Parallel cascaded gain stages

[villll]

Hiya!
I've been reading about different types of gain stages and immediately after having read about cascaded and parallel gain stages I thought about a design consisting of two cascaded stages parallel with two cascaded stages. Has this been done before or is there even any practical use for this? Or have I got the whole thing all wrong?

[J M Fahey]

It has been done before.
80's Peaveys, Randalls, and some Laneys had a single input jack connected to two channels (each of which is made of cascaded gain stages) and the primitive channel switching they used could short to ground the output of either of them, leaving the other one "on".
By unplugging the footswitch pedal, or by design, adding an extra switch, you could ground none, so both did sound at the same time, and were combined, as you imagine it , in parallel.
Peavey even went beyond that and offered the possibilities of running both channels in *series*, for monster gain and distortion.
I think that feature was called "automix" or somethinhg like that.

[villll]

Thanks for your post!
Alright I'll see if I can find some schematics. I might try building my one idk. Was thinking i'd make the two parallel stages dissimilar, one cleaner than the other, and use a pot to blend them together.

[joecool85]

Thanks for your post!
Alright I'll see if I can find some schematics. I might try building my one idk. Was thinking i'd make the two parallel stages dissimilar, one cleaner than the other, and use a pot to blend them together.

Could be interesting.  If you do decide to go with it, keep us posted as I'm sure we'd all love to see/hear it.

[KMG]

Thanks for your post!
Alright I'll see if I can find some schematics. I might try building my one idk. Was thinking i'd make the two parallel stages dissimilar, one cleaner than the other, and use a pot to blend them together.

Examples of paralleling different stages
Legendary amps
Hiwatt DR103
http://milas.spb.ru/~kmg/files/schematics/hiwatt/DR103/DR103_preamplifier.pdf
Marshall SLP
http://milas.spb.ru/~kmg/files/schematics/marshall/1959SLP/1959SLP1.gif