E80f sub for ef86

[Noskipallwd]

Hello, anyone ever sub the e80f for the ef86 in the Eros? I saw it in the tube equivalent thread with a question mark after it. I have been told it was a direct replacement for the ef86. I have two Mullard e80fs with gold pins, can't remember why I bought them or where I bought them from. Would be nice to use them.

Cheers,
Shawn

[Jim R.]

Shawn,

I believe Paully did this and said they were nothing special.  Hope he'll chime in here.  I too have a couple of these somewhere in my stash but don't think I'll use them.  Look in the 6br7 thread -- I think that's where he mentions giving these a try.

-- Jim

[Paul Joppa]

They are somewhat similar, and have the same pinout. I don't remember from the previous thread whether they bias up close enough to work reliably without changes. It does take 50% more heater current, which may shorten the life of the Eros power supply; I can't at this point calculate any estimate of whether that is significant or not.

It does seem to be something special - it has the "no interface" cathode, which is thought to be valuable, and the specified noise level is better, at least in the Phillips spec sheet. They are probably best used in tube microphones, since they are specified for electrometer service (very very low grid leakage). That's just a guess though - been a long time since I talked to the real microphone experts.

[Paully]

We tried the EF40 and had multiple versions of it, none of which were particularly appealing to Grainger or myself.  They were fine, just not great.  Those required some rewiring.  I stopped with the 6BR7, which also required some rewiring, because I liked it so much.  I don't have any familiarity with the E80f other than reading about it on the tubes asylum where they say it is a drop-in replacement for the EF86.  Whether that works on the Eros or not, don't know!

[Noskipallwd]

Looking at the Phillips data sheet they are similar electrically except for the heater current. I had just seen the Mullards like I have recommended for preamp service, suppose to be very low noise. I guess I could roll them in for a short experiment, take some measurements and listen, that shouldn't cause any harm to the amp. Or is this not a good idea?

Cheers,
Shawn

[Noskipallwd]

Decided to leave these tubes alone, maybe I can sell them to a guitar guy, they are beautiful tubes though. Thinking about experimenting with the 6br7. Thanks for the responses all.

Cheers,
Shawn

[Brillo]

When Paully posted about his switch to the 6BR7 and the positive results, I thought I'd give it a try. The socket rewiring is super easy, and 6BR7s are inexpensive. The sonic improvement, at least for me, was immediate. I was having trouble with tube rush with the ef86s, but this swap took care of that problem. I haven't contemplated a change to another tube. No need.