PBC & Dual amps/Dual stereo fx loops

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Thought a few might be interested in this routing option. These are not my amps I use but the routing should work on most dual amp setups with serial fx loops. Of course there is also channel switching that can be done and also another stereo fx if needed.
 

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Thought a few might be interested in this routing option. These are not my amps I use but the routing should work on most dual amp setups with serial fx loops. Of course there is also channel switching that can be done and also another stereo fx if needed.

Thanks very much for this, gives me lots to think about! However, I want to accomplish something slightly different. What if I want effects in 1-4 running to the inputs of BOTH amps and all stereo effects in 7-10 running to the effect loops of both amps?
 
Thanks very much for this, gives me lots to think about! However, I want to accomplish something slightly different. What if I want effects in 1-4 running to the inputs of BOTH amps and all stereo effects in 7-10 running to the effect loops of both amps?

You'll need a Y cable or splitter to split the output of loop 4 to the inputs of both amps. You can also use Out 5-6 as an output for the second amp if you aren't using loops 5 or 6.

As for loops 7-10, all of the pedals in these loops must have stereo inputs and stereo outputs. Then, you combine the loop sends of both amps together using an insert cable, which connects to In 7-10. The "Mono -> Stereo (out)" button should be pressed in. Each pedal must be connected to the PBC with insert cables. Then, the A and B outputs are connected to the loop return of each amp. The Mono Output button should be in the "out" position. If you get hum, you'll need to add more isolation transformers to the system. If you're lucky, you'll only need the one on the B output of the PBC, which you can turn on with the Iso B switch.
 
Thanks very much for the prompt and precise reply...I appreciate it. I've been researching for a week and the good news is it seems your product is the only one that will accomplish what I want! So if nothing in 5-6, I can use out 1-4 to Amp1 input, out 5-6 to Amp2 input? Otherwise a Y or splitter for out 1-4... Straightforward enough.

Pedals on loops 7-10: I'll need stereo in/out... understood.

Thanks again, will be trying to track down a unit through your Canadian dealer asap.

Cheers.
 
Hello, received my Mastermind PBC today... trying to get everything wired up in stereo and not having much luck. In an effort to troubleshoot I disconnected EVERYTHING from the PBC except the guitar input and connected Out 1-4 to the input of AMP1 and Out 5-6 to the input of AMP2. As soon as the cable is plugged into Out 1-4, any signal to Out 5-6 is muted. If I remove the cable from Out1-4 signal to Out5-6 returns. I'm sure this is something stupid that I'm missing, could someone help?
 
Hello, received my Mastermind PBC today... trying to get everything wired up in stereo and not having much luck. In an effort to troubleshoot I disconnected EVERYTHING from the PBC except the guitar input and connected Out 1-4 to the input of AMP1 and Out 5-6 to the input of AMP2. As soon as the cable is plugged into Out 1-4, any signal to Out 5-6 is muted. If I remove the cable from Out1-4 signal to Out5-6 returns. I'm sure this is something stupid that I'm missing, could someone help?

Derek, you'll need an Y-split cable from Out1-4 or Out 5-6 to connect to both amps. You don't get one signal out to one amp from Out1-4 and the other from Out5-6 at the same time without feeding a signal to IN5-6.
Once you put a cable in Out1-4, the PBC cuts the signal to all further loops for outside processing and expects you to put a signal back to IN5-6, which will then go through loops 5&6 before getting to Out5-6. Here's the same procedure: if you don't put a cable in Out5-6, the signal goes straight to IN7-10. If on the other hand you put a cable in Out5-6 the PBC will cut the signal and expect you to put it back to IN7-10.

However, when I understand correctly what you want to accomplish, you'll need a different setup.
If you want Loops 1-4 before both amps and stereo loops only feeding from the fx loop of Amp A and also all the stereo effects on both amps you won't need an Y-cable, assuming that both of your Amps fx send/returns are serial. The preamp signal of Amp B will be cut when you put a cable in its fx return, so feeding Amp Bs input will give you no hearable signal.
Once you take the FX send from Amp A, that is the signal the PBC sends into the stereo effects. You can only use the preamp of the same Amp you use the fx send signal from.


Here's the signal chain:

Out 1-4 -> Input Amp A

FX loop Amp A send -> IN5-6

Output A -> fx loop Amp A return
Output B -> fx loop Amp B return or Input Amp B

Thats pretty much the same setup as the one on page 20 in the manual. Just with fewer loops.
 
Ok thanks very much for taking the time to explain Ralf. I understand why Out5-6 was not producing sound now... but my original intention was to have 1-4 send to both preamps and then send anything after that to the effect loops of both amps. I guess I could just use the Y splitter on Out1-4 as was original suggested..

So the signal chain would be:

Out 1-4 -> Input Amp A, Input Amp B (using mono Y splitter)

FX loop Amp A & Amp B send -> In 7-10 (using insert)

Output A -> fx loop Amp A return
Output B -> fx loop Amp B return

(I don't have anything connected to Loops 5-6)

Does that make sense?

However, after going through all of this I'm finding that I'm actually not entirely sure if I want to use the effect loops after all... it seems to be affecting my tone. Also, I'm so used to running my modulation pedals before the preamp that I might just use the Output A&B to both Amp inputs and forget the effect loops. It's a little noisier running modulation before a preamp but I guess whatever works...

I like that I have the flexibility to do both, I'll have to experiment some more with both options before finalizing anything on a pedal board. (My floor is a giant spaghetti mess of cables at the moment... lol)

Loving this PBC!

Thanks.
 
+1 on the floorghetties, I'll get my new patch cables next week and hopefully the mess will have an end :D

Thanks for clarifying your idea. Is there a particular reason for you to want the sound of both preamps feeding your stereo effects?

Doing a lot of audio engineering work, I presume you will run into all kinds of phase issues even when both amps are matched. It might work with true stereo processing pedals that process each input individually, but other than some hard-panned LR-delays I can’t think of any algorithms that won’t mix the input signals. Every reverb or modulation pedal will mix the input channels in some way resulting in interferences from the different input signals. Using only one’s amp preamp will most likely give you the best result with stereo pedals since you have eliminated all potential phase issues.

I totally get your hesitation about using the effect loops. I’ve run into some amps that didn't have an optimized level adaptation and it was just a mess. You can test your amps loop by bridging it with a cable and try to get the levels right. There are also line-mixers that can adjust the levels of the fx loop. A good amp modder can be of value as well in that regard. If you want to utilize your amps channels though it seems to me that there is no other way than going with the fx loop.
Of course there are those players that make all their distorted sounds with dirt pedals and run into the input of a well sounding amp - it's a matter of ones philosophy.

Anyway, after pondering your idea I was thinking that utilizing the preamp section of both amps could work when the preamps are used alternately. One would need a switchable A/B/Y-Box, that is fed by both amps fx send and could also be remotely controlled. I’m not sure if the rjm Y-Not A/B/Y switch can do this - seems to me the signal path is the other way around. I have a Little Lehle that does that but it’s not controllable via midi.

The signal flow would be like

PBC Out1-4 -> Input Amp A, Input Amp B (using a Y-splitter)
FX send Amp A -> Y-Box In A
FX send Amp B -> Y Box In B

Y-Box Out (selects either A or B) -> PBC In7-10

Ok, I ramble like a little girl…but that sounds really interesting to me, the possibilities seem promising.
I'll have to take a further look into that idea.

Thanks!

PS: Anyone aware of a midi controllable A/B->Y box?
 
Hey Ralf,

The only reason I wanted both preamps was I am just loving the blended tone of these two amps together for my crunch sound (Mesa + Marshall). In fact I don't think I could live without this blend now... it rounds my tone out so nicely :) However, perhaps I don't need even need to do this... Could you perhaps clarify something for me? Am I going to hear a significant difference in tone by using the preamp of a single amp or are the power tubes more responsible for the tone? Clearly, having EL34 tubes in one amp and 6L6 in the other should certainly have an effect on tone... but I'm not sure how much the preamp is responsible for tone as well.

I appreciate all your input here... I'm doing so much experimenting sometimes I think I'm getting in over my head.

(In fact I just went a step further and started using a Micro POG with the dry output going to guitar and wet going to a bass amp ... so a single guitar is playing through two amps in stereo as well as a bass amp for lower registers! Not sure if I want to stay on this route or not, it gets a little crazy but it's an interesting experiment. Having the Mastermind PBC makes it so much easier to experiment as well, this unit is amazing. I can switch the POG on/off to kill the bass or mute my guitar outputs to have bass only. I've already set presets to do this...The fun is just beginning. Haha! )

And go ahead and ramble away my friend, I love to hear input and ideas... long gone are the days I plugged my Les Paul right into my amp and thought that's all I needed. :)
 
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I like the bass amp idea and will definitively try that !!

I’m also in over my head, but that’s why we've bought a pbc and not a boss looper ;-)

You’re right, blending two amps can make you feel great on stage! You should try the Y-cable, maybe you don’t have any interferences at all. Maybe you’ll lose some punch in the bass which is most likely an indication of a phase issue. You’ll never know before you’ve tried.

When I get to this idea from a recording perspective, I would prefer mixing both amps into one signal before processing it with effects - that’s how it's usually done. Two signals from two different amps almost always need some sort of treatment with their phase, so I personally would not prefer that in a live situation. But give it a try and let me know what your soundguy has to say :D

As far as influence on the tone goes, I’d say - from a recording perspective - power tubes are way overrated (I see stones coming my way…). And I’m not talking about heads like the Z Wreck or similar amps that are built to create a significant amount of crunchiness and compression by hitting the power tubes hard. On a typical combo amp or head with 2-3 channels, drive and tone control, I’d say the the power tubes are maybe 5% of the technical side of the tone in most cases. Preamp, cabinet, good cables, microphone, mic-preamp and a good match between guitar, pedals and amp are from a technical perspective way more hearable IMHO.
But of course, there is this one clean tone that gets the perfect amount of sparkle once the power tubes hit the right spot that you don’t get otherwise and is sooo inspiring :)

Keep on digging !!
 
Derek,
For the outputs to the front of your two amps, use an iso splitter which has a phase flip switch on one of the outputs. This should deal with any phase and/or audio ground hum issues.
 
Sorry to revive an old thread. This diagram is really helpful and I'd ideally like to be able to run something similar to this and had some silly questions.

I'm looking to purchase a PBC10 to control my pedal board and two amps, with the option to turn one of the amps on/off in sections (the band has one guitar, so it's to replicate 'dual' parts on recording where one guitar will drop in or out).

Both amps will be dirty and an FX loop running to each will be critical (verb, tape echo, noise gate if needed etc).

Is this doable without the additional Y-not box (I noticed they're no longer available)? Would the isolated B loop from the PBC10 not take care of ground hum itself?

I've not used anything like a midi/pedal switcher for many years, so please excuse my ignorance. It's difficult to get my head around how it will function and whether it will actually do what I want without owning one yet.

I'm also intending to run some fx like the Gamechanger Plus/EHX freeze but unsure whether I need to place these in a loop or at the end of chain (I'm assuming end of chain before preamp and not in a loop is the correct answer to this as they're a momentary type effect and i'd want to control them discretely).
 
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Using two amps with effect loops is the thing that makes it a bit complicated. If you want both amps to retain their own "identities", all of your effects in loops 7-10 need to have stereo input and stereo output, so that the stereo signal is maintained throughout. If you do that, then it's not too bad. The effect loop sends combine with an insert cable and go into In 7-10, and Out A and Out B go to the effect loop returns.
 
Hello all... I see this is an older thread but the closest in my search results to what I'm trying to accomplish... Any help would be highly appreciated.

I would like to be able to run and switch between two heads (independently) with the PBC 10, one for dirty, one for clean. Currently I use one dual channel head and the PBC operates seamlessly with all the settings I have it programmed for to switch between clean and dirty and have all my desired pedals doing their thing on each channel. No issues, love the PBC for this.

However, I recently added a high gain single channel head to my gear collection and am wondering if I can still use the PBC to seamlessly accomplish between dirty and clean on two separate single channel heads rather than one dual channel one.

And, if there is no set up in which the PBC itself can switch between both independently, ideally what would be easiest to way accomplish this and still use my PBC for it's other intended operation of multiple pre-sets of pedals etc? Amp Gizmo? Standard old fashioned ABY? I'm trying to avoid all the tap dancing which is the whole reason I have a PBC in the first place, but would love to run two heads independently for dirty and clean tones.
 
Hello all... I see this is an older thread but the closest in my search results to what I'm trying to accomplish... Any help would be highly appreciated.

I would like to be able to run and switch between two heads (independently) with the PBC 10, one for dirty, one for clean. Currently I use one dual channel head and the PBC operates seamlessly with all the settings I have it programmed for to switch between clean and dirty and have all my desired pedals doing their thing on each channel. No issues, love the PBC for this.

However, I recently added a high gain single channel head to my gear collection and am wondering if I can still use the PBC to seamlessly accomplish between dirty and clean on two separate single channel heads rather than one dual channel one.

And, if there is no set up in which the PBC itself can switch between both independently, ideally what would be easiest to way accomplish this and still use my PBC for it's other intended operation of multiple pre-sets of pedals etc? Amp Gizmo? Standard old fashioned ABY? I'm trying to avoid all the tap dancing which is the whole reason I have a PBC in the first place, but would love to run two heads independently for dirty and clean tones.
Do these amps have effect loops, and if so, are you using them?
 
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