Mesa Boogie 50 Caliber + low volume issue

[dknik]

Hi All!
this is my first post so I take the chance to say hallo to all of you guys!

here's the thing:

I've got a MesaBoogie 50 caliber plus that was not used for at least 6 years and was laying in a basement all that time.
The amp works, it turns on, the sound comes out, but the output is very low.

I know this amp it's a little tricky to set up properly, but when I tested out different setting with the 'volume', 'master' and 'lead master' knobs, every time the output was definitely not enough for playing with a band.

some of the knobs are scratchy when turning them around (and I think that's normal, given the state the amp was) but I would like to understand why the volume is so low...

probably it's a bit tricky to say without checking the whole amp, but could it be a tube issue?

thanks in advance!

[g1]

Try plugging your guitar into the FX Return jack. Turn up the master volume. Is the output level better or worse? This should help isolate the problem to preamp or power amp.
Yes, tubes are always likely suspects.

[quad4]

+1 on the effects loop (sort of)

Try plugging in the guitar as usual, but also add a 1/4 cable from effects send to effects return. That might make the problem go away. If so, then spray some contact cleaner (e.g., deoxit) on a 1/4 plug and put it in/out of the effects loop socket a few times (the return I think, but would have to check the schematic).

The issue in the above case is that there's a switch on the effect loop. If it's not used in a while, the amp thinks you have something plugged into the loop (but since you don't you get a low signal).

Other thing to try is another cable. They do go bad.

New tubes after that....

Great amp, by the way. Nice tones, but it weighs a ton for a 1x12.

[dknik]

Thanks for all the suggestions!

I tried all of those, and then I figured out what was wrong.

it's a bit embarrassing: when I was playing around with the effects send/return, I realized that the speaker was plugged in the direct channel instead of the 8 ohm plug I don't know how that happened..

luckily, nothing was compromised and as soon as the speaker was plugged in the 8ohm, the amp was back to the right loudness.
there's still a bit of crunchiness when rotating the knobs, but I will try the deoxit thing on some contacts and see how it goes...

thanks again!

[Chuck H]

Thanks for all the suggestions!

I tried all of those, and then I figured out what was wrong.

it's a bit embarrassing: when I was playing around with the effects send/return, I realized that the speaker was plugged in the direct channel instead of the 8 ohm plug I don't know how that happened..

luckily, nothing was compromised and as soon as the speaker was plugged in the 8ohm, the amp was back to the right loudness.
there's still a bit of crunchiness when rotating the knobs, but I will try the deoxit thing on some contacts and see how it goes...

thanks again!

This is common. When I was working a project with Dean Markley I had the notion of "re issuing" the old CD amp line. They were originally designed by Spectra I think and have a decent cult following on line and it was a trendy notion at the time. So when the first models arrived with that awful level adjust effects loop I had to wonder why the hell he did that.?. It's the ONE thing I would have changed. He shopped the amp around with some local hot shot players and getting the effects level adjusted correctly was a conundrum to about half of them and basically instantly put them off of the amp. First impressions and all. But Mark Castro very much liked the amp once the effects loop was sorted out. My point is that you're in good company.

I once tanked a sale on an amp because I had inadvertently depressed the "mute" switch when carrying it out to my living room. It's a nearly flush rocker switch located under the amp chassis and not visible!?! I couldn't figure out why the amp wasn't working. It was a half hour later when I was removing the chassis from the amp that I saw it