• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

6FW5-6AV5 PP tube amplifier

Jump to Latest
kuly

kuly

Member
Joined 2012
kdsdostup.wixsite.com/sarts
#1
Hi!! Who can share the scheme? Tube amplbfier PP 6FW5
ideal innovation ELITE 40!!I can't find on the Internet!
 

Attachments

  • Unknown.jpeg
    Unknown.jpeg
    7.1 KB · Views: 173
#3
^^^^
Yeah, I'd like to see that myself.
We really like the performance and sound quality of the Philips-ECG-Sylvania 6AV5GA that we use in the Elite80, Elite40M and Elite40SE amplifiers. From info we have gathered these are actually an upgraded military version of 6FW5's labeled as 6AV5GA's. The 6FW5 is a much heavier dissipation tube than your standard 6AV5GA. This heavy duty version of the 6AV5GA also has the top getter which silvers uniformly only the top portion of the envelope, making the tube's appearance also very cool looking. This 6AV5GA is a very well manufactured tube, made in the USA, by Sylvania in Emporium, PA in 1984. They are a very robust design with cathodes larger than a KT88’s. Originally made for demanding military applications these ideal power tubes provide unrivalled sonic performance in the correct audio circuit, at least in our opinion, and we believe yours too once you listen with this amp.

So several years back we did some R&D of our own just to see what could be done with these things. We found a small stash of these Philips-ECG (Sylvania) 6AV5GA’s and got busy in the lab. And with a good number of hours and a number of circuits later we began to see - actually hear - what this deflection tube hype was all about.

Operating these output tubes modestly as we do makes an amplifier that not only sounds very nice, but will also last a long, long time. In fact we have recently had the opportunity to inspect and upgrade one of the first Elite80's we built, and with well over 5000 (now reported at over 10,000 hours) hours of reported running time on these Sylvania 6AV5GA's there was no sign of sonic degradation, so we sent it home with the original tubes still going strong!! If you look around on the web you’ll find an ever expanding, near cult, listener following of horizontal sweep tubes and interest seems to be spreading.

To make a long story short, these particular deflection tubes are SIMPLY AMAZING. In our Elite80, Elite40M & Elite40SE amplifiers they display everything one wants in full range clean music reproduction. We have since secured a large number (actually 1000's) of these NOS premium quality 6AV5GA’s so there's no need to worry about the supply. We have the ability to maintain and support your investment for years. In our opinion there has never been a better made 6AV5GA/6FW5 tube.
Click to expand...
The 6AV5GA is very close to the 6BQ6GA/GTB, and is basically a "6BQ6" without the plate cap. They say they began their R&D "several years back". I did mine in Ought 7 -- a design that used the 6BQ6GA/GTB after seeing an article from QST describing a 25W AM plate modulator that used this type. I thought that strange, seeing how you'd expect to see 6L6s for this power class. After running some loadlines, it became clear why they did it. Listening tests without NFB confirmed: none of that pentode nastiness until almost clipping. Most of the residual from the Twin-T test showed h3 mainly (nearly undistorted sine wave at 3X the test frequency, unlike the nearly sawtooth residual from the 807s). The raw sound is overly "aggressive", and so needs some NFB to take the edge off.

"If you look around on the web you’ll find an ever expanding, near cult, listener following of horizontal sweep tubes and interest seems to be spreading" I did a lot of talking up the TVHD finals back in Ought 7 when 6BQ6GAs were a buck a pop. It wasn't very long before the prices began creeping up. I'd like to see how the schemo of these "Elite" amps compares to Le Renard. I'm beginning to get that ripped off vibe again.
 
#5
^^^^

" I don't see the point in wasting money on expensive lamps". Neither do I.

"I listened to several horizontal scan tubes for a TV set in triode mode!" How'd that work out? The one difficulty with TVHD's is the low screen voltage that results from having the screens so close to the cathode. Not busting the screen voltage spec doesn't make for very much power (although some, like the 6AV5 don't seem to mind over volting the screen for triode operation. As for other types, YMMV). I designed for 6BQ6s operating as pentodes with active screen voltage regulation.
 
You must log in or register to reply here.
Top Bottom