6N1P Headphone Amp

[Cressy Snr]

Thanks Nick.

[Cressy Snr]

Have been doing a bit of tube rolling in the headphone amp and surprisingly, the best sounding valve is the Russian 6N23P.
It beats Mullards, Philips Miniwatt, GE 7308 and RCA 6DJ8. Don't know how 6N23P would fare against Amperex Bugle Boy or Siemens CCa, but I can't afford those anyway.
The 6N23P has a very nice extended treble that complements the extension of the Sowter OPTs. The 6N23P are Voskhod, with the rocket logo and go for £150 for a matched pair on Langrex. I didn't pay anywhere near that when I got them years ago.
They are also very low noise.
I'm well pleased with this headphone amp now I've got it quiet.

[Ali Tait]

I've found the same. I've a good few NOS Mullards etc, but having read about early 70's 6n23p I bought some to try in my Graaf preamp. They're better than any others I have.

[Paul Barker]

Every day a school day. I have no issues with my Mullards in my EL38 amplifier. But I suppose it’s over sensitivity to noise in hpa.
Edit, single Mullard. One valve covers both channels as I used all the surplus voltage to resistance load the anode’s. Which also allows both the VA and the output valve to share the same ripple voltage, which as was mentioned in the Jeremy Epstein article in Sound Practices results in low noise. Not that I am saying that may have worked for you.

[Cressy Snr]

Wouldn't have worked for me as I only have a single stage of amplification.

Glad Ali found the same as me with the Soviet valves.

[Ali Tait]

Apparently the early '70's single wire getter version is the one to have. They certainly sound good!