Running both channels of a Twin Reverb simultaneously

[Lynxtrap]

alright, you all win. Going with two separate amps.

So...you bought another amp instead of trying the Twin with the split box..?
I mean, everybody needs a Twin and a Princeton, but after three pages of discussion it would be interesting to hear a witness account of how it works in practice.

 

[avspecialist]

Lynxtrap, Ill be your witness. I have done this with my 67 Super Reverb and it works perfect.

 

[D'tar]

But wait..... we're only on page 4!

 

[uriah1]

Barber Launch pad does this for Fenders.

 

[100LL]

I actually had the Princeton before the Twin. So I was always going to do the 2 amp setup. But for going out I was wondering if the twin could pull it off on its own.

 

[avspecialist]

The twin can do it, no problem. I like my 75 silver faced twin which I completely did over as ab763, but I changed the master control type to a PPI dual pot master. It really allows you to dial in the amp at any volume. I use it to play out and most of the times the master turns down to 3 gives a great low volume sound. But when my Led Zeppelin mode kicks in I can back off the master fully and with my SG it gets nice and loud and good sustain. Through in a few favorite pedals and you got it.

 

[Lynxtrap]

But for going out I was wondering if the twin could pull it off on its own.

Did you try it?

 

[Lynxtrap]

Lynxtrap, Ill be your witness. I have done this with my 67 Super Reverb and it works perfect.

I know it works
Just wondering if 100LL ever tried it to find out the answer himself after this somewhat confusing debate.

 

[elpico]

The key words here are "purely wet". It doesn't matter if the signals are mixed in the amp if the signals are not out of phase. A 100% wet reverb can't be out of phase (or in phase for that matter) with the dry signal. If that was the case, phase would be an issue in every amp with a built-in spring reverb. Have you ever heard of an amp where the reverb was out of phase?

Once the signal turns into a 100 % wet reverb, phase is no longer a factor.

I don't know if you saw it, but as I mentioned before, a fender amp can't produce a 100% wet reverb signal. When the signal comes back from the reverb tank it's always mixed with the dry signal before both continue on into the rest of the preamp. The mixing of the dry signal is accomplished with fixed resistors, there's no user control for it. The "reverb" control only adjusts how much reverb signal will be added to that fixed amount of dry.

Only higher mids and trebles are sent to the reverb circuit in the first place, so essentially all of the low end coming out of the "reverb amp" will be 100% dry signal, not wet, and it's the low end where you're going to get the most cancelation.

I've never claimed a 100% wet signal will cause phase problems, what I said was it's somewhat irrelevant since that's not something the amp can produce.

And I might as well say it again, none of this means you "can't do this". Of course you can do this. With either one amp or two, or heck, with five if you want. All I've been saying all along is phase does matter, and it will change when you engage certain pedals so you just have to be aware of that and plan accordingly.

If you're using two very different sized amps like this twin and princeton you may find that the contribution from the small one isn't enough to cause a lot of bass loss when they're out of phase, so that may be a point in favor of doing it with two amps instead of one, but it definitely can be done with the twin alone. You just need to pay attention to the overall phase of the two signal paths and then you won't have any cancellation at all.

 

[100LL]

Did you try it?

i haven't bought the ABY box yet. Im trying to do my research before spending money

 

[Lynxtrap]

I don't know if you saw it, but as I mentioned before, a fender amp can't produce a 100% wet reverb signal. When the signal comes back from the reverb tank it's always mixed with the dry signal before both continue on into the rest of the preamp.

Ok, misunderstanding. When we where talking about 100% wet I took for granted that the wet signal would go through some external effect device feeding the input of the second channel/amp.

All the easier to control the phase issue if it's all about using the built-in spring reverb.

 

[GeekyToneChaser]

Hey Tele-Mesiter, I just ran this experiment , and afterwards came to the internet to find tips and tricks. I found your post, and created an account just to respond with what I found in case it helps.

I have a Twin reissue and the radial ABY box you're asking about, and actually had been pursuing some tones this way.

My goal was to run wet/dry but only carry one amp. Hurdle is that phase issue. Here is how I approached it:

Guitar --> mono effects / fuzz /overdrive, etc. --> ABY

ABY set to "Y" with the switches set "up, down down" to reverse polarity and isolate output B, but not lift ground.

ABY Out A --> Wet effects (reverb) --> Normal channel 2, bright switch off.
ABY Out B --> 2nd overdrive stage (TS-808) --> Tremolo channel 2, bright switch on.

Obviously you could tweak this to taste, but I think the point is to feed in two sounds that are different, but are sounds you like, and sound like different guitars. And then blend to taste in the amp.

In practice the results are mixed. The core tone sounded outstanding with my Fender Jazzmaster. But some of the wet effects did not come through as well as they do with a "true' wet/dry setup.

My les pauls (PAF's and P90's) did not yield good results for me in this setup. Not at all. They just sound better going into one channel to my ears. The exception was that fuzz with the less paul, wet-dry into the amp this way sounded very good.

I repeated this with the normal / bright channels of a 4x10 bassman RI tweed with similar results. The jazzmaster did well, the pauls les so. Fuzz worked great. wet effects (verb, chorus, etc. were diminished).

The other bonus, was that I have a panning tremolo pedal, and if you run that in stereo to the two channels in this manner, it is panning between a wet sound, and a distorted, sound, as well as between a trebly sound vs. a bass sound, which is kind of like "harmonic tremolo" effect I've seen in boutique pedals. That was nifty.

That is what I found at least, for what its worth

 

[zombiwoof]

Hey Tele-Mesiter, I just ran this experiment , and afterwards came to the internet to find tips and tricks. I found your post, and created an account just to respond with what I found in case it helps.

I have a Twin reissue and the radial ABY box you're asking about, and actually had been pursuing some tones this way.

My goal was to run wet/dry but only carry one amp. Hurdle is that phase issue. Here is how I approached it:

Guitar --> mono effects / fuzz /overdrive, etc. --> ABY

ABY set to "Y" with the switches set "up, down down" to reverse polarity and isolate output B, but not lift ground.

ABY Out A --> Wet effects (reverb) --> Normal channel 2, bright switch off.
ABY Out B --> 2nd overdrive stage (TS-808) --> Tremolo channel 2, bright switch on.

Obviously you could tweak this to taste, but I think the point is to feed in two sounds that are different, but are sounds you like, and sound like different guitars. And then blend to taste in the amp.

In practice the results are mixed. The core tone sounded outstanding with my Fender Jazzmaster. But some of the wet effects did not come through as well as they do with a "true' wet/dry setup.

My les pauls (PAF's and P90's) did not yield good results for me in this setup. Not at all. They just sound better going into one channel to my ears. The exception was that fuzz with the less paul, wet-dry into the amp this way sounded very good.

I repeated this with the normal / bright channels of a 4x10 bassman RI tweed with similar results. The jazzmaster did well, the pauls les so. Fuzz worked great. wet effects (verb, chorus, etc. were diminished).

The other bonus, was that I have a panning tremolo pedal, and if you run that in stereo to the two channels in this manner, it is panning between a wet sound, and a distorted, sound, as well as between a trebly sound vs. a bass sound, which is kind of like "harmonic tremolo" effect I've seen in boutique pedals. That was nifty.

That is what I found at least, for what its worth

Did you try putting the LP's into the secondary inputs on the amp, that are slightly attenuated?. I know I often forget to try this, but some people always use that input for humbucker'd guitars. I don't know if that would help with a wet/dry setup, but it might be worth a try.
Al

 

[Euphonica]

Possible dumb question:

Can’t one rewire a regular guitar cable in reverse, making it a phase-switching cable?

 

[GeekyToneChaser]

Did you try putting the LP's into the secondary inputs on the amp, that are slightly attenuated?. I know I often forget to try this, but some people always use that input for humbucker'd guitars. I don't know if that would help with a wet/dry setup, but it might be worth a try.
Al

Good thought, and yes! I do use input 2 (cause of the way I use pedals this helps).

I think the reason the jazzmaster shined for me in this setup but the les pauls didn't has more to do with the EQ character of the original signal. With the JM they're kinda thin like single coils just in a wider box. Some JM's are like this. The clean input is pretty mid-scooped, and the "dirty" side (tube screamer) is more mid-boosted. That's why I picked the tube screamer for the application. Then they really stay out of each other's way and the amp can amplify both nicely without noticeable phase issues.

Maybe the helpful piece for the OP is the that I got one great result out of many experiments, so it can be done... perhaps there is even be some method to the madness that will help you on the journey!

 

[arnieus]

Just use two Twins like I do.
View attachment 758050

Looks awesome. I don't mind making two trips to a gig.

 

[ToolmanTim]

Old thread, but I second the poster about using a Barber Launch Pad. He designed the pedal as a clean boost, and, to correct the phase issue in BF amps. I use it and dial a mix from both the normal and vibrato sides of my Fender DRRI and Fender TRRI to taste. Good deal.