Mesa roadster channel 4 keeps swelling in and out?

[Indigo]

not sure if it's a tube problem or not, since i changed tubes about 10 months ago.. but on channel 4 on all volumes.. the volume seems to get quieter and then swell back to normal. thoughts?

 

[Larrikin666]

I had a similar problem with my ENGL about a year ago. It ended up being a bad preamp tube.

 

[Indigo]

which preamp tube would be responsible for that channel. anyone know?

man, a disaster just occurred.
i pulled out a powertube from my roadster.. and that black part in the middle of the tube snapped in the socket. and it's very difficult to get out with pliers. heres a photo:

luckily, when i put the tube back into the slot without that black part the amp still functions fine. so i guess it really doesn't serve a purpose as far as the tube working goes. still going to have to get that out of there when i get new powertubes :-\

 

[MaxOfMetal]

Mesa has awesome customer service. Call them up and they should have no problem walking you through what you need to do.

As for that plastic part on the tube, it serves a couple purposes, one is to help with aligning the tube properly in it's socket, and the other is to protect the small "bulb" on the bottom of the glass tube.

 

[Indigo]

Mesa Roadster & Trem-O-verb High Gain Option with 6L6GC'sPrice: 143.75 Description: Need all the gain you can get from your Roadster or Trem-O-verb? This kit uses a matched quad of the JJ 6L6GC's for power, three hand picked high gain ECC83S's for V1, V2 and V3, two standard ECC83S's for V4 and V5 along with a balanced ECC83S for the phase inverter in V6. Scorching lead tones and better note definition!


thats the kit i have in there now. just my luck a preamp tube would go so quick : [

 

[MaxOfMetal]

If the tubes were brand new, and telling from the description you posted, you ordered from Eurotubes, try giving Eurotubes a call if it is a bad pre-amp tube. They may send you a replacement if it died prematurely.

 

[155]

Ive superglued those back on and had it last a long time...

 

[Indigo]

cool. thanks man!

@155: haha yeah. its gonna be rough to get that out of the socket i think. cause everytime i pick at it with pliers it snaps another piece off. delicate : / i might have to snap it off of every tube i buy in the future! : [

 

[Leuchty]

You could try screwing a small screw down the center of the plastic for more grip.

Very carefully of course.

 

[slayerrulesyo]

Couldn't removing tubes with pliers possibly shock you?? or the part that broke off.

 

[Larrikin666]

Couldn't removing tubes with pliers possibly shock you?? or the part that broke off.

That would imply that you're inside an amp while it is still plugged in. Rule #1 is "make sure the amp is disconnected from a wall outlet".

 

[MaxOfMetal]

That would imply that you're inside an amp while it is still plugged in. Rule #1 is "make sure the amp is disconnected from a wall outlet".

Amps still retain power thanks to the nature of their power storing components ALWAYS WEAR PROPER PROTECTION even if the amp is unplugged.

 

[Indigo]

i swapped around some preamp tubes V2 with V4, and then V3 with V5 and the problem is still there. any ideas?
about to just buy all new tubes and see if thats the problem

 

[krylon]

there's a post over at grailtone.com about this problem, iirc it was something to do with using a non-chinese tube in the phase inverter.

 

[Indigo]

well i just bought all new tubes. figured it beens a year.. might as well.

 

[MaxOfMetal]

Have you spoken to the nice folks at Mesa/Boogie yet?

 

[krylon]

i was wrong, its not the phase inverter, but the cathode follower tube.

The Boogie Board • View topic - Did You Get The Memo?

this should help mate.

 

[Indigo]

ugh. looks like ill have to try chinese tubes. but im not sure how this makes sense since it was working before and not now when i put jjs in?

anyway.. i swapped out all tubes today and still have the problem. waiting for a call back from mesa