tube buffer for record-out on Fisher?

Discussion in 'Fisher' started by beatcomber, Apr 2, 2018.

  1. beatcomber

    beatcomber AK Member

    Messages:
    17,929
    Location:
    Lexington, Massachusetts
    I'd like to be able to use my Fisher X-100 for needledropping vinyl, but my Tascam DR-40 recorder messes up the impedance and causes the output to drop significantly. The recorded results are also underwhelming.

    I've heard that inserting a tube buffer between the amp and recorder will fix the problem. Would this be a good choice or should I aim higher?
    https://www.amazon.com/Dilvpoetry-T...F8&qid=1522680176&sr=1-7&keywords=tube+buffer
     

     

    Please register to disable this ad.

  2. nj pheonix

    nj pheonix AK Subscriber Subscriber

    Messages:
    9,732
    Location:
    New Jersey
    I know some use an internal OP amp for just that purpose
     
  3. beatcomber

    beatcomber AK Member

    Messages:
    17,929
    Location:
    Lexington, Massachusetts
    I'm not sure what you mean... I'm not savvy about tinkering inside amps.
     
  4. nj pheonix

    nj pheonix AK Subscriber Subscriber

    Messages:
    9,732
    Location:
    New Jersey
    I'll see if i can find you the thread. If your not into tinkering it may not be for you anyway.
     
  5. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    36,447
    Location:
    Southern NJ
    You could build it external for use off battery power too. I think it was in Dave's gilded 202 thread.
     
  6. beatcomber

    beatcomber AK Member

    Messages:
    17,929
    Location:
    Lexington, Massachusetts
    I appreciate the replies, but it sounds like too much of a project for my ability.

    So, a $30 tube buffer isn't recommended?
     

     

    Please register to disable this ad.

  7. nj pheonix

    nj pheonix AK Subscriber Subscriber

    Messages:
    9,732
    Location:
    New Jersey
    Best answer I can give you is I don't know.
    I've never seen or used one. It might do exactly what you want but at this point , your guess is as good as mine
     
  8. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    36,447
    Location:
    Southern NJ
    Whats the fun in buying stuff that works when you can have hours of frustration figuring out why something doesn't work right?

    Should be fine honestly. As long as it has high input impedance and low output impedance all is well. I just don't have any personal experience with commercial products, but if its a cathode follower like I expect it is, that will do the job fine. If I were building one to do that job, thats what I'd construct anyway.
     
    beatcomber and nj pheonix like this.
  9. beatcomber

    beatcomber AK Member

    Messages:
    17,929
    Location:
    Lexington, Massachusetts
    I pulled the trigger, using some points on my Amazon Visa. I'll let you know how it works out!

    Actually, I bought the one branded FX-AUDIO because the brand name is less silly and it's available with a silver face:

    [​IMG]

    Internally they look almost identical, except for the circular wiry thingy.

    FX-AUDIO:

    [​IMG]

    Dilvpoetry:

    [​IMG]
     
  10. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    36,447
    Location:
    Southern NJ
    Fair bet those things all come out of the same factory anyway. Maybe slightly different options depending on the label. The wire thing is a choke, most likely being used as a power supply filter. If this runs off a wall-wart, it probably steps up the voltage inside, and the choke filters out the switching hash from that process.
     
    beatcomber likes this.
  11. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    21,765
    Location:
    Glen Burnie Md.
    Wait a minute. These tube buffers won't do that as they are designed to go from either a phonograph or solid state to tube.Which IIRC is Low to HIGH impedance. Going the other way if you hook it up as it's designed, it'll really screwup your recordings. I'd suggest you build or have built the buffer that DaveGillespie designed to go into the 400 when the Space expander jacks are re-designated asPRE-OUT to MAIN IN Jacks. It allows the 400 to be used with S.S. Amps with no degradation ofsignal or sound. It would have to be built with a power supply so you'd need to design one.
    It's fairly late in the thread so some readingis necessary.
    http://audiokarma.org/forums/index.php?threads/improving-the-fisher-400.511867/
     

     

    Please register to disable this ad.

  12. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    36,447
    Location:
    Southern NJ
    Low impedance sources can feed a high impedance input with no problem. Its the other way round that you have problems. It really wouldn't make any sense to convert a low impedance source to a high impedance one. It would be a little difficult to do with a tube at zero gain anyway. I'm sure you could bodge together some horrible circuit to make it happen but why anyone would want to is a mystery.
     
  13. nj pheonix

    nj pheonix AK Subscriber Subscriber

    Messages:
    9,732
    Location:
    New Jersey
    Yeah,
    Unless I'm missing something, I think the OP has it right.
    Also I'm sure the thread Larry referenced is the one I was thinking of .
     
  14. beatcomber

    beatcomber AK Member

    Messages:
    17,929
    Location:
    Lexington, Massachusetts
    Well, if it doesn't work as I hope, I can always ship it back for a refund, or find some other use for it.
     
  15. beatcomber

    beatcomber AK Member

    Messages:
    17,929
    Location:
    Lexington, Massachusetts
    I'm happy to say that the tube buffer worked as hoped, and I was able to get some nice-sounding needledrops!

    I'll probably spend another $20 to upgrade the tubes to NOS GE's, but it sounds pretty good with the stock tubes.
     
  16. nj pheonix

    nj pheonix AK Subscriber Subscriber

    Messages:
    9,732
    Location:
    New Jersey

     

    Please register to disable this ad.

  17. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    36,447
    Location:
    Southern NJ
    If that operates like I figure it should, it ought to be relatively insensitive to tube selection so I wouldn't worry about getting anything exotic for it.
     
  18. beatcomber

    beatcomber AK Member

    Messages:
    17,929
    Location:
    Lexington, Massachusetts
    Good to know, thanks!
     
  19. Patrice B

    Patrice B AK Subscriber Subscriber

    Messages:
    2,202
    Location:
    Montréal, Canada
    Bought a Yaqin tube buffer several years ago for the same reason: going from tape out of my X-100-2 to a SS mixer.
     

Share This Page