Earlier in the month, [Elliot Williams] quipped that it had been far too long since we saw a VFD-based amplifier build. Well, that dry spell is over. This week, [kodera2t] started showing off his design for a VFD headphone amp.
Here’s the thing, this isn’t using old surplus vacuum fluorescent displays. This is actually a new part. We first covered it about 18 months ago when Korg and Noritake announced the NuTube. It’s the VFD form factor you would find in old stereo and lab equipment, but housed in the familiar glass case is a triode specifically designed for that purpose.
Check out [kodera2t’s] video below where he walks through the schematic for his amplifier. Since making that video he has populated the boards and taken it for a spin — no video of that yet but we’re going to keep a watchful eye for a follow-up. Since these parts can be reliably sourced he’s even planning to sell it in his Tindie store. If you want to play around with this new tube that’s a pretty easy way to get the tube and support hardware all in one shot. This is not a hack, it’s being used for exactly what Korg and Noritake designed it to do, but we hope to see a few of these kits hacked for specific tastes in amp design. If you do that (or any other VFD hacking) we want to hear about it!
And now for the litany of non-traditional VFD amps we’ve grown to love. There is the Nixie amp where [Elliot] made the quip I mentioned above, here’s an old radio VFD amp project, in this one a VCR was the donor, and this from wayback that gives a great background on how this all works.
Remember how so many people got lost in the 60 and never came back?
Well I think they’re just starting to come back now.
It’s probably that all those crossways neural connections that psychedelics were meant to make, are rotting off with senility and they are remembering who they are….
… Either that or word of netflix got out to the offgrid communes and they’ve had to escape to check it out.
Funny you should mention psychedelics.
I was thinking psychedelic laser kaleidoscopes will be next maybe even as a projected sound visualization.
Alex, I’ll take artis anal bum covers for 800.
couldnt you get a nice howl if you loop the input to the output
I’m thrilled to see these devices finally becoming available. I’ve been following this project closely since they announced the devices, and was worried they were destined to be vaporware. Microwavemont has another video showing the finished result, and reports that the device runs on only ~50mA consumption, which is lower than I would have guessed, and makes it much more appealing.
Damn, 50mA and 30,000 hours, I think I’m wanting to see the rest of the data sheet… which I note wasn’t available as of the 2015 announcement, one turned up yet?
Meh, fuggedaboutit, at $50 each won’t be wanting to use ’em real soon.
if this is a tube “amplifier” what is the TL072 doing there?
“For driving headphone, some impedance converter is required and I simply added voltage follower. As a place holder, I used TL072 but in the real device I will use NJM8920 (MUSES8920), which is also very famous (in Japan only?) good operational amplifier.”
Very few ‘tube amps’ nowadays are free from silicon, but I see your point.
I’m guessing that it’s waaaay faster to ponk an OP AMP then to design and make a custom impedance matching transformer ;-)
No kidding, those suckers ain’t cheap!
Ahh yes indeed!
Even at low power audio transformers aren’t cheap. Also I would rather use a mosfet source follower than an opamp to lower the output impedance: quieter and cheaper.
Where can I order those nutubes? And are there any more complex tubes (pentodes?) planned?
I want to see one in action and I’m curious if I’ll be able to get this design either as a product or a kit.
Ah, he has a Tindie store and this is offered there :)