Valves, Transistors, IC's and Components. Bench test techniques, Test Gear - Valve Testers, Scopes, CRT Testers, Bridges, Sig Gens, Pattern Gens, Workshop tours etc
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I was shown one of these the other day. It is a double triode - operates on Va = 10 V, Vf = 0.7 V but behaves a bit like an ECC88.
I had no idea that such things existed.
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It's fascinating but seriously low power- Pa max is 1.7mW. It also works in class A2 (positive grid bias) with an input resistance of about 200K.
It seems to be touted more as a "nice sounding distortion generator" than anything else. The characteristic curves look much like those for conventional triodes but at lower Va and much lower power.
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It is an interesting "development"- but more prosaically, might reflect that VFDs (one of my favourite display technologies and one of the last outposts of thermionics!) are a diminishing market and teensy-weensy triodes represents a relatively low-risk toe-in-the-water in a market that craves "toob sound". It's obviously based on existing VFD fabrication techniques and experimenters have been exploiting the triode nature of the devices for a long time. I put development in parentheses as I can't help thinking it simply represents where battery valves would have been in about the early/mid 'sixties if the transistor hadn't appeared. Indeed, I suspect that tiny valves/thermionic ICs were on quite a few drawing boards and development labs on both sides of the Cold War but we just didn't get the full story.
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turretslug wrote:It is an interesting "development"- but more prosaically, might reflect that VFDs (one of my favourite display technologies and one of the last outposts of thermionics!)
Snap! I love
VFDs - so elegant and attractive.
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Weird. I guess it's intended for some sort of guitar gear as it's made by Korg, maybe in a guitar pedal.
Never played about with VFD's. I intended to, having got one off an old video recorder, but I put it somewhere safe and havn't seen it since despite several searches.
Thanks for sharing John, I'll see if I can find anything more out.
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Not so long ago you could get a VFD from Maplins in a mixed bag of displays for £4.99. I think they may still have them, best to look in store rather than online as at least you get to pick the bag containing the display you want! I bought some to repair a VFD clock that I stupidly dropped and broke
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