ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

Let's do something fun

:

4/2/1998 12:19 PM

Let's do something fun

Since this is a DIY forum, I have an idea of something to try here. If y'all would humor my for a couple of posts, I think you'll see where I'm coming from.

The situation is this:

We (the collective) decide that we're going to develop a distortion pedal that emulates a 'cranked' tube amp. I have a multi-step process in mind and once we arrive at a decision for a step, we'll progress to the next. This will also leave open the possibility for the process to fork resulting in multiple designs. The point is to have the design 'evolve' rather than force it and to not just 'go-for-the-carrot' and jump to the end.

So, step one would be what kind of distortion do we want? I'll start with two possibilities: preamp distortion or power amp distortion. Preamp distortion will be primarily asymetrical while power amp distortion will be more symmetrical type clipping.

The details of clipping dynamics and equalization will come after we characterize the type of clipping we are going for.

I would also like to add that it will be easier if one of the requirements is to make this as simple as possible. Although we are starting out attempting to emulate something, what we end up with may be something that just sounds good because it has enough of the 'right stuff'. So limit the analogies to tube amps older than 1965 or so to eliminate models specifically designed to distort.

So, majority wins: what type and why?

E

4/2/1998 12:23 PM
Ever	Re: Preamp Distortion I'm going to try forking this from the start to see how it goes...

4/2/1998 6:26 PM

Ok, I'll bite.

Given the limitations listed and my limited knowledge of vintage tube amps, I would say this isn't a good choice. Most amps of this vintage would be driving the power tubes into clipping long before the preamp tubes begin to clip. I don't think there were too many master volume amps around back then, were there?

With the exception of a AC30TB maybe. Since it has two stages of gain before the tone stack I guess it could start clipping early, but the effect would be small. The main difference is that when the output amp starts clipping, it will hit one side first giving lots of even-order products.

--johng

4/11/1998 4:48 PM
James McDaniel	OK, I've always heard that power amp distortion sounds better than preamp distortion, but how do you get power amp distortion? Where should I set the volume, gain, and master volume?

4/2/1998 12:24 PM
Ever	Re: Poweramp Distortion This seems to be more of the over-driven Fender sound which blues type players might like more.

4/3/1998 12:39 AM

Re: Let's do something fun

Ever:

    While a distortion pedal may have its own tonal character, that sound can be drastically changed as it overdrives the 1965 tube amp it is plugged in to. A classic example of that would be the Boss OD-1 which didn't really have much of a sound by itself, but could overdrive a BF Fender amp into blissful tonalities (including both preamp and power amp distortion).

    So my question as to your project is this: is this pedal to be a standalone device that will produce these tones itself, or are we to look at the synergistic effects when plugged into a good tube amp? As for standalone devices that can emulate tube tonalities the latest generation of software modeling amps and processors are getting pretty damn close.

    Have you checked out the Line6 Flextone and the latest version of their Axis? Those amps really capture the sound and response of many vintage amps cranked up; my gripe is mainly with their CLEAN sounds that lack the warmth of the original amps. That's with the Line6 effects switched off; with the effects on you'd have a hard time telling them apart. Of course with all of the parameters coded into software, there is not much for DIY'ers to play around with in those amps- unless we want to grow our own computer viruses to mod the amps!

Steve Ahola

4/3/1998 9:45 AM

While a distortion pedal may have its own tonal character, that sound can be drastically changed as it overdrives the 1965 tube amp it is plugged in to. A classic example of that would be the Boss OD-1 which didn't really have much of a sound by itself, but could overdrive a BF Fender amp into blissful tonalities (including both preamp and power amp distortion).

Isn't there a difference between an 'overdrive' pedal vs. a 'distortion' pedal? You seemed to be combining the two. I realize they can be both but the discussion started by only mentioning a distortion device.

--johng

Page 1 of 3