Let's talk preamp kits

Discussion in 'Tube Audio' started by airtime, Oct 7, 2017.

  1. airtime

    airtime Super Member

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    I mainly use a Conrad Johnson Classic 2SE that I love. So this post isn't about "going up a level" but more like something else to try and play with.

    I was thinking a cheap preamp kit to add more tube like sound. Ok, let's not get into what the tube sound is. The CJ is EXTREMELY transparent and adds nor takes away anything - it does what a preamp should - preamp and burffer.

    What kits would you recommend in the $500 range.

    A kit using mainly the 12axt, no tone controls, simple, no 12AU7 or 6922, something that puts more "warmth" back into the equation.

    I would use this mainly for my newer gear like a NAD C275BEE. Which gives me listening fatigue after 20 minutes.
     
    Last edited: Oct 7, 2017
  2. petercapo

    petercapo Well-Known Member

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    One tube preamp kit that comes to mind in that price range is the Transcendent Sound Grounded Grid preamp. Unfortunately, by all accounts it would not be very likely to meet your sonic criteria. Why don't you want 12AU7? From what I have read, 12AU7 has a syrupy, tubey quality.

    Transcendent Sound has another preamp kit for a little more that uses 300B.

    There is also this: https://www.tubedepot.com/products/elekit-tu-8500-stereo-tube-preamplifier-kit

    You might also have a look at the Little Bear kits on ebay and Amazon.

    The tubes4hifi SP9 is around $750 for the kit, I believe.

    You might find Analog Metric an interesting place to browse: http://www.analogmetric.com/
    Analog Metric seems to have preamp kits: http://www.analogmetric.com/categor...0&price_min=0&price_max=0&filter_attr=&page=1

    There is also this: http://diyaudioprojects.com/Tubes/tubes.htm


    Edited for spelling.
     
    Last edited: Oct 7, 2017
  3. superjojo

    superjojo Active Member

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    If you cant listen to it, why don't you sell it?
     
  4. petercapo

    petercapo Well-Known Member

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  5. kward

    kward AK Subscriber Subscriber

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    Hmm. Not a full kit, but there's the Aikido octal preamp board.
     
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  6. BillWojo

    BillWojo AK Subscriber Subscriber

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    Tubes4hifi, I have the SP9 kit. If you do your own chassis you can get the board kit for a lot cheaper.
    Responds well to tube rolling and was a major upgrade to my system. Playing familiar music I hear details that I never knew where there.
    I have a Aikido Octal tube kit that I'm collecting parts for. I found a great deal on the SP9 and this got shelved. Maybe this winter I'll finish it and compare.
    Both the SP9 and the Aikido Octal have been compared to preamp's that cost in the 3 to 5K range. Great designs without the designer signature. Although both designers of the mentioned preamp's rate very highly in my book.

    BillWojo
     
    Last edited: Oct 8, 2017
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  7. mcdan

    mcdan Well-Known Member

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  8. gadget73

    gadget73 junk junkie Subscriber

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    Bottlehead stuff also might fit the bill, though they run 12au7 tubes. I have one sitting here that I fixed. Sounds nice, not super tubey though if thats what you're after.
     
  9. Lavane

    Lavane AK Subscriber Subscriber

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    Ive been using an Aikido preamp using RCA 12au7 clear tops and like it. I should try the octal version at some point. There is a clarity to this design that I really like.
     
  10. nerdorama

    nerdorama AK member Subscriber

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    A friend built an octal Aikido. It's very good sounding. Not sure I'd call it tubey in the traditional sense.
     
  11. crispycircuit

    crispycircuit AK Subscriber Subscriber

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    A PAS 2 or 3 has plenty of tube mojo. Do you need a phono stage?
     
  12. gadget73

    gadget73 junk junkie Subscriber

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    PAS2 in relatively stock form may not happily drive a solid state amp though.
     
  13. petercapo

    petercapo Well-Known Member

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    I didn’t mention the PAS in my list, because I’ve had the sense that airtime has sworn off it. Still, the description of what he seeks in post #1 does sound like a pretty good description of the PAS...

    With the tone controls bypassed, it may be able to do it. It would need some study: http://www.audioregenesis.com/documents/PAS Compatibility Issues.pdf
     
  14. crispycircuit

    crispycircuit AK Subscriber Subscriber

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    Yes, I would recommend changing the input resistors on any solid state amps to better match the high impedance. Or a tube buffer. But not to many people would use a solid state amp with a PAS. The company Sound Values that took over the Dynaco name & inventory had sold preamps like you want. Retrovert has one. They got very good reviews and show up used, would also be easy to swap parts, I think it has a cathode follower for low impedance. Maybe PAS boards with a tube buffer board for your own custom kit. In Audio Amature there was a great remake of the PAS circuit with a buffer and B+ regulator. Vorhis mod could be hand wired in to your custom chassis. All depends on how time and effort is available. This stuff can take over your life.
     
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  15. airtime

    airtime Super Member

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    I'm leaning towards a Bottlehead or a full PAS kit. Again, the purpose of this is to tinker. I'm not looking for the ultimate preamp.

    Bottlehead's middle name is tinker and the PAS is the most worked on preamp in history. But don't worry I'm not buying a vintage PAS. Only the kits and parts and build my own chassis. So around the holidays I'll decide between the two.
     
  16. Paully

    Paully AK Subscriber Subscriber

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    Bottlehead seems a lot less about tinkering than it used to. Their products, which I still buy and use, are certainly subject to parts upgrades and and maybe putting a choke in the power supply and that sort of thing so there is some level of tinkering. But their lines are much more developed than they used to be when people were installing filters, regulated power supplies, dual power supplies, etc... etc... A lot of the best stuff is already incorporated. I would still recommend them to anyone but I just don't get the hardcore tinkering vibe from the Foreplay I days anymore.
     
  17. airtime

    airtime Super Member

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    I had a Foreplay WAY back in the day. I nick named it "the humming bastard". Never got that thing to stop humming.
     
  18. Paully

    Paully AK Subscriber Subscriber

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    Yea, I remember some posts along those lines... I had a FPII that buzzed like a hive but we managed to fix the problem, I think with a reverse recovery spike filter or some odd name like that (speaking of tinkering). My FPIII was trouble free and my Bee Pree is an astounding preamp. I love it and honestly never even think about upgrading it.
     
  19. sfox52

    sfox52 AK Subscriber Subscriber

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    I still use a basic FP II and love it.
     
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  20. Paully

    Paully AK Subscriber Subscriber

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    I still have a heavily modified FPII and don't really plan on selling it.
     

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