Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Tone Junkie on March 08, 2011, 05:51:15 pm

Title: EL34 plate voltage
Post by: Tone Junkie on March 08, 2011, 05:51:15 pm

Just curious as to what el34,s will handle not on the upper end but on the lower. Ive heard when talking about EVH amps when there running plates at 400v there starving the plates is that true or can you run these at 340v comfertably without a problem and do they sound OK.
Sorry just thinking out loud I might tailer a build in this direction but dont want to waste my time if it wont work.
Thanks Bill

Title: Re: EL34 plate voltage
Post by: phsyconoodler on March 08, 2011, 06:04:28 pm

I've used EL34's in champs and other SE amps at 350v all the way down to 250v and biased class A.I don't think the 'starved plate' syndrome occurs if you up the current accordingly.

"tailer a build"

I wouldn't want you fixing my pants,I'll take it to a tailor thanks! :laugh:

Title: Re: EL34 plate voltage
Post by: bobmegantz on March 08, 2011, 06:39:35 pm

The best way to determine this is to consult the characteristic curves (which are easily found on the 'net).  It looks to me like you can easily go as  low as 200V and still operate effectively (making sure, as previously mentioned, to bias properly).

Title: Re: EL34 plate voltage
Post by: darryl on March 08, 2011, 07:10:48 pm

Several of my recent amp builds have used EL34's in push-pull fixed-bias, with 300-320 volts B+

Output power has been in the range 25 to 35 watts. The brand of EL34 has had a surprising effect on the output power achieved.

http://www.guitargear.net.au/discussion/index.php?topic=26455.0

(http://i497.photobucket.com/albums/rr333/valvetone/Vim%2030/front.jpg)

Title: Re: EL34 plate voltage
Post by: phsyconoodler on March 09, 2011, 10:20:41 am

You should put some pics of that awesome little amp in the Gallery. Nice.

Title: Re: EL34 plate voltage
Post by: Tone Junkie on March 09, 2011, 10:32:46 pm

Its suprising that the shugyangs would put out more than the other two darryl. Sorry phyconoodler I do try to look these things up but Im such a newbie I dont really understand what all Im reading, I know I ask a lot of dumb questions but you guys always answer, even better than that you teach me something everytime. In the last year and half I have 5 builds under my belt a year from now maybe 5 more Ive learned so much in that time, alot of it thanks to you guys. Even though i have an amp in my amp stand right now. I made another amp stand so I need to figure out what to put into it (LOL) In other words Im daydreaming about amps again   :toothy9:
Thanks Bill