[thesteve]

Originally Posted by What5647

also, i see no reason for a limit at a set number of stages, with different stages you could easily change the number of stages needed to get a full suqare wave.

This is sorta what I'm thinking. Suppose there was no variable "gain circuit"...what if all you had were stages? Why couldn't you spread your stages out and have 20 different, and sequentially heavier gain stages?

[What5647]

yeah, i you and i are thinking along the same lines. i'd say the "reason" you couldn't is simply cost since you need at least one transistor or tube for each gain circuit (not so sure on the tube part-they don't teach how tubes work anymore. atleast not were i go to school) the costs and complexity would get pretty high pretty quick.

[thesteve]

Originally Posted by What5647

yeah, i you and i are thinking along the same lines. i'd say the "reason" you couldn't is simply cost since you need at least one transistor or tube for each gain circuit (not so sure on the tube part-they don't teach how tubes work anymore. atleast not were i go to school) the costs and complexity would get pretty high pretty quick.

I don't know alot about circuits, but I wouldn't think it'd get too complex if you're just repeating the same basic thing over and over. Now it might get crowded and force creativity.

And as far as costs go, last I looked for them, transistors were dirt cheap.

[What5647]

yeah, but tubes aren't. and things are normally considered more complex when more parts are added, and yes it would be the same thing over and over. but you probably still see what i'm saying, the same effect can be accomplished with only a few stages, as opposed to spreading it out over 20 or so.

just as i typed this, i remembered something i worked on last semester that talked about how each type (kinda a class, but not like class a, a/b stuff) of amp has a maximum amount of distortion. i think this is what axguitar was thinking of, with each gain stage maxed, there would be a limit of how many preamps you could use. but again, if you're spreading all this out over 20 stages, it isn't an issue. i'll look that up tomorrow, and i'll post what i find, i know exactly were it was in the book.

[thesteve]

Originally Posted by What5647

yeah, but tubes aren't. and things are normally considered more complex when more parts are added, and yes it would be the same thing over and over. but you probably still see what i'm saying, the same effect can be accomplished with only a few stages, as opposed to spreading it out over 20 or so.

Oh...this is definitely true. The whole purpose of a "gain" knob is to control the amount of signal that's going to go through the clipping process. My idea is definitely looking at theoretical limits and ignoring practicality.

[What5647]

exactly.
heck, with the gain at zero, you could theoretically add thousands of stages.
i will look at some of this stuff in more detail tomorrow, there might be something on minimum gain for each class that i'm forgetting.
if there is, that would really blow our theories out of the water, huh?

[thesteve]

Originally Posted by What5647

exactly.
heck, with the gain at zero, you could theoretically add thousands of stages.
i will look at some of this stuff in more detail tomorrow, there might be something on minimum gain for each class that i'm forgetting.
if there is, that would really blow our theories out of the water, huh?

I realized there's an easier way to test the "11 stage limit" theory.

I wonder if it's feasible to run the effects send of a Peavey 5150 to the input of another 5150...then you'd have 12 gain stages hitting the power section...I think.

[nate95366]

From what I know about amps (which is more than the average layperson, and considerably less than say, Major Tom), there should not be a theoretical limit to the number of gain stages that could be placed in a theoretical amplifier.

Speaking practically, however, each stage:

1) Takes up space
2) Adds weight
3) Expands the potential for irritating noise (just think about what would happen if the first tube in even a 6 stage amp went even slightly microphonic).
4) At some point, can no longer effectively re-shape the sound as perceived by the human ear.

I would guess these practical considerations are why most amplifiers have a single-digit number of gain stages.

Nate

[What5647]

or you could also probably test it out with multiple boost pedals, all chain in a row.

[BillSPrestonEsq]

Originally Posted by thesteve

I realized there's an easier way to test the "11 stage limit" theory.

I wonder if it's feasible to run the effects send of a Peavey 5150 to the input of another 5150...then you'd have 12 gain stages hitting the power section...I think.

I have seen that done by a royal idiot with a pair of rockmaster's. I am not sure exactly how many that is, but my first guess would be 12.

Then again. Assuming my rockmaster's lead channel engages 3 12ax7's that would be six gain stages. There are 2 more 12ax7's in the classic 120 providing 4 more. Then there are the 4 power tubes providing at least 1 more, meaning that with no pedals, my rockmaster setup has 11 at the minimmum. Then don't forget that I have a 12db boost in the eq section, by the eq, and I am at at least 12.

[BillSPrestonEsq]

I consider high gain when the entire signal is distorted and you no longer get a portion of the signal unnaffected by the distortion.

[shreadhead]

Originally Posted by Rainer.

Hi-gain distortion: sound is always distorted, does not clean up when picked softly, and chords will not decay to clean if held for a few seconds
Over-the-top: more gain than typical hi-gain distortion

Ok then where does that leave my Fender Prosonics ( 6 12AX7's in the pre and dual cascading gain controlls for the crunch channel ) ? I consider them to have over the top UBER gain ( heck there is so much gain high quality CABLES are slightly microphonic with um ) BUT they respond VERY well to touch and tecnique. I can clean up well with just the guitar volume knob then roar back in with infinate sustain and feedback squeels. There is MUCH more preamp gain in these than in a 5150 yet they will still clean up with the volume knob.

[Rainer.]

No word definition is gonna perfectly describe tone. I also consider my Yamaha (also has 6 preamp tubes that deal with the amp preamp, one more deals with the reverb) to have definite over-the-top gain as well once the gain knob gets past 7 (I would also add that this particular gain stage is much fatter sounding than normal hi-gain). The tone of each hi gain amp/pedal will be different. My definitions deal with just the clipping and distortion structure of the output waveform.

[Forged by Fire]

This is high gain