DIY Solid State Overdrive - Soft Clipping?

[tbassist4]

Hey everyone,
I know you can't properly "overdrive" a solid state amp, so I was wondering how you'd achieve this compression + soft clipping in a DIY pedal build. I would appreciate advice or links to schematics that are designed to work with SS amps.

Tyler

[B.C.]

Originally Posted by tbassist4

Hey everyone,
I know you can't properly "overdrive" a solid state amp, so I was wondering how you'd achieve this compression + soft clipping in a DIY pedal build. I would appreciate advice or links to schematics that are designed to work with SS amps.

Tyler

Hi T,

Soft clipping is achieved via an Op amp with two diodes in the feedback loop. This is a common topology, found in the Tubescreamer(symmetrical clipping) and Boss Super Overdrive(asymmetrical clipping.)

Here is a link to it. http://www.tonepad.com/getFile.asp?id=81

Hope this helps.

[tbassist4]

Originally Posted by B.C.

Hi T,

Soft clipping is achieved via an Op amp with two diodes in the feedback loop. This is a common topology, found in the Tubescreamer(symmetrical clipping) and Boss Super Overdrive(asymmetrical clipping.)

Here is a link to it. http://www.tonepad.com/getFile.asp?id=81

Hope this helps.

Exactly was I was looking for. Thanks!

Tyler

[tbassist4]

So, silly question, do I need to modify anything for this to work for bass, or will it work as is?

[B.C.]

Originally Posted by tbassist4

So, silly question, do I need to modify anything for this to work for bass, or will it work as is?

Well, in my experience, the Tube Screamer Topologies sound a little thin, ie they loose a lot of bass responce. What you can do is increase the input capacitor to a lower cutoff frequency. If that doesn't work, you can try the output capacitor.

[tbassist4]

Okay, sounds good, so what's the best way to test which cap I like better? I've done some real basic pedals before, but nothing where I've had to mess around with the schematic. Do I use something like alligator clips and switch them out until I find one I like?

[B.C.]

Originally Posted by tbassist4

Okay, sounds good, so what's the best way to test which cap I like better? I've done some real basic pedals before, but nothing where I've had to mess around with the schematic. Do I use something like alligator clips and switch them out until I find one I like?

There are standoffs you can use. I assume your using a pcb so I would solder two standoffs where the leads would be and swap to taste.

[tbassist4]

Awesome, thanks for taking the time to help me out.

[B.C.]

Originally Posted by tbassist4

Awesome, thanks for taking the time to help me out.

No problem, if you need anything else let me know.

[tbassist4]

In this circuit there's a section where you can choose whether you want symmetrical or asymmetrical clipping based on the number of diodes involved. If I wanted to add a switch to choose between these what kind of switch would I use?

[B.C.]

Originally Posted by tbassist4

In this circuit there's a section where you can choose whether you want symmetrical or asymmetrical clipping based on the number of diodes involved. If I wanted to add a switch to choose between these what kind of switch would I use?

I would use a DPDT switch. That way, you solder a diode to the top two leads(watch for direction), a normal connection for the middle two leads and then a jumper wire between the last two.

[Hookus]

Check out a Red LLama clone as well. Easy DIY build that sounds great on bass. Can be very tube-like.