EL84 Linestage

[PakProtector]

hey-Hey!!!,
I built a balanced output linestage to run my active cross over a while back. Originally ran 12B4 and then before solving a microphonics issue converted it to run EL86's. The EL86 worked pretty well, and once the PS was separated from the signal chassis it was pretty quiet. This circuit is a LTP, running a 36 mA CCS in the cathodes and 20k plate loads on a 480V B+.

Once I had it rigged to run the EL86 I just swapped in EL84's. Gain is a bit higher ov course. Microphonics are gone... sonics are at lest as good as the 12B4( and an improvement over the EL86 ). Triode strapped in both cases.

All in all a fine experiment, and suggesting good results for the next set of amps that will run EL84 pentodes as their input stage( E-Linear, for pentode 6CB5A outputs ).
cheers,
Douglas

 

[diamondsouled]

Sounds like fun :yes: Do you, like Louis Wu, wait for magic smoke to let you know if you've over ampped the Pak library hardware?

 

[jaymanaa]

Good stuff Pak, thanks for sharing the results and keep us posted if the experiment continues.

 

[PakProtector]

Good stuff Pak, thanks for sharing the results and keep us posted if the experiment continues.

hey-Hey!!!,
First thing that popped into mind was an all-EL84 circuit. Linestage, front end and PPP power stage around a 5k a-a output trans... That and a 100-box of 6Pi14Pi-EV tubes...heh-heh-heh Then I could seriously simplify the tube collection.
cheers,
Douglas

 

[jaymanaa]

I've been looking at an all 6BL7 schematic from an old Hi-Fi magazine for an integrated amp. Same thing, I have tons of them, so I may give it a try.