Channel Switcher thing

[talking_goat]

I've got a 2:90 poweramp and I want to use all three of it's features (the deep, modern and 1/2 drive) but you need a channel switcher for each input (if that makes sense). I was just going to try and knock one up myself but am not sure what I'll need or 100% sure how to do it.
Can i use patch cables and cut the end off and wire them to a switch, and what sort of switch. See questions, too many questions.

[Im using a JMP1, not a triaxis so I can switch it using that.]

[talking_goat]

bump

[talking_goat]

The original post didn't make much sense did it?

[petemoore]

I'm not exactly sure...
 Three channels...hmmm
 Could be a couple 'short to ground' switches.
 IIUC, there's jacks on the amp [never heard of a 2:90] that channel switch...
 If it's not digital, it could be a short to ground setup...you have 1 ground wire and 2 [?] other wires...short one to ground [channel 'A'] short two to ground [channel 'B'] leave both open [channel 'C']..or some such arrangement...
 I've never heard of someone causing damage by shorting the tip to sleeeve [etc] when trying to find the remote channel switch function...YMMV...
 Without knowing what's up with the amp, I'd try shorting the channel switching jack[?s]...say a tip to sleeve for starters...you might want to wait till after ascertain the correct wiring. Maybe look for a schemtic first or something.
 I'ts a common way to do switching, I've seen this sorting method used before, and haven't heard any "I fried my ...." stories [yet]...
 My marshall with Ch switching had a Tip Ring Sleeve [switch for reverb I/0 and channel A/B] arrangement, tip to sleeve=reverb, ring to sleeve=Overdrive ch.
 Anyway I figured out how they work by just trying different shorts to ground from the channel switching stereo phono jack on that amp.

[talking_goat]

It's not a digital amp. It's the Mesa Boogie simul 2:90 poweramp.

[niftydog]

but the switching circuit might be digitaly controlled, I think that's what he was getting at.

Commonly you just need to ground the switch control lines to affect a change.

Do you have a manual or any more information about the amp?

[lovekraft0]

It's been a while since I've seen a 2:90, but unless I'm mistaken, both the Deep and Modern jacks are just short to ground switching circuits. Check the schematics here to verify that.

[talking_goat]

but the switching circuit might be digitaly controlled, I think that's what he was getting at.

Commonly you just need to ground the switch control lines to affect a change.

Do you have a manual or any more information about the amp?

The manual is actually one of the funniest things I've seen, for such a pricey product it is probably the most piss weak manual I've seen. Looks like monkeys have knocked it out on a type writer!

How do you ground the switch control lines?

[niftydog]

the sleeve terminal will be ground. Simply connect the tip or ring terminal to the sleeve terminal to ground it.

[markr04]

Hi talking_goat. I was gonna build my own also (mine is less complex than yours though). But it turned out to be much cheaper to buy one from musiciansfriend.com. Maybe this will suit your needs, maybe not.

http://www.musiciansfriend.com/srs7/g=guitar/search/detail/base_pid/158006/

[william]

A latching switch will work.  you can get a two button amp switch with the tip-ring-sleeve jack, split that into two 1/4" jacks, and then plug that into the back of the 2:90.  I don't see why you'd want to switch the 1/2 drive switch live but the other two make sense.  The schematic for the switching section of the amp follows.

[talking_goat]

Would I be able to rig something up using standard instrument cables? Like cut one in half and rewire the jack or something?

[niftydog]

standard instrument cables do NOT have TRS plugs. Using one will effectively permanantly short out the ring to the sleeve making switching impossible.

Besides, an instument cable is worth more than the sum of it's parts.

Buying a cheap TRS plug and some cheap cable will work out better I would imagine!

[Satch12879]

The manual is actually one of the funniest things I've seen, for such a pricey product it is probably the most piss weak manual I've seen. Looks like monkeys have knocked it out on a type writer!

What did you expect a telephone book? The manual tells you exactly what you need to know and that's it.  Jeez, the 2:90's only two volume and presence knobs, power and standby switches, and all the jacks on the rear.  Plug source in, plug speaker out, turn on, warm up, play loud.  It's not that complicated.

[talking_goat]

The manual is actually one of the funniest things I've seen, for such a pricey product it is probably the most piss weak manual I've seen. Looks like monkeys have knocked it out on a type writer!

What did you expect a telephone book? The manual tells you exactly what you need to know and that's it.  Jeez, the 2:90's only two volume and presence knobs, power and standby switches, and all the jacks on the rear.  Plug source in, plug speaker out, turn on, warm up, play loud.  It's not that complicated.

Your right it's not complicated, but that's not really what I was getting at. I just suppose I expected it to look a little more professional seeing as the unit costs so much. I dunno, I thought they may have moved on from type writers or something.

[talking_goat]

Are TRS plugs also called something else??

[talking_goat]

I picked up a couple of mono jack and wire the tip to ground as suggested and everything works (I leave them on all the time so I didn't need a switch). I have to say, this is by far my most successful project to date!!!!!

[niftydog]

Are TRS plugs also called something else??

hmmm, deja vu.

stereo jacks.