HK Citation II output iron for EL34

[Blair]

Hi guys,

I have a friend with a pair of these that really wants to use EL34s. They are 3.8K with UL taps. I see the Dynacos are 4.3K for 35W. I believe the HK iron is good for around 60-70W at full bandwidth.

Would a single pair of EL34s work well with these, or would it be better with four EL34s per output transformer?

Thanks!

Blair[/quote]

[kheper]

Dynaco made a 40W mono-block, the MKIV.

http://home.indy.net/~gregdunn/dynaco/c ... index.html

I don't think you want to push 2 EL34s beyond 35W. In my st-70 (466Vdc * .50A), the tubes are operating at 23W idle. 4 EL34 tubes or 2 KT88s are better than 2 25W tubes. But, 2 EL34s will work fine, if you dial down the bias.

[Blair]

Thanks Joe!

He does not care about power out being 5-70W. Just EL34 as the power tubes. Im just curious about the 3.8K load being compatable with the EL34.

Think it's OK?

Thanks!

Blair

[kheper]

Yes. In the old tube manuals, there are specs for AB1 EL34s at less than 3.8K load. The Citation II has a 4ohm tap. He could use 8ohm speakers on them to double the load. This amp has a B+ of 455Vdc. It will be higher now due to an increase of AC voltage. Check that first, then adjust the bias accordingly. I'd shoot for 20W idle bias.

[Blair]

Hi Joe,

Thanks! I would be using my own power transformer that I know puts out around 450VDC on today's wall power.

Blair

[Blair]

I just realized I am calling you Joe! Jesus, I need to stop using my phone or everyone needs to adopt a very distinguishable monicker

Sorry!