Amp has lost its character?

[wilkinsi]

I know how my Randall RT50C sounded when I first got it. That "sound" which I distinguish by setting my Boss GT-10 to one specific patch. That patch does not sound like that anymore. Another example is when I add/remove chorus from a patch, there used to be a massive difference. Not anymore. I also noticed other patches starting to sound either nasal, honky, fizzy, etc.

Are my tubes going, are they self-unbiasing, or is the amp now reaping the penalty of numerous occasions where the stand collapsed underneath it? I'm hoping its just the tubes. I can't afford a replacement amp and the RT50C is discontinued.

[xenophobe]

Most likely a tube going bad or getting old. One thing about tube amps that I don't like is that they seem to sound different at different ambient temps or something. I'm fiddling with a tube amp far more often than I am solid state. I dunno.

[warlok]

Try swapping preamp tubes around or if you have a spare swap into each spot separately. Guessing one may be a loop buffer tube and could be the problem(??).. And yes, the power tube bias adjust is external (and awesome feature!!) like my RM amps. Obviously you haven't checked the bias, so grab a multimeter (on MV setting) and check that first.

[Cygnus X1]

Are my tubes going, are they self-unbiasing, or is the amp now reaping the penalty of numerous occasions where the stand collapsed underneath it?

Self unbiasing?
Sorry, that's just hilarious.
Quick peek on the interwebz tells me it has bias taps on the amp, so it will need to adjusted when the power tubes are replaced.

And, stand collapsing?
Absolutely.
Get it checked out before the thing explodes or melts down.

[wilkinsi]

Cyg, I know fuck all about amps... but I'll get the tubes replaced and biased asap.If I was using this amp for 4-8 hours a week, how long realistically should the tubes last?

[Cygnus X1]

Cyg, I know fuck all about amps. I'll get the tubes replaced asap.

That's cool.
Glad you finally went with a tube amp after all these years of myself and others suggesting them.
Pays to learn though...so you don't get screwed by a "tech".

[RacerX]

It's just depressed because it lives in England

[Cygnus X1]

This website is really old school but it has been a great resource for all levels of education.
Choose what you want and learn...

http://geofex.com/tubeampfaq/taffram.htm

[wilkinsi]

That's cool.
Glad you finally went with a tube amp after all these years of myself and others suggesting them.
Pays to learn though...so you don't get screwed by a "tech".

I bought that amp in June 2011 you dolt!

[Cygnus X1]

I bought that amp in June 2011 you dolt!

Off to Rsamcker you go!

WTF do I care?

No, I don't know exactly when you got it...I DO remember distinctly suggesting a long time ago to get a tube amp.

[Twitch]

Actually, tubes will "unbias" as they age. That's what happens when they break in or get old. If you put new tubes in it and bias them correctly, about 10 hours or so of playing later they will need biased again. That's normal. From then on you'll have about 6 months to a year before they sound crappy again and the cycle will repeat its self. That's tubes baby.

Additionally, it could be your ears. Ill have an amp or a patch or setting I think sounds killer for some undetermined amount of time and then, like that, one day ill fire it up and go "eww". Nothing's changed but my taste. That's guitar baby.

[wilkinsi]

Off to Rsamcker you go!

WTF do I care?

No, I don't know exactly when you got it...I DO remember distinctly suggesting a long time ago to get a tube amp.

Ha, I thought that troll was with you.

[VitaminG]

Try swapping preamp tubes around or if you have a spare swap into each spot separately. Guessing one may be a loop buffer tube and could be the problem(??).. And yes, the power tube bias adjust is external (and awesome feature!!) like my RM amps. Obviously you haven't checked the bias, so grab a multimeter (on MV setting) and check that first.

if it has the same external bias adjust as the MTS series, do what warlok says - get a cheap multimeter and learn to do it yourself. It's quick, it's painless, and you don't have to wait for a tech to get around to looking at your amp.

btw, preamp tubes don't need to be biased. So just try swapping a spare through each position (also as warlok told you) and see if you can identify if it is a problematic 12ax7.

[Hellbat]

Are we sure it's the amp and not the player?

Have you tried having another guitar player plugging in to make sure that's not the problem?

[wilkinsi]

Its the poweramp tube(s) that need replacing and biasing. I don't use the preamp, only the FX return which feeds the main out of my GT-10.