Ceriatone Forum

Is anyone using EL34's in there Bluesmaster or HRM? If so what mA are you setting the bias for? I'm using Winged C (SED) 6CA7's.

Hi,
In a Bluesmaster at 470v I was happy with 39 ma

Check this out:

EL34 - 25W  Hot (70%) Avg (60%) Cool (50%)
300V               58mA       50mA         42mA
325V               54mA       46mA          38mA
350V               50mA       43mA          36mA
375V               47mA       40mA          33mA
400V               44mA       38mA          31mA
425V               41mA       35mA          29mA
450V               39mA       33mA          28mA
475V               37mA       32mA          26mA
500V               35mA       30mA          25mA

Cheers

Sorry, your power transformer is made for 6L6 not EL34 and will not handle the additional current needed for those filaments......

Thanks Jon, my bad I forgot. I got a quad of them SED's and didn't want to blow em up  ;D

In my correspondence with Nik during the ordering of my amp I asked about using el34's, and he replied that the amp was wired in the output tube sockets to take them, it's part of the regular design on the 50w HRM I own.  There is more than enough capacity in the PT to handle the increased heater current from a pair of el34's.  One guy on our forum is running a pair of 6550's in his 50 watter biased at 50mv, running at very loud volumes for long periods and he reports that the PT  still runs cool and has been reliable for several months.  The PT in mine runs cooler than nearly all the other guitar amps in my stable.  I am running vintage el34 RFT's at 39 and 42mv.  They are slightly mismatched, and the tones/sustain are wonderful with them at that setting.  Dropping the bias down 3-4mv yields a slightly brighter tone, and a bit less bloom on the long sustained notes.  I have also run a pair of very tightly matched vintage Sylvania 6l6gc's at around 35mv, fat, warm and huge tones gush out of that amp with those.

I don't have a Ceriatone Power/Output Trafo's in my amp though. I have a Fender Twin Reverb Pwr Trafo and Tonemaster OT so I am limited to 6L6's to run @ optimum unfortunately.

If you find out the specs on that PT you will know fo sho on the heater current thang.   EL34's draw around 1.4 amps apiece for their heaters.  Impedance on the primary side of the OT will be slightly off running el34's, but that probably won't be a serious problem. 

That's a classic Internet misinformation statement...  If you use the Merc trannies spec'd by Nik, and I understand that he specs 2 different trannies depending on whether you intend to use 6L6 or EL34, either set will handle either power tube. The Mercs are built like tanks and have power to spare.

I have replaced power transformers in more than a few Twins over the years for folks who tried running EL34s in them. From what I've seen it's a crap shoot, sometimes you can be OK and sometimes they just get too warm and fry themselves. And as Greg already mentioned, he is not using Mercury stuff. He also plays very loud so since I built his amp I advise against it. But of course you can try it if you like!
I'm building a #183 for someone now using those same new tubes, using a TXFR rated for that current. I'm expecting good sounds!!

I tried the SED EL's @ 32 mA in my HRM and I could tell the feel of the amp was drastically different in terms of feel. Very stiff for my taste's. Considering the Bluesmaster PI and HRM OD is very squashy feeling (in a good way) with 6L6's.

  My conclusion is the amp was less tastefull with EL's (using Twin Iron)for my needs.

  I am considering getting the Bluesmaster PI changed to Skyliner spec as I have the Quinn 183' preamp coming soon. Utilizing the HRM preamp and the Non-HRM 183 preamp together (on a switching system) with a skyliner spec'd power amp will give me the best results and tons of tone options IMO. Essentially I'd be turning my rig into a Glaswerks SOD II or Fuchs Triple drive type amp. 

who says you cant use EL34s? I used SED and Shugaung in my 50 watt. 42mA was my prefered setting.

For all the nay sayers im currently running KT88's at 50mA now without any mods. Been 6 months nothing has blown up..