Using 6l6's,el34's in a 5e3?

[chuckb]

Hey bruce, I have the 5e3 up and running with the higher wattage Weber trannys(20-25watts) and I was wondering if I can use 6l6's or el34's in this without having any problems? Would I have to use a differtnt rectifier tube eg;GZ34 etc, or would the nos 5y3 still be ok?

Chuck.

[Bruce / Mission Amps]

If the Weber PT and OT are at least in the 20-25 watt range and a normal duty cycle rating, ICAS Intermittent Commercial and Amateur Service (tubing industry) it will be a stretch but should be OK if the tubes are not underbiased and will be running cooler then what would be normal found. You'll have tweak the biasing resistor for this.
And, if the PT has enough 6.3vac current to support the EL34s, you'd have to wire the sockets for El34s. Most small 20 watt PTs have only a 6.3vac@4amp rating so watch that with EL34s.
There were quite a few amps made in the old days that used two 6L6s and a 5Y3.
If not, use a 5U4G.
Another difference you might find is that the EL34s and 6L6s are a lower zed tube. El34s usually around 3200 to 5000 ohms and 6L6s old cathode biased 6L6 amps usually ran at 5500 to 6500 ohms instead of the 8000 to 8500 ohms you'd find in a vintage 6V6 cathode biased amp like a 5E3.
4000 with either 6L6s or El34s is OK too... but with the 6L6s, that is something you'd see in a fixed bias amp with higher B+ then old tweed Fender amps.
I don't know what OT you are using and what the secondary output is but you can always run half the impedance on the OT to lower the zed or just use it as is.
If you are lucky, and the OT is 4-8 and 16 ohms, you could run an 8 ohm speaker load on the 16 ohm OT tap for half the impedance to the power tubes.

[chuckb]

Hey Bruce, thanks for the quick reply. I'm going to leave the amp as it is. I built this for a friend of mine who's always wanting to borrow my 5e3. I have Mercury Magnetics tranny's in mine. Will there be any diffeerence in terms of tone with the webers,also considering the fact that their 20-25watts? The PT has a 6.3v/5A winding and the OT has only an 8ohm output. I'm also building a Super tweed 5f4 which is almost finished,so that will give me a 6L6 based amp anyways.

Chuck.