Opinions of driver tube models and a general query about EL-34 and KT-77s

[camtwister]

Fellows,

I'm researching a tube rolling exercise for my Primaluna Prologue Four power amp, which has adaptive autobias circuitry.

First, I have a general question. All things being equal (make and vintage etc.), what are your opinions on the sonic attributes of EL-34 versus KT-77 power valves in a PP amp?

Secondly, does anyone have any direct experience of comparing the Russian New Sensor Gold Lion 12AU7/12AX7 tubes with NOS Mullard 4003/4004? I understand that the Mullards are a 1960s tube with box plates. The re-issues and the Mullards are currently selling for a similar price. I'm curious about how they compare given the positive reviews I've read of both in isolation.

Thanks folks...

[Marco]

Hi Johnny,

If Anthony TD doesn't see this, please send him a PM, as he'll have pretty much all the info you need, and he lives in your neck of the woods, too! :)

Marco.

[camtwister]

Thanks Marco, I'll do that.

[Marco]

Please do, Johnny, as you'll find Anthony most helpful :)

Marco.

[tannoy man]

Hi Johnny. just wonderd if you bought your Meadowlark Shearwaters from Holden Hi Fi in Cardiff, I took a pair on home demo many years ago nice speaker.
Anyhow back to valves I recently bought a set of Siemens NOS EL34,s from Langrex and they are superb ,PM me if you want to hear them, as I also live in Cardiff.

[camtwister]

Thanks for the kind offer, Paul.

I bought the Hot Rod model version of the Meadowlarks, unseen and not auditioned, about a year ago, from the original purchaser in the home counties. One of the best gambles that I've taken, based on my liking of time coherent designs, first-order crossovers and transmission line cabinets. I really enjoy them.

Some reviews for those interested:
http://www.stereophile.com/floorloudspeakers/669

http://www.soundstage.com/revequip/ian03.htm

Anyhow, a little off topic now, so best move along...