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What to do with 6DJ8 tubes?

I received a pair of Amperex 6DJ8/6922 gold-pin tubes, and I've been perusing the web looking for something to do with them.
Obviously, I would be a preamp/head-amp usage preference, as I prefer the sand in my output stage. I'm also not totally tube-amp-literate.

So far, I've found the OddWatt head-amp project, and some Schiit preamps that could use them. What I'd like is something that would not tax them heavily. Apparently, they are sought after and EXPENSIVE. I'd like to use their attributes indefinitely in a DIY project if I go there. I'm intrigued by maybe a FET output stage or something along those lines.

What say you?

Comments

  • Don't ask me, all I do is make smoke with em'.

  • edited May 2021

    I built that same basic circuit from the OddWatt 6DJ8 SRPP linestage years ago. It's a decent circuit and pretty simple, but not what I would call a design worthy of those nice tubes. At the price NOS Euro 6922s are going for, I would be inclined to sell them and buy some decent 6SN7s to build the Aikido linestage...or just build the solid state Wayne Colburn (Pass Labs designer) linestage kit.

  • Tom, great looking build. Thanks for helping all of us tube nubes.

  • Tom has been a great help to me.

  • I would highly suggest building the Aikido CF (cathode follower) linestage with those 6DJ8 tubes. I built that linestage preamp design, using a pair of 6DJ8 tubes Tom gave me, about 10 years ago and I listen to it almost every day.

    kenrhodes
  • Thanks guys - I'm not sure I deserve it. There are lots of guys who know so much more than I do when it comes to electronics & tubes.

    I know Andy, Bill, & Craig are also tube guys. I mentioned the 6SN7 Aikido circuit because Craig (and many, many others) have given it pretty high marks. Wolf, if you decide to go that route, I'll see if I have any parts in my stash that would work for you. I owe you at least that for all the bones you've thrown my way over the years when I had speaker questions.

  • I'll think it over, and look up the Aikido...

  • Ben,

    I can bring my 6DJ8 Aikido preamp to Indy next weekend if you want to give it a first hand (ear) listen before you commit to building something. Mine has single ended inputs and outputs with just RCA phono jacks. I should be there pretty early Friday afternoon... you could bring your tubes and hear how they sound on your own speakers.

  • That sounds like a great idea! Please do! I'll bring the tubes...

  • One more thing- Am I supposed to handle the glass, or are gloves really a good idea? I know headlights/lamps should not have body oils on them. Just making sure it's okay...

  • IMO the Aikido circuit topology is absolutely brilliant due to the power supply noise rejection. However, you need to ask yourself a few important questions before you go down the vacuum tube rabbit hole:

    1: Do I need a preamp with gain? And if so how much gain? Some pro amps need a higher level drive input. Otherwise is just a unity gain line stage ok?
    2: Do I need to drive a difficult load or long cables to the power amp?
    3. Do I just want to have some kick butt looking glowing tubes in my system? Kind of a joke question but I believe some folks do use tubes for that simple reason.

  • If you do need the gain I would su> @Wolf said:

    One more thing- Am I supposed to handle the glass, or are gloves really a good idea? I know headlights/lamps should not have body oils on them. Just making sure it's okay...

    Vacuum tubes, especially the older ones, are tough beasts. No concerns about handling them with bare bands.

  • Ben - be careful handling those, but not due to the oils. The ink the used on some of those Euro tubes is prone to smearing. That can take a big hit on the resale value.

  • Craig - I have so many circuits floating around in my head, I forgot your Aikido used 6DJ8s. What did you build that runs the xSN7s?

  • I built the GlassWare (tubecad) CCDA circuit with the xSN7's. It sounds really good and has enough (not too much) gain. However I think the Aikido cathode follower with the 6DJ8's sounds the best. Maybe someday I'll build another Aikido CF that uses the xSN7's.

  • I built mine old school with point-to-point wiring, i.e. no printed circuit board. I think I drew up my schematic on my work computer with my exact circuit and component values. I'll look for that tomorrow and post it. Mine has a regulated 12.6 VDC supply that I can flip a DTDP toggle switch for either two 12SN7 tube filaments in parallel or for two 6SN7 tube filaments in series. It also has a completely overkill B+ supply that has a CLCRCRC filter. Hey... it's DIY so no limits, right?

  • Has anyone done business with glass-ware? Sent them an email many days ago about some of their boards but yet to get a response. Wondering it they are still open?

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