@R Scott Ireland sir if you dont mind can you post impression about the difference of those tubes?
OK, here goes:
1. Telefunken - To my ears, these tubes render a balanced and accurate representation across all frequencies. They are definitely NOT bass heavy, but accurate (to me), and I love them for classical music. They made my LCD-3's sound better than any other tubes I've tried with the Pan Am and they were equally good with the HD 800's.
Summary - very accurate; a beautiful tube but not for bass-heads.
2. Cifte - Here are my listening notes with both the LCD-3 and HD 800 - "beautiful, lush (very lush and strong, detailed bass with the LCD-3's), warm overall sound; medium-wide soundstage";
They also did very well with Denon D7000's, although these phones are so dark anyway that the highs sometimes felt like they were missing a little when compared to the HD 800 and LCD-3 - this was subtle; the overall sound was excellent.
They did not do as well with the Beyer DT880's; for some reason the bass and mids were not balanced and the highs were overdone.
Audio-Technica phones are a perpetual mystery to me; sometimes they sounded very good with the Cifte's; other times not, and I have no explanation (must be me!). This also happens with other tubes and solid state amps. This is with AD900X, AD2000 and AD2000X.
Summary - very slightly warm; very euphonic and pleasing; need to pay attention to synergy with particular headphones (and sources too).
3. Russian tubes/Voskhods - These tubes have always, to me, added treble into the equation. They are not "tizzy", but they do emphasize the highs at the expense of the mids and lows, and sometimes they can seem a little harsh because of this. That said, I love them with certain setups. They work great with cans like the Denon D7000's which are dark by nature. The DT880's did better with these tubes and the Audio-Technica's did very well too.
Summary - Tubes with treble on steroids; can be fabulous with the right phones, but unbalanced with others.
4. Siemens - I actually can't find my notes for these, and I haven't listened to them in a long time, so I can't say too much, other than that I remember them as being pretty neutral, along the lines of the Telefunkens, but not as refined.
5. Mullards - I also listen to Mullards a good bit and they tend to be on the warmer side, but are very euphonic and lush with the right phones. The DT880's (600 ohm) came alive with these; here are my notes - " An interesting and unique soundscape, different from all other phones; not as much bass as I expected with the Mullards, but the mids are incredible; enough reason to keep these headphones even if they sounded lousy with everything else."
Strangely, the Audio-Technica's often sounded good with the Mullards as well. It's unusual that a dark tube (Mullard) and a bright tube (Russians) both make a headphone sound good. I'll chalk it off to the quirkiness of the AT phones that I have yet to figure out (as I said earlier).
Summary - Warm, lush tubes that helped to give the term "tube sound" its name. A must-have tube.
Why didn't you tell that Mullards change so much!
