Mesa Roadster...volume swelling.

[cholera]

Having never had a single issue with this amp, the day after I list it on Trade me I plug it in and discover the volume is swelling in and out. It's been a while since I had a dodgy amp so can't remember if this is due to power amp tubes (it shouldn't be, they are only maybe 2 years old) or preamp tubes? Or something completely different. It doesn't seem to be channel specific, and I was running nothing thru the fx loop at the time either, one cable straight into amp. ( I did try different cables too of course....) Any ideas? Im going to have a look at the mesa forum site, I do have a set of the original powere tubes so I can swap them out, but I only have one spare preamp tube, maybe I'll try that in each position one by one...

[slash-ed]

Have you tried it through other power outlets in your house? Could be a power flux issue?

[RuBear]

Turn your trem pedal off.

Also this might help http://forum.grailtone.com/viewtopic.php?f=4&t=25102

[RuBear]

Have you tried it through other power outlets in your house? Could be a power flux issue?

flux capacitor stuck in the mains?

[cholera]

Not tried that Ed but it's worth a shot.....and I was thinking the first post would be about getting rid of the volume pedal, not a trem....imagine my suprise when I get an actual on-topic reply!!!!! OMG!!!

[cholera]

Oh and thanks Rubear....the joke was redeemed by a worthwhile link.....

[capt abaham]

does the roadster have a rectifier tube?

could be that failing, or power tubes depending on how hard you have pushed them in the last two years

[cholera]

I didn't even consider the recto tubes. I never used them in my last triple recto so I tend to forget about them, but I do have channel one and two set to tube rectification in the Roadster ( so yes it does have rectifier tubes). I guess I can switch to solid state and see if that works so I can at least eliminate that problem. The power tubes have really had little use all things considered, and this whole preamp tube buisness is confusing as hell so Im gonna hope its one of the rectifier tubes!

[capt abaham]

how did it go?

[cholera]

Just got home from work and the missus has invited non guitar folk for dinner so Im gonna have to wait for a bit....I'll be sure and post results!

[cholera]

So upon switching all channels to diode as opposed to recto tracking problem was completely gone! So mixed feelings being as I figure I'm up for a couple of recto tubes, but at least I know what the problem was...... then swititched back to recto tracking thinking I'll get cut out again, but no, everything was fine. Back to Diodes and after a couple minutes here's my swell coming back!!! So, all I have learnt is its not the recto tubes!
Anyway, had a 30 minute break then went and played for about an hour, switching channels, turning fx loop on and off, messing with the wattage selector, and no problems at all....

Brings back bad memories of Marshalls that MOSTLY were fine all the time but always left me slightly nervous at gigs.

[capt abaham]

fx loop ay, i know Marshalls suffer from dirty contacts between the FX loop input and output jacks and a squirt of cleaner on a cotton bud fixes that up real quick.

dont know about Mesa`s though.

[cholera]

Someone else recomended the old "tap the preamp tubes with a pencil to see if they make weird noises" trick....going to give that a whirl now too. Can't hurt to clean the jacks in the loop either tho I guess. Thanks Capt.