.53

PT2399
1 = 4.97
2 = 2.48
3 = 0
4 = 0.05
5 = 2.66
6 = 2.41
7 = 0.92
8 = 0.93
9 = 2.48
10 = 2.48
11 = 2.48
12 = 2.48
13 = 2.48
14 = 2.48
15 = 2.48
16 = 2.48

With all controls off clean sound, as I turn the level up, the crackle gets louder. Because going more to wet and less dry signal.

 

[caspercody]

I tried the pedal again, the click or distorted sound happens mostly on low notes or if I strum the higher notes harder. It sounds like it is only the delayed notes making this sound

 

[phi1]

Nice, I think those DC voltages look good as far as I can tell.

I don't have any specific ideas for that click/crackle, other than to keep checking for connections and no bridges on the delay side. And try a different chip if you have one.

Electrosmash has a detailed article about the pt2399 that explains a lot about what's going on in the chip. It's a heavy read, but if you dig in it might be helpful so that you know where are good places to probe (particularly the output stage section). From what I understand, pins 11~14 should all have delayed signal, with each pin being progressively filtered. After pin 14, it is filtered again before being sent to LEVEL 3. If you could figure out which pin the crackle starts on, it might help you find if there's a problem in your build. (Be sure when you probe to use a DC blocking cap). All that said, I haven't myself probed those pins on one of my builds to confirm what it would sound like, just going off the circuit.

 

[geargasstore]

If you have a spare PT2399 around (or even a few) I would try some different ones. Sometimes some sources have suspect ones and they don't quite work well in all pedals sometimes.

 

[gossie21]

Looks like my old topic on this was deleted from the server transfer.

I got my Seabed delay working, but I have a bad PCB. I had to lift the one side of R16 (closest side to PT2399) and solder a jumper wire from the lifted side and connect to PIN 12 of PT2399.

Why, using a DMM, R16 was connected to PIN 11 and not PIN 12. All I was getting was a clean signal out, with none of the POT's making any difference in the sound.

After a lot of work, I used a audio probe and noticed sound out of PIN 12, but nothing on either side of R16.

But my deelay sound out is not exactly clean, there sounds like a little crackle to the tone. Should this be a clean tone coming out?

With all POT's turned off, clean tone. Once I start to turn up level and delay, I get a crackle at end of note. Mostly when I strum harder.

When I use a audio probe, at PIN 8 it is a fuzzy tone coming out. Is that normal?

Thanks
Rob

I have the exact same problem with my Seabed.... clean signal and not of the pots are making any difference in the sound.

I'll have to check the R16 to Pin12 jumper and see if that helps.

 

[phi1]

Before adding a jumper just check for continuity with a multimeter, there’s really no reason to expect the pcb trace isn’t connected.

are you saying you’re getting dry signal through the circuit but no repeats? Do you know how to make/use an audio probe? Look it up, it’s really simple actually).