Layman's question about clipping order

Started by screamersusa, November 11, 2013, 11:38:15 AM

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screamersusa

using 3 or 4 stages after a clean gain stage, in what order would be the smoothest clipping?
Stage 1 starts first followed in order by the others?
Stage 1 and stage 3, then 2 and last 4.

2nd question, if you want a little compression for fast runs, how to you
drop the gain or saturation point  on lets say stage 2. I ask because it seems like many of the
circuits I find are maxing the gain potential of the jfet and then clipping it.
I would suspect that lowering the voltage and rebiasing only the desired stage
would accomplish this with less noise than a voltage divider.
(Similar to what an Engl does).


midwayfair

Most of the time you want to have less clipping early in the circuit. When you clip a wave form, you add harmonics and bring up the noise floor. If you clip the wave severely early on and then amplify it a lot more to clip it again, you'll get more noise, and chances are you might end up with some harsh intermodulation. That's by no means a "rule" though. You should do what sounds good to you. The Big Muff Pi, for instance, has two stages that clip roughly the same in order, and even though it has a high noise floor, there is enough treble filtering to keep the sound from getting harsh. So you can also look into using a lot of filtering to make the signal behave.

For the compression:
First, dynamic range compression is an inherent aspect of clipping. If you are talking about automatic gain reduction, then knowing the proper terms will help you find what you need.

Second, sending JFETs (and other transistors) into cutoff ALREADY makes them a little squishy/saggy. The Runoff Groove Supreaux Deux does this really well. The Mosrite fuzz somewhat famously does this, too. So you might not need to get any fancier than building a multi-stage distortion to get what you're looking for.

There are MANY ways to do automatic gain reduction in a transistor circuit. I would suggest researching some compressors. But in brief:

Aquataur did a small compressor circuit in the Runoff Groove Umble that works okay -- http://user.eduhi.at/aquataur/aquataur/musicstuff/umble.html

Another good way is to use a rectifier and FET to reduce the transistor gain. The Bearhug compressor in my signature shows a way to do this with a MOSFET, which will work just as well on a JFET, but with less gain. There are also many ways to affect gain or level with a light dependent resistor that are a little less restrictive.
My band, Midway Fair: www.midwayfair.org. Myself's music and things I make: www.jonpattonmusic.com. DIY pedal demos: www.youtube.com/jonspatton. PCBs of my Bearhug Compressor and Cardinal Harmonic Tremolo are available from http://www.1776effects.com!

screamersusa

I'm going for a well balanced distortion circuit not AGC.
The Supreaux is kind of what I'm thinking. The j201's placement
after cleaner higher headroom fets makes sense.
That compressor of yours is quite cute considering I dont really like
full blown compressors on guitar.