My view is that the best valves were made right at the end. The manufacturers were doing their best to keep the thing alive and, as they say, really "pushed the envelope".
So I would like, let me see; EL503, EL520, YL1071, but octal or at least noval., YL1150 and some of the others such as D3A, 437A and so on. And how about an E55L that could cope with more than just "battery" voltages!
I would also like to see (if possible) some of the advanced materials and manufacturing technology applied to producing EVEN better 7N7s and other earlier types (insert as required, 50, 45, 71A, United Electronics 945 etc.)
Of course I echo the earlier request for the Bendix line of valves. How about blending some of that know-how with some of the types we know and love?
And I would love a 7N7/6SN7 with µ of say 25 or 30 but with the same anode resistance (or better still less) and the same low distortion. And an ECC82 that actually had acceptable distortion figures would be welcome too.
7N7
So I would like, let me see; EL503, EL520, YL1071, but octal or at least noval., YL1150 and some of the others such as D3A, 437A and so on. And how about an E55L that could cope with more than just "battery" voltages!
I would also like to see (if possible) some of the advanced materials and manufacturing technology applied to producing EVEN better 7N7s and other earlier types (insert as required, 50, 45, 71A, United Electronics 945 etc.)
Of course I echo the earlier request for the Bendix line of valves. How about blending some of that know-how with some of the types we know and love?
And I would love a 7N7/6SN7 with µ of say 25 or 30 but with the same anode resistance (or better still less) and the same low distortion. And an ECC82 that actually had acceptable distortion figures would be welcome too.
7N7
Now you've got me scratching my head, please explain that one.
edit: Humm, lemme see. With under 200v in triode mode a Gm of 50,000 isn't shabby. Anyone that likes WE 437A's should try this one. The only caveat is the weirdo socket. I've been getting them from the old Tek "3" series plug-ins that nobody wants anymore.
HollowState said:
It was just a little bit of hyperbole.
I know several people who like me, have bought these valves and have then wondered what to do with them. Yes gm of 50 is excellent and Pa is 10W, an unusual combination but one cannot swing lots of volts on them because of the low limits.
I blew up two of them, triode-strapped running just below their rated voltages and decided that apart from a limited-swing cathode follower or perhaps a headphone amp, there is little if any use for them in audio. As pentodes, their distortion performance is not very nice.
In any case there are other pentodes that give excellent gm that are not nearly so temperamental - E810F, D3A, E282F.
The B9G sockets were quite easy to find in England a couple of years ago.
7N7
Klimon said:
Yes, they would do for that, but when I was building I always eschewed inter-stage transformers, partly for cost and partly for aesthetic reasons - glass always looks better than iron.
Buty why would one need a 10W Pa valve to drive an interstage transformer? As I remarked above, there are plenty of valves with good gm (and therefore, low Ra).
7N7
Klimon said:
You already pointed out sthe aesthetics factorRp is still halve of 6s45 and you don't really have to chase 10 watts through them. Did I mention they look really nice?
Simon
Oh yes, they look nice all right - very meaty in fact - and especially when there is a fireworks display inside!!
And the anode resistance will not be 600 ohms unless you run them close to Pa max.
The best performer in this regard is probably D3A. From the data sheet I see that dissipating just 3.84W whilst triode-strapped, D3A offers 41mA/V. Ra at this point is 1.9k but, D3A's mu is over 80! And what about my favourite, E282F ? Dissipating 5W, E282F offers mu of 25.5 and Ra of 800 ohms.
D3A (and E810F) are especially good because they offer excellent gm at relatively low anode currents; I think that 15 - 20mA is usually enough to get them to deliver useful gm.
7N7
Mandolin,
The objective here is not so much to fantasize as it is an attempt to create a marketplace reality. My own suspicion is that all the audio mags, electronics mags, tube dealers, and tube manufacturers routinely check out this website. If there is sufficient demand for a device, it will be manufactured. My own sense is that 01A is the most likely candidate by virtue of the fact that it sell in multiple markets. I know that it was basically the only tube for 1920's era radios. Experimenters here would probably buy gobs of the things for their line-level preamps. Perhaps the guitar crowd might like the sounds created by a highly microphonic DHT. BTW I dig the 8417 idea.
The objective here is not so much to fantasize as it is an attempt to create a marketplace reality. My own suspicion is that all the audio mags, electronics mags, tube dealers, and tube manufacturers routinely check out this website. If there is sufficient demand for a device, it will be manufactured. My own sense is that 01A is the most likely candidate by virtue of the fact that it sell in multiple markets. I know that it was basically the only tube for 1920's era radios. Experimenters here would probably buy gobs of the things for their line-level preamps. Perhaps the guitar crowd might like the sounds created by a highly microphonic DHT. BTW I dig the 8417 idea.
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