6AU6 vs. EF86?

[Alexo]

6AU6's are incredibly cheap and easy to find in many an old radio, I have about 8 or 10 in my stash right now, all of which I came across by accident, versus 0 EF86's I've been able to find, so...

Does anyone have experiences with these? I am embarking on an 18watt-ish amp that will have one 6AU6 channel, in hopes that it may capture some of the magic of the EF86 at a much smaller cost (and socket )

Do they sound similar to EF86's? The datasheets have a lot of very helpful info, but I would appreciate any tips anyone has for wiring them up, I've attached the schematic I've worked out, how's it look?

...Thanks!

[Johnhenry]

go to schematic heaven and look at a 303a or a 303 Harmony amp in the Bargin Bin Amp section, one of the version's used the 6au6 tube on the input.
johnhenry

[Alexo]

Thank you , Johnhenry.

After further research, I have found references to the 6AU6 being terrible for audio and also maybe needing DC filaments to avoid excessive hum.

I think I'm just going to bite the bullet and order a couple EF86's but I'll find a use for all those 6AU6's one day... that gain of 300's gotta be good for something.

[klingo]

http://www.valvewizard.co.uk/ again
the guy says pentodes are good CCS's(Constant Current Sinks) and that in this application we haven't to worry about noise or microphonic.
there's a interessing pentode "tail resistor" for schmidt PI in this link(go to Constant Current Sinks)
cheers

[Aharon]

Here's a link to the HWY 86..............this amp has been built and there's a report somewhere on the net.
6Au6 input and ECL86 PI and PA.

http://www.harmonicappliances.com/highw ... -86-a1.pdf
Aharon

[klingo]

HWY86
http://www.harmonicappliances.com/h86/a ... thread.pdf
http://www.harmonicappliances.com/highw ... -86-a1.pdf

[Aharon]

Thanks klingo,like a dummy I forgot the link,all fixed now.
Aharon

[lastwinj]

i've been spouting off about the 6AU6 for about a year as a SMART alternative to the ef86.

its a great tube, built up an amp with one in the front end about 4 years ago. VERY nice sound.
no microphonics, either.

germ