triple rect not always working

[pathology knight]

Not sure how to explain this...

Every now and then, my triple rect sounds like *** when its turned on. Its been good the past couple weeks then yesterday, I put a new battery in my guitar (emg's) and the amp was quiet and flabby and overall sounded dead. Its done it to me 3 times now, the first at a show a month or so ago. I put in a different battery and it decided to work. Don't know if it actually made a difference, but it decided to work.

I'm always checking all my cables to make sure they're correct cuz I know one unplugged cable in my board kills it. Its very nerve racking not knowing what's going on.

The first time it did it at the show, I messed around with everything for half hour! It sucked. Then it just decided to come alive. I know my description doesn't paint a clear picture, but I'm hoping someone might know of what I'm talking about.

How long should I let it warm up before I switch the standby over? Maybe the tubes weren't ready? This is my first rect, and first tube amp and its super advanced for me. Sorry for the noon questions.

 

[afu]

Check your tubes. Make sure they're seated. Swap power tubes and see if it goes away.

Before turning the standby to "on", switch through the channels. It just gets the relays activating to remove the pops and to also make sure the loop's mosfets are turned on to allow the signal through.

Standby only needs a minute, maybe. The wait is to make sure the heaters are warm before the tube tries to conduct a signal. If the tube rectifiers are being used, they actually prevent signal from being amplified until they can conduct electricity; their heaters have to warm up first. It's like a built in soft start.

Solid state diodes don't need to warm up, so the standby is only really needed for the 30 seconds or so that the heaters need to get going for the amplification tubes. I find that a heated tube sounds better, sometimes. That's after playing it, though. The standby on its own isn't going to get the tubes to that temperature, since they aren't conducting a signal during standby.

If your tubes get hot and then crap out, it's probably time to change the power tubes.

 

[screamingdaisy]

Most problems with tube amps are tube related. If the amp is used there's a good chance the tubes in it were old and worn out when you bought it. I'd drop a new set of power tubes in it (the big ones, usually marked 6L6 or EL34).

If you're using the amp in silicone diode mode you don't need to replace the rectifier tubes.

Worn power tubes can sound quiet and bassy/dull.

 

[mesaboogieKT88]

power tubes lose the mids, highs and lows when they are worn, changes in volume is another symptom.

 

[screamingdaisy]

power tubes lose the mids, highs and lows when they are worn, changes in volume is another symptom.

Usually, volume fluctuations are a bad preamp tube in the V3 or V5 position. Those positions should be filled with a stock Mesa preamp tube, or a Chinese preamp tube. Russian tubes (Tung-Sol, EHX, etc) can't handle the voltages.

 

[pathology knight]

Thanks everyone for the help and info. I'll check and see what power tubes are in it and I'll check to make sure they're seated in there good.

Once the amp starts going, it has no problems and sounds great. It doesn't do this all the time, but its very worry-some.

 

[deeman]

Does this problem happen with the same guitar on other amps or with other guitars on this amp?

Have you tried going straight into the amp and bypassing the pedal board?

 

[pathology knight]

It does it with different guitars and even if I go straight in.