Paralleling input channels is nothing uncommon and can have great results.

So you just run a Y-cable from your guitar to the 2 inputs on the amp? I have owned a Twin for years and never even thought to try it. Sounds interesting. I'm going to try it tonight at rehearsal!

firstly, this is off the top of my head, and i have not thot about audio electx for at least 2mos

>>Let's assume and 8Ω output impedence of the first amplifiers speaker out and a 1MΩ input resistor in the second amplifier. If connected in the way of the original post, these resistances (impedences) would be in parallel which would give you a resistance total just under 8Ω. Therefore, the change in load, as far as the first amplifier is concerned is nominal.

but you have to load the tube amp appropriately. the preamp input impedance is way too high.

it might work for a while, but eventually....

ever been playing thru a tube head at high volume and had the speaker lead come out? it will blow something up in the head.

in this case:

pluggin' the speaker outs into the preamp input the speaker means replacing the speaker impedance w/the input impedance of the preamp, which is very high relatively speaking.

is much like having the feeder head unloaded, b/c the preamp input impedance is so high. it's real bad for the feeder head unless you modify it so it's already loaded properly w/o a speaker.

the eater head, probably no big deal, as long as eater amp has reasonably rated input resistor and feeder is tube amp (like russ sez, i think SS would dump mass current into eater head and kill it--the output transformer in tube amps protect against this)

the reason the combo sounds the way it does:

1. you are overloading the input stage of the eater head something fierce.

2. you are providing the feeder head w/a load that is largely resistive, which will not be damped w/respect to frequency. therefore it sounds different, and it also makes demands on the feeder amp that are not made by a speaker, which is a reactive load.

3. the output stage of the feeder head is operating at a higher voltage, as it is dumping less current than it is supposed to dump.

I think I might try an input channel parallel with my twin... Russ, would you be able to tell me how to set it up without frying anything? Also, does this cause any additional wear and tear?

thanks,
george

as far as how to get a similar (though not identical) sound with a pedal, i would think that just about any distortion pedal would do the trick, if you turned the distortion knob all the way up and turned the output knob all the way up. that should get you an absurdly loud and overly distorted sound. if the amp has a master volume, you could also crank the input volume/gain knob and keep the master low enough that you aren't going deaf.

shit, you can also just run your signal through two distortion pedals and crank all the knobs on both of them. that'll get you a pretty disgusting sound, too.

i can already picture the nonstop screeching wail of the amp when you're not playing anything.

marco wrote:So you just run a Y-cable from your guitar to the 2 inputs on the amp? I have owned a Twin for years and never even thought to try it. Sounds interesting. I'm going to try it tonight at rehearsal!

i feel stupidly confused about this, but is that different than cabling two input channels together... i.e. running into input 1 in channel 1, then out of input 2 of channel into input 1 of channel 2.... is that what you meant, IdDrummer?

gio wrote:

marco wrote:So you just run a Y-cable from your guitar to the 2 inputs on the amp? I have owned a Twin for years and never even thought to try it. Sounds interesting. I'm going to try it tonight at rehearsal!

i feel stupidly confused about this, but is that different than cabling two input channels together... i.e. running into input 1 in channel 1, then out of input 2 of channel into input 1 of channel 2.... is that what you meant, IdDrummer?

That's it exactly. The thing I liked about that sound and that of the two-amp embroglio was that when not playing the guitar, there is relatively little sound coming out of the speakers.

idiot drummer wrote:That's it exactly. The thing I liked about that sound and that of the two-amp embroglio was that when not playing the guitar, there is relatively little sound coming out of the speakers.

Hmmm... i'll give it a go.

It makes sense as an innovation, since the 60s twins don't have gain pots before the power amp... I'm guessing this is a rig that allows you to tweak pre- (channel 1) and post- (channel 2) gain.

So the question is: will it sound better than my fulltone OD pedal? we shall see!

idiot drummer wrote:

gio wrote:

idiot drummer wrote:I was thinking back to an old bandmate who would plug channel one of his Twin into channel two. I understand that these are parallel circuits (right?), whereas this other amp combination is not.

You mean he would run a line from the speaker out of the twin back into channel 2?

No, it was some crazy thing where he would run a cable from the input of channel one into the input of channel two. The higher the decibels, the more overdriven the tone. I've heard of this since, but never tried it, as I do not own a Twin.

I think you can do this on many Fenders, Ampegs, etc.- any two channel amp that has normal and bright input jacks for each channel.

Plug gtr into normal input channel one, and then use a short quarter to quarter cable from the bright input of channel one back into the normal ( or bright ) input of channel two.

I believe the advantage is that each channel has dedicated preamp tubes, and some are idle if only one channel has input. Doing the above means that all preamp tubes are feeding the power amp.

I'm sure someone will correct this if it's wrong. I know a guitar player who does this with an Ampeg V-22, and it breaks up much earlier.

toomanyhelicopters wrote:as far as how to get a similar (though not identical) sound with a pedal, i would think that just about any distortion pedal would do the trick, if you turned the distortion knob all the way up and turned the output knob all the way up. that should get you an absurdly loud and overly distorted sound. if the amp has a master volume, you could also crank the input volume/gain knob and keep the master low enough that you aren't going deaf.

shit, you can also just run your signal through two distortion pedals and crank all the knobs on both of them. that'll get you a pretty disgusting sound, too.

i can already picture the nonstop screeching wail of the amp when you're not playing anything.

The problem w/ this approach, and why it differs from the one discussed, is that most guitar distortion pedals use diodes to clip the signal. The distortion produced is distinctly different than that produced by an overdriven tube amp.

Oh, that is, unless you're using an Ibanez TubeScreamer.