Danelectro - DJ-04 Corned Beef Reverb  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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jovesdies
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Post by jovesdies »

Hi,
this is the corned beef schematic. It's another PT2399 delay with fixed time and feedback. I've inserted feedback and time controls and changed C19 , the filter cap cutoff from unknow value to 10nf for a better low pass. R16 is 33k in the original but I've changed to 47k for a better noise performance. It's a great deley pedal with low repetition distorted noise (and only at max delay settings). The transistor is a generic 2N3904 or 2N5088. It's a buffer inserted at the pt2399 output.
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corned beef.pdf
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mxaniac
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Post by mxaniac »

Based on a helpful PM from jovesdies and the posted schematic I'm hoping if I do what is marked up below I'll achieve the same mods. I might have a different revision PCB though. It looks like my R14 and R16 values are different. More concerning is that as far as I can tell where the schematic has C17 then R15 I have R15 (R109) then C17 (C107). Seems like my C18 (C109) and R22 (R121) are swapped too. Any input before I cut traces and drill holes?

Thanks,

Rich
Corned Beef PCB Mods.jpg

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mxaniac
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Post by mxaniac »

Since my last post was completely wrong I felt compelled to update it. Not only did I misread several designations on the posted schematic I think I have a different version of the PCB.

This is the first board I ever traced so it's pretty much guaranteed to have mistakes.
schematic.jpg
schematic.jpg (31.47 KiB) Viewed 1474 times
Here are the mods I made:
Corned Beef v2.jpg
I attached the pots like this:
pots.jpg
Final result:
illuminati.jpg
It's still a pretty poor reverb and I'm not even sure I implemented the feed pot correctly but before the modifications I could only get 1 combination of settings that even remotely sounded like reverb. Now I can come up with a few different settings that sound reverbish.

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steliosp.
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Post by steliosp. »

Hi

I'm pretty new to this so excuse my ignorance. If i wanted to make a clone of the original pedal without the mods you two kindly provided, could i do it with your previous schematics. Am i right to assume that the top part of your drawing replaces the tl072? I also guess there is a 2nd pcb that is not pictured.

Do you guys have a more complete and comprehensive schematic of the full pcb, including pots and dpdt locations and wiring? The dj 4 is no longer available and would love to tackle a project like this.

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mxaniac
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Post by mxaniac »

steliosp. wrote:Hi

I'm pretty new to this so excuse my ignorance. If i wanted to make a clone of the original pedal without the mods you two kindly provided, could i do it with your previous schematics. Am i right to assume that the top part of your drawing replaces the tl072? I also guess there is a 2nd pcb that is not pictured.

Do you guys have a more complete and comprehensive schematic of the full pcb, including pots and dpdt locations and wiring? The dj 4 is no longer available and would love to tackle a project like this.
It has a 072 in it, I just represented them as 2 components because the symbol was already available in TinyCAD. The schematic isn't complete as you've noticed and yes it has a second board. I don't have a more complete schematic. Since far better schematics are posted it wouldn't make any sense to build this pedal. It isn't a good pedal by any means. If I find the time I'd like to build the All Star Reverb posted on this site, it sounds like a much better effect.

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