EF86 for line stage - any good?

[nzoomed]

Im considering using EF86 for the line stage in my next preamp.
I believe that E88CC are one of best tubes for the phono stage, and will be using them for this, but as far as line stages go, I dont see many projects out there that use the EF86, but from what ive been reading, the best way to do it is using them as a triode.

Any recommendations if this is a good idea or not?

 

[mctavish]

It is a very low current tube, the opposite of what you want to drive anything less than a very high impedance.

They do perform and sound good in triode mode though, I have used one with a mosfet buffer in a single ended amp project a few years ago.

The 6DJ8 is a perfect tube for a linestage, that is, if you need the gain.

 

[nzoomed]

I really only need the gain for the phono source, although i find some digital sources can also be low output.

 

[DF96]

The EF86 is a low noise high gain high impedance valve, even when triode-connected. For a line stage you need a low gain low impedance valve, and noise is not usually a problem.

 

[JonSnell Electronic]

ECC83/8 is best for line stages and tone control systems.
EF86 is best for phono preamp with 220k output impedance, so buffer it with an ECC83/8 cathode follower.

 

[PRR]

EF86 Triode is 19K plate impedance at 3mA. We could draw a loadline like 30K, get 11K output impedance. This might be fine for shorter cables to a 470K input power amp. This would be bad for >10' cables or into modern 10K input power amps.

And in hi-Z the gain would be >20, which is more than we usually want in a line stage.

If all your sources are low-Z, you could wrap NFB around, lower gain and Zout and meter-THD. But then many other utility tubes would work as well.