Looking for tube for application

[dsavitsk]

I am searching for a tube to use in a particular application, and would like some suggestions.

I am working on a headphone amp that uses a single tube, single ended, transformer coupled to the headphones. So far I have been working with a 6N6p with both sides in parallel. This works pretty well -- plenty of power and decent sound (warm and syrupy), but I'd like to try some other options, perhaps something with a little more gain. The 6C45 looks promising, as does a parallel 7119, but I'd also like to see if anyone has any other suggestions.

Also, I have found that unbypassed resistor biasing seems to sound better to me than LED or bypassed resistor biasing so far, but this does steal a bunch of gain. So, biasing suggestions also welcome.

[Geek]

How about this little parafeed project ?

Could easily be adapted to dozens of tubes.

[pmillett]

I've done it with the 6c45pi and Sowter 9351S OPT's, it worked well. You could also try triode-connected video amp pentodes (12HG7, etc.). Look out for the miller capacitance, though, on any of these.

Pete

[Alain Dupont]

dsavitsk,

There are 2 excellent articles from John Broskie:

http://www.tubecad.com/2006/11/blog0086.htm

with a 6BQ5

and the famous Aikido:

http://www.tubecad.com/2006/09/blog0081.htm

Regards.

Alain.

[phn]

The 6C45 with battery-biasing (that's the name for it?) should be nice.

If you like it cheap--no OPTs--then this should be nice as well: http://www.jogis-roehrenbude.de/Lese...C3g-KH-Amp.htm

[dsavitsk]

Originally posted by pmillett
You could also try triode-connected video amp pentodes (12HG7, etc.). Look out for the miller capacitance, though, on any of these.

I had not thought pentodes at all. Looks interesting.

Originally posted by Geek
How about this little parafeed project?

Originally posted by Alain Dupont
There are 2 excellent articles from John Broskie:

Originally posted by phn
If you like it cheap--no OPTs--then this should be nice as well: http://www.jogis-roehrenbude.de/Lese...C3g-KH-Amp.htm

Thanks for the suggestions. I should be clearer. I have the output transformers (James) and have the circuit working. I am just looking for some different tubes to try to explore the topology.

I have taken to building little circuit boards that have the tube, and the associated caps/resistors/LEDs/etc. on board and a couple of terminal blocks so I just pop them in and out of the circuit to explore different options.

So, I am just looking for other tubes to try.

-d

[Zen Mod]

EC8010,EC8020,E810F..........any high S toob

[jeff mai]

Originally posted by dsavitsk
I have the output transformers (James) and have the circuit working.

The specifications of your transformer will limit the choice of tubes. Max current, primary inductance, and impedance ratio would be good to know before making suggestions.

[dsavitsk]

Originally posted by jeff mai
The specifications of your transformer will limit the choice of tubes. Max current, primary inductance, and impedance ratio would be good to know before making suggestions.

Transformers are James 6115HS. 5K:8 (phones are 32R and I have a 32R resistor in parallel with the phones, so 10K:16), 70mA, 10W.

http://euphoniaaudio.netfirms.com/ea...7652c79aa392aa

[kevinkr]

I use 5842 (417A) in a white cathode follower to drive my headphones, I think that one per channel into your 5K transformer would probably rock.

I actually have a fairly cheesy circuit on my site that could be adapted to work in your application. check under the project pages, you want the pre-amp section.

Note there are reasonable models available for the 417A so you can simulate this in your favorite flavor of spice..