Dual Rec Channel Problems

Just bought a used dual rec three channel amp. worked great when i tried it out, got it home, hooked it up and the channel lights / foot switch no longer work. there is no output at all, cannot switch channels or anything. guessing it's headed straight to third coast for service, but was wondering if anybody might know what would cause this. is there something that i can do without a pricey service shop visit? has anyone else had this problem?

it powers up fine, the tubes all look good (though i'm not sure they would have anything to do with channel switching). i've done about everything i can possibly think of to remedy the problem short of taking the amp apart.

thank you in advance for any help or suggestions....

cory :?:

Well, keeping it to the basics, did you check the pins on your cable? Have you tried a different cable? Do you have a 1/4 jack footswitch laying around you can try on the external switching inputs? I would start there.

i cannot even get the channel lights to show me what channel is selected without the foot switch. there is just not any output at all.....

Wow, that does sound wrong. Mine starts up on channel 2, but I never tried it with the footswitch unplugged to see what happens. My footswitch is always plugged in. Hmm, I may have to go home and unplug the footswitch then turn on the amp and see what happens.

keep me posted, and thank you for the help

In the meantime, I would unlpug the cable and really inspect it on both ends. I don't recall if the cable has specific ends or not, but if they are the same, look at both of them and then swap them and plug the end that used to be in the footswitch into the amp and vice versa. Assuming you can do this. I don't remember if the cable ends are the same. Maybe you have a bent pin. Because you said that when you tried it out and it worked, but then when you got it home it doesn't leads me to believe its the cable more than anything.

i'll look into that, the lack of output and switching at the head have me more concerned than just the foot switch though

Well you might have a preamp tube problem. I just unplugged my cable to the footswitch and it still stayed on channel 2, so that is ruled out. Try swapping around some preamp tubes.

Wow! This sounds eerily similar. Yroc what year is your Dual Rec? Mine is a 2002. What brand of tubes are in it and what config? (34's, 6L6's, straight 12AX7's or any LPS's or AT7's? Were you attempting to use the external switching jacks? What you're describing is almost a mirror replica of my 3 channel Dual Rec problem. Personally, and this is just pure speculation at this point, my feelings are that the external switching jacks are a serious weakness of this amplifier. The last time I spoke with Mesa about it I asked if they would ever incorporate MIDI switching into their amps and they promptly said "No, that there were no plans to". Believe me to have an entire rig-channel switching,effects switching,loop switching,external device switching, etc all controlled by MIDI without having to go the separate preamp/power amp route (been there-done that) and without having to go third party (Access- another 200 or so dollars) is an awful convienent and IMO necessary feature.Especially is this age of integration. Ya know..puters and stuff! :roll:

i was messing with the loop jack on the back, but nothing was working with that, so i just unplugged the cables and nothing has worked since. i'll have to take a look at the tubes to see what they are, but i'm pretty sure they are the original ones that shipped with it. this is my first multichannel tube amp. i've always used single channel amps (because i didn't have to sell body parts and plasma to afford them). I've always wanted a mesa but this is really turning me off to them. it seems like this should just work, barring a a drop form 10 feet or so. would a blown tube effect channel switching? i could see there not being any output with a bad tube, but for the channel lights on the head to not even work? i would think an entirely different set of electronics controlled that stuff. my ignorance on the topic is probably showing here, so i'm sorry if i come off as a noob. it would be really nice if this were something i could remedy myself without having to take it to a shop and drop hundreds more into it. at this point, i would be happy if just one channel worked....

Refer to page 25 of your owners manual.

i assume that is the Diagnosing Pre-Amp Tube Problems. The part about the Tube Driver sounds kind of like whats going on, but i'm not getting any of the crackling or squealing that would indicate the pre-amp tubes. i wish i had any noise at all coming out of it right now, it's just dead quiet. would those tubes drive the channel selection as well?

You need to look at your preamp tubes, look at the schematic in the back of the manual and it describes what each preamp tube does.

will do, really appreciate all of the help!!!

i went out and bought some new tubes this weekend, so i'm gonna start swapping pre amp tubes. i also noticed that one of the power tubes was glowing a little blue. could that mean a filter cap is bad?

Unplug the footswitch and try to switch the channels using the knob on the back of the amp. If that works, it is the footswitch or cable.

i did that, it was a no go

well, it's headed to the shop for repair. i cannot figure out what's going on. thank you to everyone that offered help...

Hi, just wondering what ever came of your amp, mine did the same thing, how did they fix it, was it costly thanks garry