A/B in one amp?

guitardevil2005 · #1 04-26-2006, 04:38 PM

whats up all, i havent been on here in a while because of alot of personal problems goin on ( particulary my g-pa haveing brain surgery and his recovery) so i wanted to drop by and see how everyones doing.

back to the topic:

i have a mesa boogie dual recto 3 chanel and in my current band i only use channels 1 and 3. i dont use channel 2, solo and the loop buttons(i dont use the FX loop at all in fact). i was wonderinf if it is possible to hook channels 1 and 3 threw the external channel switching in back to an A/B switch so i dont ave to worry about changing to un wanted channels or steping on un wanted buttons. do any of you have experiance with this or know if this is possible, i dont want to end up messing up my head over this so i would like to get some input from you guys first.

rgr · #2 04-26-2006, 06:42 PM

An A/B switch won't switch your channels for you. You need to contact Mesa about how to wire something like that.

guitardevil2005 · #3 04-26-2006, 07:55 PM

even if i go threw the external channel switching in the back, cause they made it seam like that was there to switch channels threw a i think its called a midi controller, or sumthing like that.

rgr · #4 04-26-2006, 08:09 PM

A MIDI jack will be a 5 pin DIN connector, and no, it won't work with a simple footswitch. If there is a 1/4" jack for switching channels you still need to know if it is 2 or 3 conductor, what contacts you need to switch to accomplish the desired result(s), if the switch is latching or momentary, and is there power on one of the lines for an LED. I think that about covers the possibilities.

Maybe the manual is online, I'll try to look at it later and see if I can give you some direction.

mesamaster · #5 04-26-2006, 08:31 PM

i thought the external switchings on the back of the recto was to control other devices?

am i wrong?

rgr · #6 04-26-2006, 09:32 PM

From the manual:

"EXTERNAL SWITCHING JACKS: These jacks allow ( usually MIDI-programmed ) operation of your amplifier’s functions from an
external switching source. In either case, the switching is accomplished by connecting ( “shorting” ) the jack’s “Tip” to its “Ring” (or
ground.)"

The "external switching source" would be a MIDI controlled switcher like a Roctron Patchmate, CAE switching system, or control jacks on some processors.

So, yes, you could wire a switch to switch between these, and you could probably do it with a PASSIVE A/B switch and 2 cables, but you will probably need to make a shorting plug to plug into the common jack so that it shorts one or the other jacks when it is switched. Make sense? The better way to do it would be to build your own footswitch and cable with a SPDT (single pole, double throw) switch and a cable with 3 conductors and 2 plugs on the amp end. Connect both of the barrels of the jacks to the common on the switch and each of the tips to one of the other poles. When you switch it will short one or the other of the control jacks. This way you don't have to worry about hooking it up wrong and possibly shorting both jacks accidentally which would confuse the head, shouldn't break it, but no guarantees.

Disclaimer, I don't own a Recto nor do I play one on TV, so I'm guessing from the online manual, the safest thing to do would be to contact Mesa for the final word.

Roger

toma · #7 04-29-2006, 12:07 PM

my amp has two inputs, do you gurs think itd be ok if i split my signal and ran one in to each input, haveing done seperate things to each signal??

a sort of poor mans two amp setup...

cheers

tx

rgr · #8 04-29-2006, 03:11 PM

Depends on the amp and how it "sees" the 2 inputs.

toma · #9 04-30-2006, 06:56 AM

it has the sami input gaion on both, but other than that, im not sure,
its a fender hot rod deluxe...??

tx

rgr · #10 04-30-2006, 05:31 PM

You may lose gain by using 2 inputs, but I"m just guessing, I don't have the schematic of that one. I'm not really sure what you would be buying by running it that way anyway, probably not worth the trouble IMHO.

toma · #11 04-30-2006, 05:39 PM

what should i look for in the schematic???

is there anyway that i could damage the amp by doing this??

cheers for ur info dude!!

tx

rgr · #12 05-01-2006, 11:50 AM

Just if it sums the 2 inputs into the first tube or if they have different paths.

Nah, shouldnt't hurt it, but again, I can't see any advantage to doing this over running your pedals in series into one amp.

toma · #13 05-01-2006, 12:38 PM

do i want them to have different pathss or not???

i want to use a particular setup of my rack fx as a single pedal, where as i cant turn them on/off remotely cos they dont have that facility, if i split the signal, then i can remotely turn themm on/off.

it works in my mind.....

tx

rgr · #14 05-01-2006, 03:17 PM

Checked it here, http://www.blueguitar.org/new/schem/...rod_deluxe.pdf, the inputs sum into the same path, yeah, it'll work, but I have no idea what you were trying to describe. Sounds like a pain to set up to me, but I went from a rack back to pedals and an amp.

toma · #15 05-01-2006, 04:19 PM

cheers dude!!!

yeah, it is a bit complex, but if it reduces the tone drain that is caused by these rack fx when not on then im up for it...

many thanks for the advice, i will now happily use both inputs, and if it goes wrong, blame you....lol. ony jokeing man, seriously, uve been really helpful!!!!

cheers!!

tx