Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: gja on June 03, 2020, 08:02:42 am

Title: 2e30 tube
Post by: gja on June 03, 2020, 08:02:42 am

Hi everyone,

Sorting out my stuff I found 4 x 2e30 tubes which I salvaged from a radio found in  a dustbin .
Can’t remember what the rest of the tubes were because it was all rusty so I just kept the tubes.

They are 7 pin sockets so before I actually buy the sockets andtry anything with them I was wondering if anyone had any experience, thought I’ d try them in a self split el84 amp which I like a lot.

Any thoughts?

Cheers

Title: Re: 2e30 tube
Post by: DummyLoad on June 03, 2020, 09:17:44 am

at first glance, they seem similar to the US 6AQ5/6005 - except that they have a heater center tap. 6AQ6/6005 use pin 1 & 7 for control grid - the 2e30 uses pin 7 for the heater center tap.

if you decide to try and install them in an amp built for 6AQ5/6005 you need to make sure that amps' pin 7 are NOT wired as a control grid. 

for a new build, graft them into any plan that uses 6AQ5/6005 and you shouldn't have any issues - i wouldn't try to bias them as EL84s. 


--pete

Title: Re: 2e30 tube
Post by: PRR on June 03, 2020, 05:00:40 pm

> similar to the US 6AQ5

Note no uni-potential cathode. This complicates biasing and heating, so much it hardly makes sense.

The real-good application is the original: a mobile transmitter. Can idle cold and heat-up fast on PTT.

https://frank.pocnet.net/sheets/096/2/2E30.pdf

Title: Re: 2e30 tube
Post by: DummyLoad on June 03, 2020, 06:23:25 pm

Note no uni-potential cathode

i missed that. directly heated, ugh! no need to wonder why there's a CT for the heaters. otherwise electrically it does seem to favor the 6AQ5.

--pete

Title: Re: 2e30 tube
Post by: gja on June 04, 2020, 12:12:34 am

Thanks for your posts, true I forgot about the cathode part...

I’ll keep them for some future, or sell them if anyone’s interested.

Thanks again!