I was about to mention the EL156 in pentode, but see someone beat me to it.
I built an Shuguang EL156 ULSE amp with 450V on the plate, but never measured the output. It is an easy tube to drive - I used an EF86 in pentode. Plenty of power to run a pair of UREI 813A speakers.
http://www.mif.pg.gda.pl/homepages/frank/sheets/128/e/EL156.pdf
I built an Shuguang EL156 ULSE amp with 450V on the plate, but never measured the output. It is an easy tube to drive - I used an EF86 in pentode. Plenty of power to run a pair of UREI 813A speakers.
http://www.mif.pg.gda.pl/homepages/frank/sheets/128/e/EL156.pdf
I don't think EL156 with input step-up transformer will work well unless one has a beefy and mighty source. It's not a real solution, it's just shifting the problem from the driver to the source and usually it's just asking for more troubles......
It's that step-up the main problem.
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It's that step-up the main problem.
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Yes, I like this concept - only 1 element, but 2300V - is extremely high. At the moment I try to find something less energetic. But all other single tube variants are around 2W output.
Nearly 20 years ago John Atwater (of one-electron fame) had an SE shoot-out at his home in San Jose. The max power for most of the entries was on the order of 3W...But for the finale I set up my '13 Cubed' SE amplifier. 813's running into custom Doc Hoyer OPT's; 1300V on the plates and 2x SIXTY FIVE WATTS (130 watts total). Of course to spite the narrow minded group; the amplifier was all pentode; drive tubes were EF86's running 6AU5 cathode followers. The amps blew everything into the weeds with their premium OPT's and great circuit design. Later, Svetlana came out with the SV572 triodes. These beauties were good for well over 20 watts; the higher mu ones could easily do over 25 watts. Again, Doc Hoyer came up woth the output iron. I built several of these and sold them to fellow audiophiles.
WOW, this GM70 amp had a triple secondary output transformer!!... Very impresive, I wonder how it sound??
Any chance did you know the price of this GM70 Integrated?? ("МикроГМка")
http://spbsound.narod.ru/SPbSound/photo/photo7.html
Thanks
My that's some coincidence. I just built a GM-70 amp. Insanely nice tube. And very cheap. That's a hammond 18v 5 amp trans for it's filament supply. Ya 60 watts for the filament. It's just like a light bulb. This is my first iteration. Just using a Hammond 300-0-300 transformer gives me 810v on the plate. The power supply is designed for max 1200v though. I will switch in a 400-0-400v Hammond after some more testing. Should get about 1050v on the plate. I'm stopping there.
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No no no! That will just reflect the heat back to the tube's plate! The endbell won't be hurt by a little heat.
It depends on how much is "Little". And how "cheap" is transformer for such an amp.
Sure, I see now how far it is, how anode is oriented, and how shiny is the bell itself.
Is this tube capable of what you are asking? Maybe it requires a driver stage?
www.thetubestore.com - 6C33C-B Audio Tubes
I was once looking for the same thing. There's a Glass Audio article by Erno Borbely out there for a 15w SE with this tube, but I believe it's two stage. I have it if you'd like a copy.
PM me, if interested.
Vince
www.thetubestore.com - 6C33C-B Audio Tubes
I was once looking for the same thing. There's a Glass Audio article by Erno Borbely out there for a 15w SE with this tube, but I believe it's two stage. I have it if you'd like a copy.
PM me, if interested.
Vince
QE08/200 is good tube for ~20W output power in single end topology (A1).
http://www.diyaudio.com/forums/tubes-valves/307511-qe08-200-d3a-se-classa-triode-connected.html
http://www.diyaudio.com/forums/tubes-valves/307511-qe08-200-d3a-se-classa-triode-connected.html
