How to design the different stages of a multi stage distortion / preamp Pedal ?

[Vivek]

I request your guidance on design of the different stages of a multi stage distortion / preamp Pedal ?

Any hints on range of how much of duty cycle should be chopped at fist stage and how much at next stage ?

Does this make sense :

First Stage :
Bass cut before entering this stage
slight clipping

Second stage
No need for bass cut since it has already been cut
cut the treble before entering this stage
More drastic clipping at this stage ?
Cut the treble again upon exit from this stage

Anyone has graphs ? Simulations ?

Thanks

[Vivek]

I made an LT SPICE file to try and analyse the Pete Cornish Crunch CC-1 as traced by AION.

I can offer the LT SPICE file to anyone who is interested, but I dont know how to attach files here.

It has 2 gain stages

Each has a huge compliance resistor in series with the diodes.

I will post my analyses of the CC-1 soon.

[Steben]

I made an LT SPICE file to try and analyse the Pete Cornish Crunch CC-1 as traced by AION.

I can offer the LT SPICE file to anyone who is interested, but I dont know how to attach files here.

It has 2 gain stages

Each has a huge compliance resistor in series with the diodes.

I will post my analyses of the CC-1 soon.

you can click on the blue "add image to post" underneath the text box if you want to download directly from pc

[Vivek]

Thanks

So no way to attach the *.asc files except post them as text ?

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TEXT 16 -400 Left 2 ;MAD PROFESSOR SWEET HONEY OVERDRIVE\n \nhttps://pcbguitarmania.com/wp-content/uploads/2018/11/Mad-Honey-Building-Docs.pdf\nhttp://revolutiondeux.blogspot.com/2010/06/mad-professor-sweet-honey-overdrive.html

[Steben]

I request your guidance on design of the different stages of a multi stage distortion / preamp Pedal ?

Any hints on range of how much of duty cycle should be chopped at fist stage and how much at next stage ?

Does this make sense :

First Stage :
Bass cut before entering this stage
slight clipping

Second stage
No need for bass cut since it has already been cut
cut the treble before entering this stage
More drastic clipping at this stage ?
Cut the treble again upon exit from this stage

Anyone has graphs ? Simulations ?

Thanks

I'ld add two elements:
- cascaded high gain: the total of following cap coupled gain stages makes for bias shifting if the clipping of the stages is assymetric. This gives a classic multistage tube preamp sound
- keep cutting bass and very high end before each clipping stage

[Vivek]

I'ld add two elements:
- cascaded high gain: the total of following cap coupled gain stages makes for bias shifting if the clipping of the stages is assymetric. This gives a classic multistage tube preamp sound
- keep cutting bass and very high end before each clipping stage

Thanks !!!

Please help me to understand

A) Are there time constants involved with the bias shift on the coupling capacitors following asymmetrical clipping? do you have an idea of the normal range of these time constants ?
are they in the range of few cycles
or part of a note
or after many notes (somewhat like a sag)

B) Suppose clipping does not create subharmonics (No intermodulation products) and we already cut bass before first clipping stage, is there a need to cut more bass before 2nd and 3rd clipping stages ?

[Vivek]

Is there logic to the general wisdom of

slight clipping stage first, harder clipping stages later on

[bluebunny]

So no way to attach the *.asc files except post them as text ?

Use the [code] tag (the # button).  Then we don't have to scroll through yards of code.  Like this:

Code Select Expand

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TEXT 16 -400 Left 2 ;MAD PROFESSOR SWEET HONEY OVERDRIVE\n \nhttps://pcbguitarmania.com/wp-content/uploads/2018/11/Mad-Honey-Building-Docs.pdf\nhttp://revolutiondeux.blogspot.com/2010/06/mad-professor-sweet-honey-overdrive.html

[Vivek]

Thanks, I edited my post accordingly !!!

[Steben]

Is there logic to the general wisdom of

slight clipping stage first, harder clipping stages later on

A VOX AC30 or Marshall 18W is the opposite: power amp is non feedback cathode bias with very gradual clipping, the preamp triode stages clip harder.
Just as some like a distortion or fuzz in front of an overdrive pedal.

[PRR]

A) Are there time constants involved with the bias shift on the coupling capacitors following asymmetrical clipping? do you have an idea of the normal range of these time constants ?
are they in the range of few cycles or part of a note  or after many notes (somewhat like a sag)
B) Suppose clipping does not create subharmonics (No intermodulation products) and we already cut bass before first clipping stage, is there a need to cut more bass before 2nd and 3rd clipping stages ?

Not cheap yet worth the price if you insist on asking such questions:

Guitar Amplifier Overdrive by Ulrich Neumann, Malcolm Irving

I have just noticed that Neumann published a similar but cuter-covered book this summer:
Guitar Amplifier Design: Tubes and Semiconductors Play Together

[LightSoundGeometry]

A) Are there time constants involved with the bias shift on the coupling capacitors following asymmetrical clipping? do you have an idea of the normal range of these time constants ?
are they in the range of few cycles or part of a note  or after many notes (somewhat like a sag)
B) Suppose clipping does not create subharmonics (No intermodulation products) and we already cut bass before first clipping stage, is there a need to cut more bass before 2nd and 3rd clipping stages ?

Not cheap yet worth the price if you insist on asking such questions:

Guitar Amplifier Overdrive by Ulrich Neumann, Malcolm Irving

I have just noticed that Neumann published a similar but cuter-covered book this summer:
Guitar Amplifier Design: Tubes and Semiconductors Play Together

Paul, those books i was looking for ..they are like 100+ used all over the nets; I looked on the sites you gave me and found nothing in a book similar for under 100 used. a book similar to the one we used in school will go for 100-200 easily if it can be found. what i mean by that is the step by step examples of everything from the outer shell of an atom to digital I. it was so thorough in detail. I might have to shoot the old professor a email and see if can tell me the publisher ( or the book store on campus)

I still have  lot of my notes ..i have a lot on logic gates and Boolean algebra lol ..all looks chinese and greek to me now