Roadster..CH3 fade out.

[Crikey]

Just lovin this amp to bits but last night at a gig I had a bit of a problem, half way through the night ch 3 faded out on me, i went straight to ch 1 to finish the song, went back and it was just coming back, faded out again and back, was ok for the rest of the gig ??? anyone had that happen to them?

Anyway, I will now give it a hiding on 3 to see if I can get it to happen again, if so , might take it back for a check up.
anyway took a few pics with the phone
Gig. Dromana, Victoria, Australia.

 

[Storm]

Dude, let me know when you are doing a gig in Melbourne. I want to come and see a fellow Roadster owner at work!!! :twisted:

Ciao ...

 

[Crikey]

Dude, let me know when you are doing a gig in Melbourne. I want to come and see a fellow Roadster owner at work!!! :twisted:

Ciao ...

Likewise
have you had that fade out?

 

[Storm]

I never had had any channel fade out yet, touch wood. I mainly use channel four on modern though. We are playing tonight at Dream Nightclub in Carlton so I'd better get back to practising rather than internetting :lol:

Ciao ...

 

[Russ]

Might check out your preamp tubes... Sounds like one is on the way out.

 

[Crikey]

Might check out your preamp tubes... Sounds like one is on the way out.

The unit isnt that old, if it was a preamp tube, wouldn't that affect all channels?

 

[Crikey]

I never had had any channel fade out yet, touch wood. I mainly use channel four on modern though. We are playing tonight at Dream Nightclub in Carlton so I'd better get back to practising rather than internetting :lol:

Ciao ...

Good luck tonight, mate if I had the stamina I'd poke my head in

 

[Storm]

No worries mate, many more chances to catch each other in action.

Ciao ...

 

[CudBucket]

That's a preamp tube about to fail if there ever was one.

 

[Russ]

Preamp tubes can be duds right out of the box. If it is say your lead gain and say your effects return you would never hear it on the clean channel if the lead gain half was the culprit. That was just an example but often amp manufacturers will split tubes across a couple different duties. Sometimes it will be simpler like V3 is all lead gain on both halves or effects send on one side of the tube and return on the other. It is all amp specific though. I would get a couple new tubes and swap them through to see if you can find the culprit basing your experimentation on what seems to be the biggest problem. Sure if V1 was going bad you would find your problem on all channels. In the case of gain that is cascading you might find that your 2nd gain stage affects your 3rd and so on. Therefore you isolate where the earliest in the cascade that you are seeing an issue and then try there first. Another tube that affects all channels is the phase inverter. Guitar amps are not the original purpose of tubes. In fact, guitar amps are really hard on tubes. Even tubes that were spec'd for a life of say 10,000 hours can be shortlived in a guitar amp. There again, even a screened tube can fail immediately. I have personally seen tubes that were crap right out of the box. Conversely, I have also had tubes that I wished would just die but wouldn't.

 

[chennie]

Ah I see...you're playing a Marshall cab, **** isn't made for a Mesa dude... =)

just kidding, I have some fade trouble as well, don't know the reason. I suspect loose fittings of tubes, because it always happen when I replace the amp.

 

[Crikey]

Preamp tubes can be duds right out of the box. .

Hey Russ, thanks for that info mate, I'm a real noob when it comes to valves but I do understand what you are saying.
Is there anywhere I can get a schematic of a roadster so I can tell which valves are which? And is there a good online valve merchant?
Cheers

 

[Crikey]

Ah I see...you're playing a Marshall cab, sh!t isn't made for a Mesa dude... =)
just kidding, I have some fade trouble as well, don't know the reason. I suspect loose fittings of tubes, because it always happen when I replace the amp.

you had me for a bit :lol: I havn't heard my head through a mesa cab but am happy with it's performance now,how much difference would there be? I had a JCM900 head so I just kept the marsh cab, mesa cab was expensive, I had forked out a kings ransom for the roadster.
aahh ok, i'll check all my tubes for loosness.
What do you mean , "because it always happen when I replace the amp"

 

[Russ]

You should be able to get the information you need regarding preamp tube duties from the manual.

Many like Doug's tubes or Eurotubes for ordering online. There is also KCA, Watford, Tube World, GT and Mesa of course.

 

[Crikey]

You should be able to get the information you need regarding preamp tube duties from the manual.

Many like Doug's tubes or Eurotubes for ordering online. There is also KCA, Watford, Tube World, GT and Mesa of course.

I am at work atm, when I get home will go through the manual, I remember the section where it gives a bit of valve theory, a lot went over the head I'm afraid (getting too old ) If I could get my hands on a schematic(or simple pic with valve names.) it would be a huge help.
Again thanks for the info, I will bookmark those valve sites.

 

[domct203]

The Roadster's tube functions are the same as the RK.

V1A=First Gain Stage ALL Channels (Input Stage)
V1B=Second Gain Stage ALL Channels (Input Stage)

V2A=Third Gain Stage Ch's 1 & 2
V2B=Third Gain Stage Ch's 3 & 4

V3A=Fourth Gain Stage Ch's 3 & 4
V3B=Tone Stack Driver

V4A=Reverb Return
V4B=Reverb Driver

V5A=FX Loop Send
V5B=FX Return

V6A&B=Phase Inverter

Hope that Helps!

Dom

 

[Crikey]

The Roadster's tube functions are the same as the RK.

V1A=First Gain Stage ALL Channels (Input Stage)
V1B=Second Gain Stage ALL Channels (Input Stage)

V2A=Third Gain Stage Ch's 1 & 2
V2B=Third Gain Stage Ch's 3 & 4

V3A=Fourth Gain Stage Ch's 3 & 4
V3B=Tone Stack Driver

V4A=Reverb Return
V4B=Reverb Driver

V5A=FX Loop Send
V5B=FX Return

V6A&B=Phase Inverter

Hope that Helps!

Dom

thanks dom, printed it out.

 

[Storm]

Hehe, yeah I saved that too for future reference. Thanks Dom.

Ciao ...

 

[Crikey]

Hehe, yeah I saved that too for future reference. Thanks Dom.

Ciao ...

how did your gig go last night? .

 

[Storm]

Yeah it went pretty good even though we were a bit loud, no thanks to the sound guy :lol:
When are you gigging next?

Ciao ...