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Another 2 in 1 query :-) Overdrives that stack well together

Started by drolo, December 16, 2014, 03:43:03 AM

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drolo

Lots of 2 in 1 topics lately it seems.

I am planning a double overdrive pedal. The first circuit is already done, it's a kind of OD820 with a mids pot. But I am still looking for a nice second overdrive to put after it. Initially I was going for a Plexi Drive, as I find that it is both a mild overdrive and when boosted with something in front of it becomes a huge marshall monster without adding too much noise. Not surprising to see Wampler use it in his Velvet Fuzz.

The thing is that I am always trying to stay away from circuits relying on parts that are hard to get/expensive and inconsistent, needing much sorting.

I have not found any op amp design yet that breaks up like the Plexi Drive. I tried rat/TS/Shredmaster and similar topologies and they all get very loose and flabby in the bass content when boosted with something. Reducing the bass response does not seem to help much.

Any ideas of an op amp overdrive/distortion that stays tight when boosted?

teknoman2

If I was you I will try to put the second side (higher gain side) of Brian's aristocrat.
Its a bluesbreaker circuit as you know.
Despite that I had very good result when I engage both my maxon od-820 and the second side of aristocrat.
The only draw back is that it lacks a little bit of low end but I believe experimenting with input caps will find good results.

Cheers,
Panos.

murdog47

I've always enjoyed a klon in front of an OCD. I run the Klon clean and use the OCD volume at noon and add gain in from there

Matt

Quote from: murdog47 on December 16, 2014, 04:08:23 AM
I've always enjoyed a klon in front of an OCD. I run the Klon clean and use the OCD volume at noon and add gain in from there
OCD. You beat me to it
Matt

playpunk

Something fuzzy - I like Klon into muffs, myself.


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"my legend grows" - playpunk

drolo

Does any of you have a clip where the OCD can be heard being boosted? What I would like is an overdrive that will compress a lot when boosted. Like the Plexi sounds a lot like a BSIAB when boosted. I have never tried an OCD but from what I heard on youtube I had the feeling it would not do that... will need to give it a try...

I always wondered about the clipping arrangement in the OCD. To me it seems like the second mosfet with the diode is completely superfluous. If I understand the logic, the first mosfet will have on one direction the "special" mosfet clipping character with a drop of 2 or 3 Volts and in the other direction, just a simple diode drop, since there is no diode there to prevent current from flowing through the mosfet's body diode. So that diode drop is already clamping down the signal and the second mosfet that will have a drop of 2 or 3 Volts will never clip...

mgwhit

Quote from: drolo on December 16, 2014, 04:24:43 AM
I always wondered about the clipping arrangement in the OCD. To me it seems like the second mosfet with the diode is completely superfluous. If I understand the logic, the first mosfet will have on one direction the "special" mosfet clipping character with a drop of 2 or 3 Volts and in the other direction, just a simple diode drop, since there is no diode there to prevent current from flowing through the mosfet's body diode. So that diode drop is already clamping down the signal and the second mosfet that will have a drop of 2 or 3 Volts will never clip...

Yep.

RobA

Quote from: drolo on December 16, 2014, 04:24:43 AM
...
I always wondered about the clipping arrangement in the OCD. To me it seems like the second mosfet with the diode is completely superfluous. If I understand the logic, the first mosfet will have on one direction the "special" mosfet clipping character with a drop of 2 or 3 Volts and in the other direction, just a simple diode drop, since there is no diode there to prevent current from flowing through the mosfet's body diode. So that diode drop is already clamping down the signal and the second mosfet that will have a drop of 2 or 3 Volts will never clip...

If I remember what's going on right off the top of my head, it's worse than that. The blocking diode is arranged the wrong direction for MOSFET clipping. So, what you get is in one direction the body diode combined with the GE diode and in the other direction, just the body diode clipping. There isn't any MOSFET clipping involved.

There's a discussion about it in this thread http://www.madbeanpedals.com/forum/index.php?topic=11044.0.
Affiliations: Music Unfolding (musicunfolding.com), software based effects and Rockā€¢it Frog (rock.it-frog.com), DIY effects (coming soon).

Jabulani Jonny

I really like a bluesbreaker into a klone.  I use Aion effects Cerulean into a Refractor quite a bit and it makes a great pair. 
Jonathan

sturgeo

What about one of the rockett pedals? the blue note and animal sound good, both use almost exactly the same circuits IIRC

thesameage

I have a Kingslayer>Pharoah that sounds amazing. There's an SFT ampeg clone in the middle (Jubal's), but that just sounds okay. If I had to do it again, I'd do Kingslayer>Pharoah in a second.

rumbletone

I've yet to find something that breaks up like the Plexi Drive or other similar clipping circuits (unless the device has tubes :-)  ...) . I just received a bag of J201s and will commence sorting shortly ...

Droogie

Kingslayer into Grind's Catch 22 (Timmy)

or

Kingslayer into Bean's Soultrane for a gainier vibe
Chief Executive Officer in Charge of Burrito Redistribution at Hytone Electric

Matt

Quote from: drolo on December 16, 2014, 04:24:43 AM
Does any of you have a clip where the OCD can be heard being boosted? What I would like is an overdrive that will compress a lot when boosted. Like the Plexi sounds a lot like a BSIAB when boosted. I have never tried an OCD but from what I heard on youtube I had the feeling it would not do that... will need to give it a try...

I always wondered about the clipping arrangement in the OCD. To me it seems like the second mosfet with the diode is completely superfluous. If I understand the logic, the first mosfet will have on one direction the "special" mosfet clipping character with a drop of 2 or 3 Volts and in the other direction, just a simple diode drop, since there is no diode there to prevent current from flowing through the mosfet's body diode. So that diode drop is already clamping down the signal and the second mosfet that will have a drop of 2 or 3 Volts will never clip...
Another thought occurred to me...if you like the plexidrive and your only issue is matched jfets, then you should look into the Madbean Swamprat. It's basically a plexidrive with trimpots.
Matt

drolo

I have been toying around with the BSIAB/OKKO Diablo configuration and kinda like it a lot. I am surprised at how well it cleans up when the guitar's volume is rolled back. Most op amp based circuits I have tried just get muddy when you do that.

Seems like I will need to stock up on J201's ... let the gamble begin ...