Thijs,
never got the icy touch of king Alcohol on my own shoulder, i am a classic "co-addict" which is a technical term for those having addicts among familiy and friends and unable to do what ought to be done: get rif of 'em. Today, i never would help an addict anymore until he comes to me, asking me unforced "help me get rid of the stuff and i already bought the handcuffs and here they are." Helping alcohol addicts I have tried to often and failed.
Malt whisky, what does one eat to it? Well, i would suggest the same as with Bordeaux, an excellent white wheat bread. Like the french do. Anything else spoils the gorgeous taste.
Pier,
Hello, it's nice to heard that your grand ma have a telenfunken.
Misunderstanding

"Grandma radio" is a common German term for old tube radios (open baffle, wood case) dunno what my grandma owned.
I would like to know about your amplifier, so tell me about your amps bernhard?
My power amp is a thoroughly differential pushpull amp. But as it is still in the design phase, i hesitate to tell details.
What is clear already: the amp willbe zero loop feedback and
the output stage is a differential pair of AD1 (with a constant current source in the cathode) driving a Tango XE-45-5.
My initial idea was based on the need to have three stages and to tuck two XO networks between the stages. System 1 of both E80CC was meant to form together a choke-loaded differential pair with CCS, each system 2 was meant to be a cathode follower used differentially, also with CCS as load. Beauty of this is that amplifying tube matching is easy, cathode follower tube matching is unneccessary anyway.
But with the Fertin, I need only one XO network now, so i might try out interstage transformer coupling and for this i would go with another tube choice. My preferred input tube would be a #56 and my preferred driver tube would be the 71A; the interstage trannie would be a Lundahl LL1635. Negotiable in this concept is the input tube; the #56 has comparatively high plate resistance and with transformer coupling, matching of the input's differential pair is not that critical so i may settle on a 5687, better on a 6900 althoug they have a bit of too much amplification.
Info preliminary; as soon as i have something running, i post a schematic.
I listened to several amplifiers having driver (small) power tubes as driver with atleast the sonic reputation as the output tube. Stunning amps, each of them, particularly in the long-term listenability and seducability and absence of listening fatigue. Sakuma-san is right, the driver tube is atleast as important as the output tube.
The AD1 is beyond any questioning, and so is the 71A.