Chopped Boss OC-2 (compact layout)

[YerayM]

With only two knobs I refused to use anything bigger than a 1590B so I draw my own layout and made it 1590B friendly at the cost of standing resistors and two component shared holes. Based on the schematic by Ben Milner with the opamps in the LM324 reordered.



Built and verified:

[jsetov]

Thanks for doing this!! I've already started on it and am really excited to get it on my pedalboard. I do have a question though. For the standing diodes I wasn't sure if the white or black was the cathode end of the diodes. I had trouble seeing it on the 1n914's on the gut picture you posted of your build. Am i right in assuming that the white = cathode? It look's like that's the case on the 1n4001, but i thought i'd ask just in case.

[YerayM]

You have it, for the standing diodes the white face is the cathode and the black face is the anode. Hope you enjoy it.

[jsetov]

Thanks a ton, I really appreciate it!

[IvIark]

Great job on this

[nicowaddle]

Super, I'm gonna do it quickly !
Only one thing : it seems that, for the 1N4001, the white face is anode, isn't it ?
I compared with http://guitar-fx-layouts.42897.x6.nabble.com/Cut-Boss-OC-2-single-octave-down-version-td4960.html#a11026

[YerayM]

Just to be safe, the white face is the strip side of the diode, I hope this is clear enough

[nicowaddle]

Yes,you're clear enough ;-)
Thanks !

[oasisman]

I built this but have no lm324 ic's I just used another tl074.  How important is the lm324 to the circuit its just a standard quad op amp isn't it?

Also I used a 2n5457 for the jfet as that's all I have.

The circuit passes signal fine, pots work but I can really on get the octave sound on the low e and then that's only when I wack it hard.

I use to own an original oc2 years ago and I remember how bad the tracking was on it.  I can replicate that but like I said only on top string when I hit it hard.

[nicowaddle]

I did it with 2 TL074 too and I'm not really satisfied with both the tracking and the octave tone.
I'm waiting for LM324 ic. I will tell you if changing the ic solve the problem .

[oasisman]

I wouldn't be too optimistic about the tracking, like i said i had the original and the tracking was always quite glitchy.  that's probably why they brought out the oc3.

on mine the octave is barley noticeable, apart from the top string and then its nothing like the old oc2.  hopefully it will work like it should with the correct quad op amp!

I look forward to hearing how it goes for you.

[nicowaddle]

Tried with LM324. Not satisfied.
Mine doesn't sound like an OC-2 (I've got one). The original octave tone is medium but this is too "fatty".
I will try to do another one in a couple of weeks.

[doxasound]

Built this a few days ago and mine tracks well! Not sure why everyone else is having issues :(

I subbed the 1n914 with "modern" 1n4148, but other than that kept to the layout and it tracks really well! To the point where i can play some chords/triads and it sounds usable!

So anyone that's wondering if this is good to build, it's GREAT to build. Go for it!

[GrooveChampion]

Could the issue be the J201 biasing?

[GrooveChampion]

Built it and had a headache with the diode orientation cos I didnt read the thread. The tracking on the A and E strings on my bass is a bit underwhelming but it sounds fat and fantastic. 10/10 would build again.

[iiimonfire]

Just built this and MAN is it FUN! Well done!

[iiimonfire]

Several years later and I am back to report that this pedal is still my go-to octave pedal. There's still a small learning curve you've got to figure out for the tracking, but I throw this on after a BMP, with the the tone knob at about 75% on my PJ Jazz bass, and the octave down is simply :chefs-kiss:. I would think of trying out other octave pedals on my rig, but nothing else seems to make as much sense to me as this.