Help with Electric Druid DigiDelay

[ferdinandstrat]

Hey I just finished building the Digidelay and it sounds amazing. Sadly I have a small issue, the "splash" feature doesnt work and for some reason I have to press the bypass switch twice to turn the delay off. Any help?

[bluebunny]

Did you use momentary switches for both bypass and tap?

[ferdinandstrat]

Yes

[ElectricDruid]

Maybe check the 10K pull-ups on those pins. If they were floating about, some weird stuff like that might happen.

Aside from that, are the switches any good?

Tom

[ferdinandstrat]

Well, the switches are good, I ordered them from small bear. I guess reflowing the joints wont hurt

[ElectricDruid]

You can test if the problem is the switch by shorting across the pads on the PCB where the switch attaches. It's a bit tricky since it's hard to make a reliable connection, but it works and gives you an idea if you fiddle about a bit.

If the pedal works ok like that, most likely is you've overheated the switch soldering it.

HTH,
Tom

[ferdinandstrat]

I tried reflowing the solders and replacing the IC's just in case, nothing.

I desoldered the wires from the switch and tried to see what happens when I simply short the wires. Sometimes it turns off the first time I touch and others it doesnt, does this mean the switch is bad?

[ferdinandstrat]

Question, I've seen in the pictures on the site that the jacks used were plastic with no chassis ground. I used plastic jacks, which means I do have chassis ground, could that affect anything?

[potul]

Did you use NC or NO switches?

[ferdinandstrat]

Pretty sure that NO

[potul]

Pretty sure that NO

Then I suppose it's ok. I mentioned it because this type of behaviour is typical from using latching switches instead of momentary, or using NC instead of NO.

Looking at the schematic NO seems to be ok, although I didn't check the code.

Mat

[ElectricDruid]

Question, I've seen in the pictures on the site that the jacks used were plastic with no chassis ground. I used plastic jacks, which means I do have chassis ground, could that affect anything?

A few people have been thrown a bit by that photo. I can reveal the real reason for that unit having plastic jacks though: I mis-drilled the holes, and the larger plastic nuts on the outside covered up the damage!! It was always intended to use open-frame metal jacks in which case the chassis would be grounded. There's no problem with that.

Also the switches should definitely be normally open. Normally closed will confuse me and the pedal.

HTH,
Tom

[ferdinandstrat]

Thanks for the help my friend, I ordered some new switches.

Trust me I have so many issues with misdrilled holes, the amount of times I repurpused enclosures is ridiculous.

[Jfast]

Hi i hope i can borow the topic.

I bought a Druid Digidelay kit and after building it I cant get it to work. The guitar sound goes through unmodified. The led responds to the tap and to the bypas but no efect to guitar at all. 

This is not my first Diy pedal kit but i cant figure out the problem on this one. Every info would be helpfull. I did the voltage test, double checked the resistor and capacitator values, diode orientation...

Thanks in advance and sorry for bad english  living in 

[ElectricDruid]

You could try checking these points with an audio probe:



https://electricdruid.net/wp-content/uploads/2018/02/DigiDelayDebuggingPoints.png

(1) is the pre-delay filter. You probably have clean signal there. You should!
(2) is the post-DAC differential amp. This should the delayed signal direct for the chip.
(3) and (4) are the two post-delay filters. You should have delayed signal at both of these points too.

An error in (2), (3), or (4) will kill the delayed signal before it reaches the final mixer. It's possible (quite easy, even) to mix up a capacitor value in the filters and remove *all* of the signal instead of only some of it!

HTH,
Tom

[Jfast]

Hi
Thanks for the info just made a test and on the first probe i get a clean sound, second probe i get a delay efect and on 3,4 nothing i also changed the TL02 where the second probe is and same efect. I asume that teh C5 is wrong but i checked the value and it is 1nF (1nK100). Could there be something else wrong?

[ElectricDruid]

Hi
Thanks for the info just made a test and on the first probe i get a clean sound, second probe i get a delay efect and on 3,4 nothing i also changed the TL02 where the second probe is and same efect. I asume that teh C5 is wrong but i checked the value and it is 1nF (1nK100). Could there be something else wrong?

That's all good news. If you're getting delayed signal at (2) then the digidelay processor is fine and everything's working. If you've got sound at (2), it can't be C5 either, because that is part of the circuit around that op-amp (have a look at the schematic: https://electricdruid.net/wp-content/uploads/2016/10/DigiDelay-Schematic-Pg1.jpg)
If the signal doesn't get to (3), you're probably looking for a mistake in that first post-delay filter. So R12, 13, 14 or C6 or C7. Could be a wrong component, could be a short, could be a dry joint.

HTH,
Tom

[Jfast]

Hi Thanks for all the help realy today i made it it works now. It was a faulty Cap so the signal was cut there. im Realy gratefull. If you are in Munich some time you get a free beer from me.

[ElectricDruid]

Glad to hear you got it sorted. Good work!

Munich is fine place to drink beer! If I'm ever over that way...

T.