#1
I've more than once seen patched inputs on plexi style amps, or multiple input ones in general.

The guitar straight into a certain input, and then a cable running from say input two, to say input three.

What's that?
What does that do?
Am I mistaking something?
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#2
AFAIK, in Plexi style amps it adds gain because the signal paths are somewhat separated, and plugging into the input of both engages both paths at once.

In newer amps, plugging into both doesn't do anything, it just runs as the "high" input. It doesn't add the "Low" and the "High" together like an old school amp would.

I'm sure someone else can explain that better.
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#3
If you look at a schematic of a plexi, you'll see that each input column goes to one half of a 12AX7. You'll also see that the inputs on each column are tied together.

So when you use a patch cable, you're basically splitting the signal and sending it to both halves of the 12AX7 instead of just one. This ups the gain a bit and just generally changes the character of the amp.

Usually it's called "bridging the channels" or "jumping" or some permutation thereof. Incidentally, the reason you don't see this on older Fender amps is that their preamp channels are out of phase and would sound funny bridged.
#4
Quote by Spambot_2
I've more than once seen patched inputs on plexi style amps, or multiple input ones in general.

The guitar straight into a certain input, and then a cable running from say input two, to say input three.

What's that?
What does that do?
Am I mistaking something?


on my JTM45 clone it allows me to use both channels at once, i can balance the normal and bright channels using their respective volume knobs.

as mentioned earlier you can also get more gain. colin's post has the technical answer it seems.
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#5
I do it on my JTM45 too. One is a bright input and the other is a normal one. With the inputs bridged I can balance out the two (they have separate volume controls) until I get the tone I want - just like gumbi.

On a somewhat related note. The classic 18W Marshall has two inputs (high and low) where the high input effectively is both inputs bridged. It gives a thicker sound. Same idea as bridging the inputs with a jumper but it's done internally by a switch on the jack.
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