Look for a beefy driver tube.

[Shoog]

I am currently running a ECL82 as a driver tube pushing an interstage transformer. I am not that happy with its sound so am looking for a substitute.

I need a driver which will work with the following criteria;

Va 100V
Ia 40mA
Gain of about 15.
Preferably 12.6V heater.
Preferably 9pin base.
Triode or pentode


I have spotted the 6H30 which looks just the job, but the heater is a problem. Also they seem outrageously expensive. Any good sources ?

I would appreciate any other ideas.

Shoog

[JoshK]

6n6p is similar to the 6n30p, but cheaper. Same problem with heater however. Unless you series connect the heaters.

[Wavebourn]

Originally posted by JoshK
6n6p is similar to the 6n30p, but cheaper. Same problem with heater however. Unless you series connect the heaters.

6N6P is more linear than 6N30P, and in case of a stereo amp filaments may be connected in series.

[Shoog]

I was thinking of paralleling the sides of the 6H30 which would give me 20mA per side and a grid bias of about -5V - plenty of headroom. It would then let me series connect the heaters. At this operating point it should give a very long service life to.
The 6N6P looks a bit cramped at this sort of operating point.

Shoog

[Eli Duttman]

Shoog,

The 5687 is a possibility. You'll have to settle for I_B = 37 mA.

5687 data sheet here.

[Wavebourn]

EL84 triode strapped is another option.

[Shoog]

Running a single 5687 for both sides of a stereo pair is pushing it over it plate dissipation (just). Of course I could run the two triodes in parallel.
I have used the 5687 as a preamp tube and always had issues with hum, I really want to avoid the complexity of DC heaters.
A definite contender though and I even have some.

Shoog

[Shoog]

EL84 triode strapped is another option.

I thought of that already. works on most levels, but would it be happy at 100V.

Shoog

[Wavebourn]

[Shoog]

Not really then.

Shoog