Switching to EL34 from 6L6GC - Heater Current

[gar13]

Hi all!

I am finally getting around to finishing up a ODS clone. I used a set of schumacher transformers that I believe came from an old Carvin amp which had a quad of 6L6GCs (unknown model). Bias wire is blue, and there is 12v or 24v (can't quite remember and they are currently zip tied and heat shrinked) winding with orange leads that I am not using.

I have it up and running with Winged C 6L6GC, but realize I like the tone of EL34 type clones better. I tried a a quad of EL34's for about 5 minutes with a dummy load and no signal going into the amp. I measure the heater voltage to be a stable 6.23v.

If the heater voltage remains stable, is this an adequate test to determine if the power transformer can handle the heater current? Are their any other ways to test?

Thank you,
Dave

[fdesalvo]

If the PT was cool at playing volume, it should be ok.

[stratele52]

If your heater voltage is not less than 6.2 you are alright. If you take mesurement with good multimeter....

[DummyLoad]

if you're worried about killing the 6.3V winding then run 1 pair of EL34 and double speaker load.

respectfully,

--DL

[jojokeo]

I tried a a quad of EL34's for about 5 minutes with a dummy load and no signal going into the amp. I measure the heater voltage to be a stable 6.23v.

If the heater voltage remains stable, is this an adequate test to determine if the power transformer can handle the heater current? Are their any other ways to test?

You're not pushing the tranny in a running condition w/ your "current" method... pun intended, sorry had to say it but it is a true statement. You're likely okay but feel the tranny after cranking w/ signal for a half hour or more in an actual playing condition while it's also pushing out maximum plate & screen currents too. This is also important, not just heater capacity. The other thing to consider is the actual operation environment - how it's mounted in your cab and traps heat adding to overall heated conditions. Check it every few minutes w/ your hand and feel how hot you can get it to go. If you can keep your hand on it, you're okay. If not, be concerned and/or do what Dummyload suggested. This will tell you a lot w/out wasting time or fretting too much by over analyzing everything.

[stratele52]

With 6.23 volts, your transfomer have enough power. Heater power avalaible is directy proportionnal with general trasnformer power . You could use ithis tranny  safely.