EL34

[Railway Surfer]

Hi Guy's
My amp (Vox ac100cp) has an EL34 that doesn't seem to be working. Is it still safe to use with just the other 3 going??? Also what valves do you guys recommend replacing the original Ruby valves with??? Cheers

[AmpShop]

Not a good idea to run it with 3 output tubes. Pull another one out - they are paired "inside-pair, outside-pair" so make sure you pull the corresponding tube - and then switch the impedance selector to half the normal setting e.g. if 16 ohm with 4 tubes, set to 8 ohm with 2 tubes.

Any EL34 type tube works well with these amps. I've supplied the Ruby EL34 where the customer insisted on it (they're re-branded chinese Sino/Shuguang EL34B) but have also had good results with the JJ E34L.

Your main consideration is making sure that the replacement tube(s) match the existing tubes - when I say match, I don't mean brand-wise, but plate current draw and transconductance.

If you'd like to send the exsiting 3 tubes to me, I'd be happy to match you up a replacement (I suggest a replacement pair, leaving you 1 matched spare tube).

[Railway Surfer]

Wicked
Thanks for the help, I won't touch anything as the amp is under warranty. I would like to get a price off you on some replacement tubes for the future though. Cheers

[Railway Surfer]

Surely not 2 week old ones?

[AmpManAsh]

Surely not 2 week old ones?

Especially 2 week old Chinese ones.

What’s wrong with the valve?

[AmpManAsh]

Iv had an el34 that melted the solder on the pins and caused me some trouble, I re-soldered and had no problem since.

[Railway Surfer]

No Idea what the problem is, I'm waiting on a reply from the shop I bought it from. I'm not touching it until I have an answer or else I'll void the warranty. The valve is the only one that doesn't glow? Thanks for your replies.