What is the Vemuram Karen (Kadundra) based on?

[HamishR]

I can't believe it's an original design. I've been experimenting with the circuit and getting some decent results. Anyone see where it's come from? I can't put my finger on it.

 

[jwin615]

I can't believe it's an original design. I've been experimenting with the circuit and getting some decent results. Anyone see where it's come from? I can't put my finger on it.

Backwards YATS(tone control in first stage)with hard clippers instead of soft?

 

[cdwillis]

Very similar to an OCD with a couple added/tweaked parts.

 

[HamishR]

The OCD was the closest I could think of - maybe you're right!

 

[HamishR]

Just noticed that the Maxon SD-9 has a few similarities... My guess would be SD-9 > OCD > Karen. They all have a resistor coming from pin 1 of the IC to two diodes in parallel with a 10n cap all going to Vref and another resistor going to pin 5. I think @cdwillis got it! There are too many similarities with the OCD.

The cool thing for me is that by reducing the gain in the Karen you can get an excellent OD which I think sounds better than any of them.

 

[cdwillis]

I haven't built it, but that Width control on the Karen looks interesting. Since it and the resistor it's hooked up to in series are in parallel with the drive pot, it's controlling the overall gain range.

Reminds me of when I was messing with the OCD type circuit on my breadboard and I had an idea to use a linear 1m pot for drive then swap a smaller resistor in parallel for a low gain mode. I only had logarithmic pots at the time and I ended up taking it apart to build a big muff, so I never got around to trying it.

 

[HamishR]

I haven't built a Karen in stock form but close to it. It is definitely one of the better sounding high gain pedals I have heard. I'm quite impressed with it. It sounds a helluva lot better than any OCD I've heard.