I really like the 6CG7/6FQ7 in my UFOs as well. My favorite is the RCA black plate, ahead of the clear top and Raytheon/Matsushita, but they all sound good.

Hi Fellas. Hope y’all had a good 4th!

I remember talk of this tube in the past. James, what are your current input tubes in your UFO’s, and how would the 6CG7 compare?

These are so inexpensive, it warrants investigation

Thanks Geno, my current input tubes are a bit spendy: Tesla 6CC42 pinched waist, crossed swords. They've been there for a while and aren't going anywhere. They sound big, fast and transparent. I would say in contrast the 6CG7 are big and bold, and trade some transparency for a little more warmth.

Yes, you can find 6CG7/6FQ7 (I forget the exact difference between them, but they are essentially the same tube) very inexpensively, esp. compared to "heritage" 6922/7308 types. The RCA black plate and clear top are borderline heritage themselves, and are more expensive. I got a really good deal on mine, lightly used, at the start of the pandemic. But I would call the type a best buy today so hurry before they get discovered .

FYI/FWIW the tubes are the 9 pin equivalent of the 6SN7 and are pin compatible with the 6922/6N1P input tubes in Decware amps.

You're very welcome, always happy to talk about tubes . Even if it means hijacking Lon's thread.

Quote:


Let me say one more thing about the 6CC42. On my actual UFOs they were good, but not really a shortlist favorite. For whatever reason on the UFO25s they are in fact very much a favorite, but of course JMO/YMMV and all that.

So yes, there are several different 6N3P types and before the war I bought a bunch of them for like a buck each (yeah, the good old days). And, in  a word, they all sucked except for the 6N3P-DR which was very good. There is also the GE 5670 which are also nice, esp. the 3 mica JAN.

Quote:


I have wondered exactly the same thing, and I have no answers. I'd speculate that the pinched waist were typically very early production (which is usually better) and maybe made with a little more TLC than when they were cranking out tubes by the millions. But it is worth remembering that in general audio was an after thought for these tubes and they were originally designed for radio (or later TV) transmission and reception or radar or electronic test equipment. So why some tubes "sound" better than others in general is another and perhaps unknowable mystery.

No worries, I don't feel anything has been hijacked here--and I like conversations that flow, even if they move elsewhere a bit.

To answer one question: I think, comparing tubes otherwise very similar, that "pinched waist" tubes tend to be less microphonic and perhaps a bit more 'focused.'

Quote:


Yep.

Quote:


I have not. I wonder if they are actually another maker rebranded GE.

Well, I'll soon have two RCA black plate 6CG7 to roll but in the meantime I went through about seven pairs of driver tubes and settled into probably the most unusual: a pair of Amperex 6085 used without the converter bases. As I guessed and Steve has told me these should NOT work in the Monoblocks I had before, and did, and do work here. And the sound is detailed and the soundstage is deep and a tiny bit of "forwardness" that the Sylvania 6CG7 pair had is gone. Listening to Keith Jarrett play nearly fifty years ago and the piano sound is vivid and quite realistic. Happy camper! Tuesday or so the RCA should arrive. They will have a hard time besting the sound of these 6085.