Roadster Failure or something alike...

[ironjose]

Hey guys... i was very excited about using my new pedalboard on the Big 4 tribute I played last saturday... it sound awesome until the last song i played...

some popping and crackling started to sound... channel 4 (modern mode) started to fade out and then i switch to channel 3 (modern mode) which didn't fade out but it lost some gain and power...

I was worry because my friend's marshall blew a power tube (i guess it did, only one was glowing) so i came back to see mine amp and saw them with some blueish glow (I've read this is normal) but then again what happend to sound???

Some helpful information for you guys to know:

The power tubes are the stock ones
the preamp tubes are
V1 - new (with a few hours of playing) tung sol reissue
v2 - stock
v3 - new (with a few hours of playing) chinese
v4 - stock
v5 - new (with a few hours of playing) chinese
v6 - stock
the amp was on from 2pm to 3pm soundcheck, then went to buy a voltage regulator, the gig started at 5:15pm and ended at 11:30pm or so... dont really remember...

And you guys must be thinking if it was a Bruce Springsteen tribute well no... four bands played (i played on 3)... but the amp went on stand by between bands, 5 to 10 min between the two first bands and 25min at halftime (lol) then a small 20 rest trying to figure it out what happened to my friend's marshall and then the noise began... at the last song of the set (thank god)...

I was expecting new power tubes and today they came... but i have not put them in...

What do you guys think? :|

 

[ryjan]

Could have been a handful of things.
Bad power.
Poor connection somewhere.
Bad patch cable.
Power tube.
Preamp tube.
Internal amp problem.
Bad instrument cable.
Bad pedal.
Weak battery.
etc, etc.....

Without knowing your signal chain, the frequency of the problem, if you've experienced the problem since the gig, and what you've done to diagnose the problem we can't offer much.
Replace your tubes and report back after you are able to recreate the issue.

 

[ironjose]

Thanks Ryjan... until today i got the time to check the amp again... took it out of the 2x12 box... and connect it to a carvin 2x12 cab ... no noise nor bad sound coming out it... but i have the problem with loop again... i bet this is the problem which i dont know how to fix it...
does any body has this problem?

 

[ryjan]

Loop? What problem are you having with the loop?
First, it's always a good idea to verify power tube function by simply having a spare set handy to throw in. That and preamp tubes make up most of the problems.
Next , if there are no problems with nothing plugged into the loop but you have problems only when you have fx plugged in I'd suspect...
bad fx loop tube
bad patch cable
bad battery or power source to fx unit
bad fx unit
internal amp problem with the loop circuit.

I know this is vague but it's a complicated amp. :lol:

 

[ironjose]

well... the volume drops drastically and well i got in touch with the mesa guys... they told to me to change the preamps tubes in v3 and v5 and use chinese tubes in here... dont know what's the difference between the other 12ax7's but it worked... anyway after changing the tubes for new ones... sometimes i still here the drop volume issue... and have tried out taking the loop and sounds thin...
now i have new power tubes (sovtek 6L6wxt+) and i haven't tried the amp without taking out the loop... but no more problems...
even thou i havent used it on a normal basis... rehearse or gig...