Advice Needed: Victoria, EL34s+Gray Smoke

[highaura'd]

I finally got around to putting something else in my Victoria Regal II beside some JAN 5881
two brand new matched EL34s-(which the Victoria website specifically discusses this amp being able to handle)
put them in correctly-gave it about 4 minutes to warm up-put the amp on "on" and some fizzled sounds then "poof"-gray smoke-(that lasted at least 30 seconds)
i turned it off immediately-unplugged everything and now I need to know what might have happened--
I'm assuming I shouldn't put in other tubes as I probably fried something
I haven't had any problems at all and now this...
Any idea of cost best/worst case? is this something a good tech could fix?
I sent an email to Victoria, but so far was only told
"you must have either plugged them in wrong, or one was shorted."
Please help-I love this amp-

[rockon1]

Unfortunately what they replied sounds like the possible senerios. Sometimes the key on the tube pin is undersized so that its possible to install them incorrectly if your not careful. This seems like a 'worse' senerio. A shorted (bad) new tube can fry something too like a screen grid resistor. Hopefully if anything thats the case as its an easy fix. Im sure someone more knowledgeable will be along. Bob

[phsyconoodler]

Two possible things are happening here:
1) you have the tubes installed incorrectly as rockon1 suggested,or one of the EL34's was bad and shorted out causing a screen and/or circuit meltdown.Either way you need a tech.

[GearHeadFred]

Just plugging EL34s into 6L6-type amps will cause damage unless you rebias. EL34's will run way too hot in a setup for 6L6 type tubes (5881 included).

I suggest putting the original tubes back in and assessing the damage.

[rockon1]

Just plugging EL34s into 6L6-type amps will cause damage unless you rebias. EL34's will run way too hot in a setup for 6L6 type tubes (5881 included).

I suggest putting the original tubes back in and assessing the damage.


The Vic is cathode biased and has a special tranny. Pretty cool set up! Bob

"The Regal II is designed around a custom bifilar output transformer that is essentially two discrete transformers driving a common speaker load. This allows for the use of any combination of common 8 pin power tubes - from a single 6V6 delivering 5 watts of pure class A power, to two EL-34's for 35 watts. And because each tube is relating to its own independent transformer winding and bias resistor, any combination of different tubes types can be auditioned. Whether it be a single 6V6 or 6L6GC or a combination of the two (yes that's right, a 6V6 and a 6L6GC at the same time) the Regal II never needs biasing or adjustments when changing tubes. This versatility is also extended to rectifier tubes; the Regal II can accept any common 5 Volt rectifier including 5Y3, 5V4, 5U4, and 5AR4 with no adjustments nessessary."

[GearHeadFred]

OK -- How about pin 1? Unused on 6L6 type amps, but control grid on El34s? Sometimes used as a pass-through wire point on the socket of hand wired amps..

[rockon1]

OK -- How about pin 1? Unused on 6L6 type amps, but control grid on El34s? Sometimes used as a pass-through wire point on the socket of hand wired amps..


This allows for the use of any combination of common 8 pin power tubes - from a single 6V6 delivering 5 watts of pure class A power, to two EL-34's for 35 watts.

[Ronsonic]

If the builder says it'll take EL34, I'll believe they wired the sockets correctly and selected a bias resistor accordingly.

Have to go with the consensus so far, faulty tube or misindexed. Then again, parts do fail and every time you flip the switch there is a small but non-zero chance something will let go. I would not be at all surprised if it were something relatively simple, screen resistor, cathode bypass cap, something pretty cheap and easy.

Any reasonably competent tech can get this sorted for you.