Custom Audio Electronics (black cat) OD-1 schematic?

shawsofhell · August 10, 2004, 01:38:53 AM

I have a friend that asked me if I could make him one of these but I have never heard of it can find any schematics. Can anyone help me?

RDV · August 10, 2004, 07:01:10 AM

Quote from: shawsofhellI have a friend that asked me if I could make him one of these but I have never heard of it can find any schematics. Can anyone help me?

http://diyguitarist.com/PDF_Files/BlackCat_OD-1.pdf

RDV

Mark Hammer · August 10, 2004, 09:47:37 AM

Note that since this is essentially one inverting op-amp section driving another, both set for reasonably high gain, I am assuming that choice of op-amp is, if not critical, at least highly recommended. Do not expect to pop in a 4558 or TL072 and have it work optimally. The good news is that the OP-275 is maybe a couple of bucks, tops, and that it is very low noise. The inclusion of a feedback cap in stage 2 will also help to keep hiss and stuff at bay. Given the absence of any explicit clipping devices, I suspect that this unit anticipates driving a tube amp hard.

Paul Marossy · August 10, 2004, 10:37:20 AM

I have tried a JRC4558D, OP275, NTE928M and a few others in mine. I didn't hear a radical difference between any of them. I think that the OP275 did sound a little smoother than the rest did, though.

Gilles C · August 10, 2004, 10:52:39 AM

And if you want a pcb layout, I can send you the one I made and that was once on my site...

Added: I sent it to you anyway, just in case you need it.

shawsofhell · August 10, 2004, 08:37:50 PM

hey can you send it to shawsofhell@hotmail.com

thanks!!!!!!

audioguy · August 10, 2004, 09:01:41 PM

Quote from: Gilles CAnd if you want a pcb layout, I can send you the one I made and that was once on my site...

Added: I sent it to you anyway, just in case you need it.

Can I get one of those?

Gilles C · August 10, 2004, 10:03:21 PM

Done!

shawsofhell · August 11, 2004, 12:38:54 AM

no one near me sells the op275. will the sound change much if i used a 4558 or other dual op?

Samuel · August 11, 2004, 01:09:59 AM

Question this schematic brings up:

I'm a little bit confused by the opamp arrangement...probably just my inexperience, but is applying the DC bias voltage to the + input of the OA pretty standard? I feel like I've never seen that before, and I am unsure of how that functions. Does the input signal get summed with the DC before the OA does any amplification? and how would the feedback resistor section function if the OA output is affected by a DC bias that the original signal did not have?

I guess I have some fundamental questions about the nature of OAs in general...

TIA

RDV · August 11, 2004, 05:26:48 AM

Analog Devices.com has a free samples program similar to Ti's. I hated that Blackcat OD-1 thing though. Opamp clipping. EEEEEWWWWW!!!! I was glad I built instead of bought. I modded that thing out of existence. Of course you might love it.

RDV

Paul Marossy · August 11, 2004, 10:38:36 AM

shawsofhell-

A 4558 should work fine. It did for me...

RDV-

There are a bazillion circuits that use opamp clipping that are loved by countless guitarists. :lol:
Take the Shaka Tube for example. Opamp clipping followed by a preamp tube section. I think that it is a great sounding pedal, I use it all the time.
To each his own. :wink:

WGTP · August 11, 2004, 11:37:11 AM

I don't know much about opamps or electronics for that matter, but there seems to be at least 2 ways to do the feedback look deal. Â Take a loop at the Muff Fuzz opamp version and contrast it with the Tube Screamer/Distortion + types. Â I love the modded Muff Fuzz/Mockman I have. Â Check out the Mockman at ROG and try mixing diodes.

If you don't like the circuit as is, try some diodes in the 2nd feedback loop. Â Lot of variety available, or checkout Mark Hammers Chaos (I think that is the right name) or the Mosferatu in the schematics section. Â

cd · August 11, 2004, 11:55:56 AM

Quote from: RDVAnalog Devices.com has a free samples program similar to Ti's. I hated that Blackcat OD-1 thing though. Opamp clipping. EEEEEWWWWW!!!! I was glad I built instead of bought. I modded that thing out of existence. Of course you might love it.

RDV

I thought it sounded fantastic driving a cranked up Marshall. Into a clean Fender, not so good

Paul Marossy · August 11, 2004, 12:00:38 PM

Scott Henderson used to use one as his main distortion, I think to push his amp harder. I always thought he had a great tone on any album that I have heard. I know that he has used Marshall cabs with his CAE amp head. He has a few other amps as well.

cleanroom · October 21, 2005, 12:30:23 AM

Quote from: Gilles C on August 10, 2004, 10:52:39 AM
And if you want a pcb layout, I can send you the one I made and that was once on my site...

Added: I sent it to you anyway, just in case you need it.

Any chance I could get a copy of this also?

The Tone God · October 21, 2005, 12:40:01 AM

Quote from: cleanroom on October 21, 2005, 12:30:23 AMAny chance I could get a copy of this also?

Have you checked the date on the thread ? Your more then a year late.

Andrew

Gilles C · October 21, 2005, 07:26:56 AM

You're in luck, I still had the files on my hard disk.

I sent it

Gilles

Bernardduur · October 21, 2005, 09:17:40 AM

Speaking of Black Cat; anyone has the Bass Octave Fuzz schematic?

I believe it is a Maestro Brassmaster; is it a perfect clone or is it modded?

bass_econo · October 21, 2005, 09:18:35 AM

Well since you still have it... Could I get it as well? I've become a big fan of opamp distortion.

News:

Custom Audio Electronics (black cat) OD-1 schematic?