My guitar amp went pfffttt this afternoon and after some investigation I think it may be the one valve it uses. It’s an old Vox Valvetronix combo that uses one 12ax7 in the power stage. I suspect it may well be this as it rarely gets used and it’s the same valve that was in it when I bought it 15+ years ago! Also, it functions fine when I use headphones so I’m assuming the fault lies somewhere in the power stage rather than preamp?
I’ve spurged what amounts to the whole of my fun budget for the next millennia within the last 24hrs so before I punt out on a replacement to find it’s something other than the valve I wonder if one of you kind valve rats might have something spare (working obviously, but not necessarily of hi-fi grade and surplus to requirements ) that they might care to send me to try out. I’ll happily pay postage costs both ways & return it in the condition it arrives in, assuming it doesn’t blow up when I try it. Obviousy if that happens then I will consider it bought and compensate accordingly.
If it makes any difference the valve irself does light up when I power the amp on, but I presume this means bugger all?
Cheers Stu & Paul.
Stu, your offer of an Electro Harmonix valve does sound appealing as it’a an EH in there atm, but I must admit the thought of Sodders “rummaging” also has a nice ring to it as well.
Hmmmmmm…
Choices?
I’ve got a bundle of ECC83s for you to roll, a ‘cooking’ winged-C Svet, a vintage Tungsram, and the most interesting - a gold pin 5751: apparently some guitarists spaff their Depends over these. It’s basically a slightly lower gain/higher robustness ECC83, that in guitar amps distorts differently to the usual suspect (if distortion’s your thing…). I used them in a pre I used to have, and they suited it better than even foo ECC83s, really nice valves.
Cheers Mo,
That all sounds bloody brilliant, I just wish I had a scoobies chance of understanding what it all means? Despite being around valve guitar & bass amps for most of my adult life I think taking this one apart is the first time I’ve actually touched a tube.
Hours & hours of chin scratching ahead methinks!
Nah - unless you use a lump-hammer you can’t put this valve type in the wrong way round, so it’s literally a case of plug one in - strum whatever you fancy - and either say “Fuck it, that’ll do!” and leave it at that, or pull the first valve and replace with the next, strum again - see which oneyou prefer, &seq.
) that they might care to send me to try out. I’ll happily pay postage costs both ways & return it in the condition it arrives in, assuming it doesn’t blow up when I try it. Obviousy if that happens then I will consider it bought and compensate accordingly. 
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