Schu Posted January 23, 2015 Share Posted January 23, 2015 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted February 25, 2015 Share Posted February 25, 2015 Quote Link to comment Share on other sites More sharing options...
Schu Posted February 26, 2015 Share Posted February 26, 2015 Quote Link to comment Share on other sites More sharing options...
Max2 Posted February 26, 2015 Share Posted February 26, 2015 How to build your own tubes 1 Quote Link to comment Share on other sites More sharing options...
Fjd Posted March 13, 2015 Share Posted March 13, 2015 (edited) It seems to be the right time to get a picture of tubes actually glowing back on this thread. Many years ago there was an unusual class of tubes designed for the sweep circuits in tube-type TV sets that have substantially large reserve current capability; hence the name “sweep tubes” was coined. While sweep tubes are no longer made and some versions are getting much harder to find, there are examples that are still quite common. The sweep tubes can put out huge power levels and still have substantial reserve capability. Pete Millet’s Engineer’s amplifier [also known as a “Distortion-cancelling Push-Pull" (“DCPP”) amp], uses these unusual sweep tubes. Several years ago when Pete Millett started to sell PCBs with his DCPP circuit, George of DIY Audio Tubelab fame, decided to test the upper limits for power in relation to these sweep tubes. George used a power supply that would generate 650 volts at 1.7 amps and plugged in his samples of sweep tubes. The amplifier generated 250 WPC in this configuration with a 2,500 ohm load. Not satisfied, he decided to wire both channels in parallel through a common OPT set for 1,250 ohms and lo and behold; this combination generated 504 watts at 5% distortion and 525 watts at clipping. When I get time, I’ll post a few pictures of my Pete Millet DCPP amplifier to the Amp Porn thread. My DCPP amp is nowhere near George’s 504 WPC and only does the 20 WPC that Pete originally designed it for; and at that output, the sweep tubes will probably last a few life-times at that abuse-rate. Edited March 13, 2015 by Fjd 3 Quote Link to comment Share on other sites More sharing options...
Bryant0086 Posted March 13, 2015 Share Posted March 13, 2015 Bryant 4 Quote Link to comment Share on other sites More sharing options...
seti Posted March 13, 2015 Share Posted March 13, 2015 Here is my favorite least favorite tube. It is a great driver tube but I just bought it NOS... Sporadically it produces the sound of 10,000 fingers down the chalkboard as 10,000 eagles screech in for their prey. Reverted back to my RCA and it was fine again LOL.... Terrible terrible sound but beautiful glow. 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted May 2, 2015 Share Posted May 2, 2015 Quote Link to comment Share on other sites More sharing options...
Fjd Posted July 29, 2015 Share Posted July 29, 2015 (edited) Glowing Emission Labs 45 mesh plate output tubes in a Dennis Had “Fire-Bottle” SET amplifier. . Edited July 29, 2015 by Fjd 2 Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted August 13, 2015 Author Share Posted August 13, 2015 SET bliss! 1 Quote Link to comment Share on other sites More sharing options...
oldtimer Posted August 14, 2015 Share Posted August 14, 2015 You guys seem to get off on low light pictures of vacuum tubes instead of beautifully lit hot chicks. It is disturbing, and weirdly nerdy. Carry on. 3 Quote Link to comment Share on other sites More sharing options...
Gorm Posted August 14, 2015 Share Posted August 14, 2015 Still have a thing for Sylvania 7591's. Very hard to find unfortunately. I have a quad of them from my old Fisher 500c. Probably should sell them as I have no need for them in my Mcintosh. Quote Link to comment Share on other sites More sharing options...
Schu Posted August 19, 2015 Share Posted August 19, 2015 Who builds this stuff??? 2 Quote Link to comment Share on other sites More sharing options...
Scotty H Posted August 28, 2015 Share Posted August 28, 2015 1 Quote Link to comment Share on other sites More sharing options...
Chrome Magnum Posted September 26, 2015 Share Posted September 26, 2015 Clean and tight as always! BTW, how closely do you need to match tubes that are running in parallel and what, if any is the downside if you don't? Quote Link to comment Share on other sites More sharing options...
Chrome Magnum Posted September 26, 2015 Share Posted September 26, 2015 Clean and tight as always! BTW, how closely do you have to match tubes that are running in parallel? Assuming there are problems with running unmatched tubes in parallel. There's gotta be...... right?..... Huh? Quote Link to comment Share on other sites More sharing options...
Chrome Magnum Posted September 26, 2015 Share Posted September 26, 2015 Hey look! Three posts in a row! Sorry folks, still getting used to this interweb whozitz. Quote Link to comment Share on other sites More sharing options...
joessportster Posted September 26, 2015 Share Posted September 26, 2015 (edited) Heres a cool little Headphone OTL Class A output made By Garage 1217, it has an LED under the tube that can be turned off if preferred, it can also be adjusted to multiple colors I like the green, It uses about any 9 pin 6 or 12 v, currently has the jjECC82 12au7 Edited September 26, 2015 by joessportster 1 Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted October 8, 2015 Author Share Posted October 8, 2015 I don't think I've posted this one before. While listening last night I couldn't resist taking a picture! Maynard 1 Quote Link to comment Share on other sites More sharing options...
Chrome Magnum Posted October 8, 2015 Share Posted October 8, 2015 Pretty! The more filaments the better. Makes me wish those metal tubes,,, weren't =] Thanks for the pic... Quote Link to comment Share on other sites More sharing options...
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