Deep Blue Delay

[Kost1978]

Another one for you all guys, I've just finished the Deep Blue Delay, bypass sound is OK, when I press the switch no guitar sound is produced, but after a couple of seconds a "distand" sound will get its way to the amp, but it's something like a noise machine: all the knobs are somehow working, modulating this weird and loud sound, but it's not something understandable or controllable, if you know what I mean...
I already tried to "knife" all the traces and also swapped the PT2399, same result.

Only difference from the original layout is I had to use "normal" capacitor for 2n2, 100n and 10n cause I couldn't find the Ceramic ones in these values (but I guess this is not affecting anything in the build).

I know the layout is more than verified, I'm sure is something in my building OR maybe a faulty component, ,I'd like to ask you guys if, based on your experience, something as I described as ever happened before to some of you and maybe pointing me in the right direction...

Thanks again!

[GoranP]

For what it's worth, my build worked right away. I was skeptical about Tayda's 2399s because I got five of them and there were three different markings on them.
Didn't seem to matter, they all worked equally bad/good.
What do you mean by "normal"? I actually used greenies, it was a bit of a tight fit though.

I'll ask you the same thing I always ask with this kinds of problems...do you have an audioprobe? If not, consider putting one together (after all, it's only one cap), work your way through the circuit and see where you lose signal. It has saved me more than one board on its way to the trash bin.

Other than that, I'm not much help.

[ichilton]

equally bad? - is it not very good?

Off topic, but do you have any info on the audio probe thing?

Thanks,

Ian

[GoranP]

ichilton wrote

equally bad? - is it not very good?

Can't say for sure because I have no reference point. I've done very few pt2399 projects and no bucket brigade projects so I have no baseline against which to judge the "sound" of a delay project.

ichilton wrote

Off topic, but do you have any info on the audio probe thing?

My humble belief is that audio probe is never OT in diy :)
Plenty on it on the interwebz:
http://diy-fever.com/misc/audio-probe/
http://billmaudio.com/wp/?page_id=1254
http://www.diystompboxes.com/pedals/debug.html

I've built one that got broken (don't ask  ), nowadays I don't even own one but fabricate one when needed. This is what I do:
- get a regular guitar cable and plug it into an amp.
- take one alligator clip cable, attach one end to the sleeve of the said cable and the other to your circuit's ground point. Usually I attach it to one of the jacks' sleeves because it has enough surface and it's mostly out of the way
- take another alligator clip cable, attach one end to the tip of the cable going to the amp and connect another to one leg of a 100nF cap. I use polybox caps because the plastic box is large enough to hold on to securely. Bend the other leg outwards 90 degrees and that's your probe with which you poke around the circuit. I usually work from the input to the output but you can probe crucial points in the circuit to get the results quicker (for example, opamp output pins are a good candidate).

[ichilton]

Cool, thank you!

[Kost1978]

GoranP wrote

What do you mean by "normal"? I actually used greenies, it was a bit of a tight fit though.

Hi Goran, interesting information regarding the Audio Probe, especially the fact that is possible to build a "temporary one" as you described!!

With "normal CAPS" I mean just the Tayda one I normally use for buiding like this one:
http://www.taydaelectronics.com/2-2nf-0-0022uf-100v-5-polyester-film-box-type-capacitor.html

I'll try to follow your suggestion and build an audio probe, I'm just wondering if it's useful in this situation: I thought an audio probe must be used when no audio signal is coming from the board, in order to trace any fault in the build, in my  case I get a weird noisy signal after a couple of seconds (usually 20/30) the effect is engaged...

Thanks for the help anyway!

[GoranP]

"Normal" cap is what I use in my audioprobe.

There's no right or wrong usage for it. At some point something goes wrong with your signal. Whether it's at the input jack, the footswitch or someplace else along the signal path (seems to be the case with you), you can certainly pinpoint when the things start going south. That narrows down the possible culprits and I see no reason not to do it.

Which schematic will you be following?

EDIT: going over the comments for the DBD, it appears that my memory isn't what it used to be... I indeed had a problem with it and found it using a... wait for it.... an audio probe!

See here:
http://tagboardeffects.blogspot.com/2012/02/mad-professor-deep-blue-delay.html?showComment=1363555573078#c8939570075124454415

[Kost1978]

...and fixed it!!
Guess what? I soldered the input cable from switch to board one hole above the correct position...
As I stated since the biginning, my bulding technique was probably the main cause and I was right!!!
I'm sorry I "disturbed" the forum for that,but at least I learned something new about the "Audio Probe"!:-)
Thanks as usual to everybody and Goran in particular

[GoranP]

A rookie mistake, but I can guarantee that you'll make the same mistake even after the fiftieth build. Just the nature of the beast...

Brainfarts are the name of the game and noone is immune to them...

[Geiri]

I've lost count of how many I've built. At least 350+. I still make the occasional silly mistake. Luckily, I usually debug quickly.

[peavey_xxl]

holy shit  thats a lot of blues!!

[Kost1978]

Just for the record, I'll share a picture of my build, ready to go "on board"!



Have a nice day!

[GoranP]

Nice job!

Are those bike chain links?

[Kost1978]

You noticed, eh?  
Of course they are!
1 bicycle chain + 1 "chain dismounter" for 5€ and you're set for life!

"Long time ago" I found out this little trick to attach pedals on a wood board, not so quick as the velcro system, but IMO "cleaner" and stronger. Anyway, it works fine for me, cause I don't use 9v battery, so my pedals stay always on board (well, recently I'm swapping more and more, cause I found a little blog who's teaching me how to build effects, I have more and more pedals to try out now...).

[GoranP]

I never had an actual board (a few makeshift "bags" but never a board) since I don't play out but if I did, that's what I'd do.