Prescription Electronics - Depth Charge  [traced]

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Re: Prescription Electronics - Depth Charge

Postby destro » 19 Oct 2009, 21:14

soulsonic wrote:
Sound pretty nice too; though I might want to increase the value of R9 because the clean blend seems to overpower the fuzz too easily.


Agreed. Built it from the schem and pictures and it works! The clean is too overpowering, though. You have to run it all the way to wet for it to seem blended.
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Re: Prescription Electronics - Depth Charge

Postby soulsonic » 20 Oct 2009, 00:16

destro wrote:
soulsonic wrote:
Sound pretty nice too; though I might want to increase the value of R9 because the clean blend seems to overpower the fuzz too easily.


Agreed. Built it from the schem and pictures and it works! The clean is too overpowering, though. You have to run it all the way to wet for it to seem blended.

Yep, that's how it is, so you must have gotten it all correct! :lol:
Increasing R9 to something like 470k helps a bit. Maybe the best thing to do would be to try a different blend circuit entirely. The kind that has the blend control's wiper going to ground would probably work better, but you'd need to add some additional mixing resistors to the circuit and move some stuff around.
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Re: Prescription Electronics - Depth Charge

Postby soulsonic » 20 Oct 2009, 00:31

This is what I'm talking about for a better blend circuit. This arrangement allows for full clean or full fuzz at its extremes.
Values would need to be determined to see what works best.
Also, in the case of the Depth Charge, it might be better to have a large bipolar cap in series with the wiper to ground so that it doesn't upset any DC biasing of the following stage.
SimpleBlend.BMP
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Re: Prescription Electronics - Depth Charge

Postby destro » 20 Oct 2009, 03:05

Well, I threw a 500k pot in there and ended up going with 390k. Any more and it seemed that there was a noticable volume loss. Mine doesn't get much higher than unity. So I did a little digging and found a common fix by throwing a capacitor in parallel with the recovery stage's emitter resistor. I went with a 100uf. Got less clean to blend and more volume now and a stupid chirping noise when cranked too hot, but overall, worthwhile mods for my taste. I've hand drawn a perf layout if anyone wants to do it up right, let me know and I'll send you a scanned copy.
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Re: Prescription Electronics - Depth Charge

Postby GodSaveMetal » 04 Nov 2009, 17:38

Please:
Can anybody post an schematic with a PCB for etching this fantastic pedal!!!!!!!
Please I beleive that you can!!!!!!!!!!! :applause: :applause: :applause:
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Re: Prescription Electronics - Depth Charge

Postby gkoerselman » 22 Nov 2009, 22:29

I build this one the other day and wanted to share my PCB, but I realised I had forgotten the 22u filter cap on the +9V so I've redone the PCB layout a bit. For my build order I also messed up the 0.22u elec. caps so I've installed 220n non polarity for the time being... Please note that I dropped the protection diode!

Any comments or corrections are as always appreciated. PM me with your e-mail address if you want my Eagle files.

Thanks to soulsonic for the schematic!!! :applause:
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Re: Prescription Electronics - Depth Charge

Postby destro » 12 Dec 2009, 04:10

My perf layout based off schematic and pics posted in this thread. Mine works great though I would verify as you build. Sorry it took so long. Put it together tonight. Diylayout creator is awesome. Will use more in the future. Enjoy!

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Re: Prescription Electronics - Depth Charge

Postby lohstah » 25 Dec 2009, 14:15

belated thanks for posting that perf layout, destro ! :thumbsup
what transistors did you use in your build ?

cheers,
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Re: Prescription Electronics - Depth Charge

Postby destro » 29 Dec 2009, 04:07

Thanks man! I figured, what the hell, and went with the 2n3707's from mouser. They were pretty cheap. Can't remember the HFE range but I got enough to where they were all pretty close together. I find myself wanting more of the fuzz in the blend option, but I haven't opened it back up to test a soulsonic blend idea.
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Re: Prescription Electronics - Depth Charge

Postby GodSaveMetal » 12 Jan 2010, 14:55

Excelent Man!!!! can be a replace of 2N3707 perhaps the "BC458 o 459 o 558 o 2N4904 o 2N5088, 5089 o others" it will work with the ever be 2SC828?????, Thanks a lot for the PCB. :applause: :applause:
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Re: Prescription Electronics - Depth Charge

Postby shaggy45 » 20 Mar 2018, 21:35

Hello everyone,

i was wondering if one of fine folks could help me out. I built a vero version of this pedal and it doesn't work right. I've looked over the schematic and the layout
and can't seem to figure out whats wrong. It's from a unverified layout. I've built a good bit of pedals, but i'm just now getting into the mechanics of this stuff and this
would be a great opportunity to learn something about spotting errors. The problem with the pedal is that the blend does something, its not blending though. The tone is acting as a volume knob.



layout is here:

http://guitar-fx-layouts.42897.x6.nabble.com/file/n20522/Depth_Charge.png


Q1 and Q2 are the same, but then Q3=Q6, Q4=Q3, Q5=Q4 and Q6=Q5 (layout=schematic).

Any help would be greatly appreciated.
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Re: Prescription Electronics - Depth Charge

Postby destro » 21 Mar 2018, 03:10

Go through the layout with the schematic posted a few posts above. Double check your wiring. Insure the transistors pinouts are right. Check polarity of caps. Then check vero traces for continuity. If you take your time and go through it methodically you will find the problem. Debugging is tedious, but you will learn from doing it.
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Re: Prescription Electronics - Depth Charge

Postby shaggy45 » 25 Mar 2018, 16:58

I gave up on the vero and etched a board from the image above. Its so close but not there yet. it works but the low end is just not there compared to a real depth charge. the blend didn't work until i connected tone 2 to blend 1. this thing is gonna drive me nuts lol
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Re: Prescription Electronics - Depth Charge

Postby shaggy45 » 27 Mar 2018, 17:19

i opened up my original depth charge today and took a peek. mine doesn't use 1n270's it has what i can make out to be 1n4933 instead. i don't have any of those on hand, but went ahead and ordered some. does anyone think that changing the 1n270 to 1n4933 would make a huge difference on the sound of this thing? maybe my 1n270's are trash? i got them from tayda. any thoughts?
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Re: Prescription Electronics - Depth Charge

Postby shaggy45 » 30 Mar 2018, 16:15

got my 1n4933 diodes today. didn't fix it. seemed to exacerbate the issue. it's just missing something. I'll keep messing with it.
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