Dual Rectifier Blackface cutting out

[SolDropplyr]

Hey Everyone,

I just bought a Dual Rectifier Blackface (SN: R-0013XX) off of CL the other day. I was dialing in tones last night when I started getting intermittent power problems. All the LED's (including the footswitch, bias switching on the back and channel switching) with the exception of the "jewel light" next to the stand-by switch stopped working and there was no output. I checked the fuse and it was fine. I would put it in stand-by for a minute and switch it back on and it would come back on.
So I began troubleshooting it to see if I could figure it out, but before I could the amp completely shut down and all that will light up now is the jewel light with no output or any other LED's.

Here’s how far I got with my troubleshooting:
I ran it through a power conditioner
I ran it directly plugged in the wall
I ran it only on the clean setting
I ran it only on variable high gain setting
I ran it only on the vintage setting
I ran it only on the modern setting
I ran the vacuum tubes setting
I ran the silicon diode setting
I ran it on the bold
I ran it on the spongy
I ran it without the footswitch (manually switched between the channels)
Loop bypassed, guitar plugged directly in
8OHM output to 8OHM 4X12 cab

After every change it would cut out more frequently each time. I knew that the amp needed to be re-tube, but I thought I would get more enjoyment than an hour and a half before I had to do anything to it.

Any thoughts?

 

[lerxst88]

are the tubes staying lit as well? Also are the tubes matched to the Bias switch?

If the fuse isnt blowing you may have bigger problems than just tubes. I might guess the choke is no good?

If anyone else wants to step in Im very curious about this problem too.

 

[SolDropplyr]

Yes tubes are all staying lit and bias switching is set to 6L6 (which is the correct power tubes).

Also, when I got it I put it through a pretty thorough cleaning, pulled each tube (one by one) and sprayed contact spray on all connecting points and re-installed them. I did notice that the tension on one of the sockets in the power section and recto section was kinda loose. I know this is an older amp, so I didn't really give it any attention. Do you think this may have something to do with it? (fingers-crossed)

I took it in today to my "friendly neighborhood amp tech" to diagnose the problem. Hopefully not, but if it is the choke I will find out soon enough... I thought I could dodge that bullet for at least a little while.

Quick question on choke problems - Do they show up immediately or is it intermittent then the amp dies. Like I said before I have probably logged an hour and a half on this amp so far. I'm just trying to determine if the previous owner knew about the problem prior to selling it.

 

[Anonymous]

Yes tubes are all staying lit and bias switching is set to 6L6 (which is the correct power tubes).

Also, when I got it I put it through a pretty thorough cleaning, pulled each tube (one by one) and sprayed contact spray on all connecting points and re-installed them. I did notice that the tension on one of the sockets in the power section and recto section was kinda loose. I know this is an older amp, so I didn't really give it any attention. Do you think this may have something to do with it? (fingers-crossed)

I took it in today to my "friendly neighborhood amp tech" to diagnose the problem. Hopefully not, but if it is the choke I will find out soon enough... I thought I could dodge that bullet for at least a little while.

Quick question on choke problems - Do they show up immediately or is it intermittent then the amp dies. Like I said before I have probably logged an hour and a half on this amp so far. I'm just trying to determine if the previous owner knew about the problem prior to selling it.

It's probably a preamp tube. Are you running a Sovtek LPS anywhere? If so or if not, you should try changing all the preamp and power tubes (don't worry about the rectifiers).

I wouldn't think it's a choke problem. Even if it is, it's really easy to swap and a new one from Mercury Magnetics is $40. Since Mercury Magnetics typically charge quite a bit, I'd guess the choke is even cheaper from Mesa.

One more thing you could do for troubleshooting is to plug directly in to the loop return to isolate V4, V5 and the power section from the first three pre tubes. Don't really remember, but you might need to put a dummy cable in the loop send.

 

[lerxst88]

I would doubt it's a preamp tube because if the problem is taking down the LEDs, I would think it's somewhere in the main power supply. At least on the positive side if the high voltage is getting killed, it would basically be like putting the amp on standby so nothing is getting fried

 

[Anonymous]

I would doubt it's a preamp tube because if the problem is taking down the LEDs, I would think it's somewhere in the main power supply. At least on the positive side if the high voltage is getting killed, it would basically be like putting the amp on standby so nothing is getting fried

Oops, I missed that.

In that case, it looks like it'll have to do with the blue lead from the PT. The LEDs don't pass through the choke, so I still wouldn't think that's it. You might end up needing a new PT if that one is shot (the same lead sets bias levels and LEDs, but not the jewel light). I'd bet you don't, though it might be a bit of troubleshooting through the circuit to see exactly what the problem is.

 

[MesaENGR412]

Take it to a tech and have them check the resistors across the mains. My old Recto was doing this and it was caused by ( I believe) a leaking resistor. The tech said it doesn't happen that often, but your symptoms sound exactly like what mine were. Got the resistor replaced and it was good as new.

-AJH

 

[Pontius2000]

my Roadster did/does the exact same thing. The problem is the preamp tube that runs the reverb. I got that worked out with the Mesa guy over the phone.

now good luck getting Mesa to do anything whatsoever about it aside from sending you a new tube, like the tube is the problem (it's not, the amp is the problem).

and if your local certified Mesa tech is a go-getter like mine, he'll turn the amp on for an hour and then call you and say, "uh, I couldn't find anything wrong with it."


$2200 US dollars for this pile. I would've much rather spent $800 on a made in China amp. at least then, I wouldn't have expected it to be good. I don't know how/where you bought your amp, but if you have the option of getting your money back....run, don't walk, back to the place you got it from.

btw, I got my pile of **** DIRECTLY from Mesa which is an additional slap in the face.

 

[YellowJacket]

$2200 US dollars for this pile. I would've much rather spent $800 on a made in China amp. at least then, I wouldn't have expected it to be good. I don't know how/where you bought your amp, but if you have the option of getting your money back....run, don't walk, back to the place you got it from.

btw, I got my pile of sh!t DIRECTLY from Mesa which is an additional slap in the face.

LULWUT!!????? :roll:

My Dual Rectifier was made in '93 and it still runs fine. Not a problem with it.

 

[boss4]

my Roadster did/does the exact same thing. The problem is the preamp tube that runs the reverb. I got that worked out with the Mesa guy over the phone.

now good luck getting Mesa to do anything whatsoever about it aside from sending you a new tube, like the tube is the problem (it's not, the amp is the problem).

and if your local certified Mesa tech is a go-getter like mine, he'll turn the amp on for an hour and then call you and say, "uh, I couldn't find anything wrong with it."


$2200 US dollars for this pile. I would've much rather spent $800 on a made in China amp. at least then, I wouldn't have expected it to be good. I don't know how/where you bought your amp, but if you have the option of getting your money back....run, don't walk, back to the place you got it from.

btw, I got my pile of sh!t DIRECTLY from Mesa which is an additional slap in the face.

Take it easy men, it came with some malfunction, a good roadster dont come like that. There's a thing called warranty!

 

[Pontius2000]

Take it easy men, it came with some malfunction, a good roadster dont come like that. There's a thing called warranty!

Yeah, there is such a thing as a warranty, which I already explained......

They first told me to take it to their local tech, which I did. He called me and said, "I turned it on for an hour and can't find anything wrong with it". It was very obvious that he could not have cared less because his main business is building his own boutique amps so the whole "Mesa tech" thing was just secondary.

Then, I called Mesa and after about an hour on the phone the guy finally diagnosed the reverb tube as the problem. and he said, "ok, I'll send you another tube". worked fine for less than a month before doing the same thing again.

That's sure is an impressive warranty. This whole thing started less than a month after I bought it. That soon, that much money, bought directly from the factory, they should have replaced it immediately without even recommending a tech.

This always happens on channel 4 modern with high gain (though channel 2 brit also has it's own undiagnosed problems) when it's being PLAYED, not sitting idle. the tech lets it sit idle for an hour and can't find anything wrong with it, what a joke.

 

[Pontius2000]

LULWUT!!????? :roll:

My Dual Rectifier was made in '93 and it still runs fine. Not a problem with it.

Well good for you :roll: I guess that means you speak for every person that ever bought a Mesa amp :roll:

I bought a Fender amp that was made in Mexico that never had a problem (other than it just didn't sound good), does that mean Made In Mexico products are great?

I paid my $2200, that makes me part of the club. and this amp has been crap almost from day one, and the several times that I have spoken to Mesa people on the phone indicates to me that they have little to no interest in fixing the problem.

 

[boss4]

Take it easy men, it came with some malfunction, a good roadster dont come like that. There's a thing called warranty!

Yeah, there is such a thing as a warranty, which I already explained......

They first told me to take it to their local tech, which I did. He called me and said, "I turned it on for an hour and can't find anything wrong with it". It was very obvious that he could not have cared less because his main business is building his own boutique amps so the whole "Mesa tech" thing was just secondary.

Then, I called Mesa and after about an hour on the phone the guy finally diagnosed the reverb tube as the problem. and he said, "ok, I'll send you another tube". worked fine for less than a month before doing the same thing again.

That's sure is an impressive warranty. This whole thing started less than a month after I bought it. That soon, that much money, bought directly from the factory, they should have replaced it immediately without even recommending a tech.

This always happens on channel 4 modern with high gain (though channel 2 brit also has it's own undiagnosed problems) when it's being PLAYED, not sitting idle. the tech lets it sit idle for an hour and can't find anything wrong with it, what a joke.

Yeah, that sucks! Hope you get luck, cause they really are good amps and if you have bought a decent one, you would be a happy boogie owner.

 

[lerxst88]

Ok complaining about service given by Mesa or your local tech isn't really helpful in this case. Sucks you got a lemon but lets focus on the issue here. Lets get this recto workin!!!

 

[Pontius2000]

Ok then......to the original poster, the place for you to start is with the V4 preamp tube. that is the tube that the Mesa guy diagnosed as the problem over the phone. It's the tube that runs the reverb. take it out. the amp should run fine without it, but you just won't have reverb.

From your description, your amp problem seems to be EXACTLY the same as mine. The Mesa guy sent me another tube, which of course was not the problem. If my amp runs right for awhile without the V4 tube, then I'm going to unfortunately take it back to the "local certified Mesa tech" again and tell him exactly what the problem is so 'maybe' he can fix it. If I still can't get it fixed after that, then I will just buy a Reverb pedal and never buy another Mesa product again.

But yes, in short, start by looking at the V4 tube.

 

[AudioMonk]

Hello all. None of the preamp tubes control any of the switching in this amplifier, so a bad tube would not disable the power supply to the channel switching lights or matrix. The jewel light remains lit because it gets it's power from the 6.3 volt secondary directly from the power transformer. The problem lies after the 50VAC secondary tap of the power transformer which supplies low voltage to the switching matrix. An intermittent relay will cause this problem. If you're in Austin, TX or anywhere close I can help you. If not, let me know where you are located, I might be able to refer you to someone.

 

[MesaENGR412]

Hello all. None of the preamp tubes control any of the switching in this amplifier, so a bad tube would not disable the power supply to the channel switching lights or matrix. The jewel light remains lit because it gets it's power from the 6.3 volt secondary directly from the power transformer. The problem lies after the 50VAC secondary tap of the power transformer which supplies low voltage to the switching matrix. An intermittent relay will cause this problem. If you're in Austin, TX or anywhere close I can help you. If not, let me know where you are located, I might be able to refer you to someone.

That is it! Relay, not resistor. I knew it started with an "R"! Mine was "leaking" and would cause the amp to work for a while then cut out randomly, or just not work at all, having the jewel light and power tubes light up, but none of the preamp tubes and none of the channel lights.

On a side note, Mesa initially suggested tubes to be the issue at first for my amp. I got new ones, and it still didn't fix it. I think they trouble shoot with this because I would imagine they get tons of calls per day that ARE tube related, and if they suggested to take in EVERY head that merely needed a tube swap, then there would just be a flood of heads going back to shops and coming back to them for something so simple. When the anomalies come in that aren't tube related, then they tell you to take it to a tech or send it in to the factory. Mine was fixed via a tech in Charlotte, and it never had a problem afterward. If you don't have a tech you can trust, then either search for another one (they send a big list if you order it new and get the paperwork packett) or ship it to Mesa, and they should be able to get it back in working order.

-AJH

 

[SolDropplyr]

Take it to a tech and have them check the resistors across the mains. My old Recto was doing this and it was caused by ( I believe) a leaking resistor. The tech said it doesn't happen that often, but your symptoms sound exactly like what mine were. Got the resistor replaced and it was good as new.

-AJH

So I got a call from my amp tech yesterday and they are now getting signal... all tubes checked out, but now there's a ton of white noise. So now they are checking the resistors. Hopefully it won't cost me too much more bench time and they find the bad resistor. The tech said the same thing that this issue is not common and that it could have been pre-existing and the previous owner might have never know about. Either way I'm still without my DR for the time being. I'm hoping its completed by sometime next week as the techs backlog is pretty big. I'll keep you guys posted. Thanks for all of your suggestions and thoughts so far...

 

[volatileNoise]

This always happens on channel 4 modern with high gain (though channel 2 brit also has it's own undiagnosed problems) when it's being PLAYED, not sitting idle. the tech lets it sit idle for an hour and can't find anything wrong with it, what a joke.

Hang on, the OP is talking about a DR (an older one I think) and you are talking about your new 4ch head??