#1
Hi.

I'm getting a really bad microphonic chirping high-pitched noise off the gainier amp models from my VT, so I'm suspecting it's a cheap bad tube, and I'm planning to mail DV as I ordered the amp from them, hopefully getting me a new tube.

Anyway, as I don't live in England, I need to install the new tube myself, regardless of the way I'm going to acquire it. Just got thinking; Valvetronix amps use a 12ax7 tube in the power stage, so do I need to bias it? What do I need to keep in mind when I'm changing the tube so I don't get electrocuted?

Thanks!
#2
Mhm... AFAIK it is pretty much impossible to change the tube in the Valvetronix on your own, they are deep in the guts and chances you will kill your amp are high. I'd take it to the shop were you got it from and use the warranty if you have one.
My friend had the same problem and VOX fixed it for free and IIRC it wasn't the tube.
Gear:
Ibanez SZ320 -> Höfner Analouge Delay -> MXR GT-OD -> Laney GH50L -> T.C.Electronics GMajor -> Line6 4x12 w/ Celestion G12T-75


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"with golden hair and perfect eyes,

with hollow words and empty lies."
#3
I ordered it from Digital Village, and was just hoping I could fix it without sending it back to England... Bummer
#4
Of course you can try it, but you will void warranty. And if its not a bad tube, you will have to pay a lot more to get it fixed. I dunno, maybe the new VT's are better accessible then the older VOX my friend had, but I doubt it.



Edit: Is there still this grill on top of the amp where you can "see" the glow of the tubes? Maybe you can open it and change the tubes without voiding the warranty?
Gear:
Ibanez SZ320 -> Höfner Analouge Delay -> MXR GT-OD -> Laney GH50L -> T.C.Electronics GMajor -> Line6 4x12 w/ Celestion G12T-75


My Lyrics and Poems


"with golden hair and perfect eyes,

with hollow words and empty lies."
#5
Yeah, there's a small grill, but I can't find a way of removing it...


EDIT: there's also a grill on the back of the amp where I can see the circuitry and the tube, dunno if i could access the tube from there.
Last edited by Oldboi at Sep 28, 2009,
#6
What if your tube isn't blown, just your cable is broken?
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#7
Quote by JesusCrisp
What if your tube isn't blown, just your cable is broken?


Amp makes noise even without cable in amp's input jack.