One More Time: "True Mono" Carts vs. Mono Buttons/Y-Cables

Discussion in 'Audio Hardware' started by 2xUeL, Oct 4, 2013.

Thread Status:
Not open for further replies.
  1. Don Hills

    Don Hills Forum Resident

    A stereo cartridge has 2 coils, mounted at 90 degrees to each other, and the assembly tilted at 45 degrees to the vertical.
    A dual-coil mono cartridge has 2 coils, mounted in the same plane, and the assembly mounted vertically.
    A single-coil mono cartridge has one coil (of course), mounted vertically.
    The point of a dual-coil mono cartridge is for wiring compatability and galvanic isolation between the two input channels of the preamp.
    (If you're being pedantic, substitute "set of coils" for each occurrence of "coil" above.)

    Someone mentioned vertical stylus movement on a worn mono disc. Vertical movement occurs on all mono discs. It is caused by the "pinch effect", one of the causes of IGD.
     
    2xUeL likes this.
  2. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    New York, NY
    Don, thanks for jumping in! I looked up the meaning of galvanic isolation and it seems like it has something to do with preventing a ground loop--which makes perfect sense with what the Lyra engineer said about dual-coil mono carts preventing a "hum". :)

    So two questions:

    1. Does a manufacturer choosing a dual-coil mono design have something to do with them not having to completely redesign the inside of the cartridge or something?

    2. Even though they reduce or eliminate that potential for hum with a dual-coil design, are they technically getting more of a "vertical signal" than with a single-coil mono cart, as rl1856 had eluded to above?

    Thank you so much!
     
  3. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    New York, NY
    FTR, the following two tidbits of information seem to contradict each other. The first is from Lyra design engineer Johnathen Carr:

    (Note that Carr's comment is comparing a dual-coil mono cartridge with a stereo cartridge/mono button/Y-cable setup.)

    So are these dual-coil mono carts technically picking up a vertical signal (no matter how small) or aren't they?

    :confused:
     
  4. Steve Hoffman

    Steve Hoffman Your Host Your Host

    They are.

    Use the double Y. Be happy.
     
    Old Rusty and 2xUeL like this.
  5. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    New York, NY
    Mr. Hoffman,

    I have already done my comparisons and I am happy with a stereo cart paired with a mono button. I'm just a curious kind of person who likes to understand things, that's all...if you don't mind! ;)
     
  6. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    New York, NY
    And thank you for answering my question.
     
  7. Steve Hoffman

    Steve Hoffman Your Host Your Host

    It's like down - 25 or something, you can see it on a scope but you really can't hear it....
     
    2xUeL likes this.
  8. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    New York, NY
    Are you talking about a double-Y cable or a dual-coil mono cart
     
  9. Steve Hoffman

    Steve Hoffman Your Host Your Host

    Sorry, the cart. The vertical signal.
     
  10. action pact

    action pact Forum Resident

    In this respect, is there a difference between a dual-coil mono cart (ie: Grado) and summing the stereo channels via a mono button or double Y cable?
     
  11. Steve Hoffman

    Steve Hoffman Your Host Your Host

    Not to me.
     
    2xUeL likes this.
  12. Me neither. I'm telling y'all, the double 'Y-cable' trick is the shizznat. And sooooooo easy.
     
  13. action pact

    action pact Forum Resident

    That's what I thought...
     
  14. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    New York, NY
    I agree with you, but FTR, my intention with this thread was not to advocate for the double-Y cable strategy but to understand why I wasn't hearing a difference between that and the Grado MC+ (a dual-coil mono cart), and also to determine if it was even worth it to try a single-coil mono cart like the DL-102 (at this point, I may do it if I have the money just for proof, but at this point I'm guessing that I probably won't hear a difference).

    BTW: love the 2001 avatar ;)
     
  15. Steve Hoffman

    Steve Hoffman Your Host Your Host

    And remember, with the double Y, if you have a particularly problematic mono album with uneven groove wear just on one channel, you can pick the left or right (which ever is the quietest) and "double" that as well. Just let the other channel wire "dangle".

    All the comforts of a McIntosh 1965 preamp control that you can just unhook when not needed, all for 10 bucks.
     
  16. I like the $10 option!
     
  17. action pact

    action pact Forum Resident

    I wouldn't bother with the DL-102 unless you have a rather high mass tonearm. Your Technics arm probably can't bring out its best.
     
  18. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    New York, NY
    So what tonearms are higher mass, vintage ones or something?
     
  19. action pact

    action pact Forum Resident

    Yes! I'm talking old ESL, Empire, Gray, etc.
     
  20. McLover

    McLover Forum Resident

    Location:
    East TN
    Newer examples: Audio-Technica ATP 12-T and ATP 16-T, SAEC, Fidelity Research, Jelco.
     
  21. Don Hills

    Don Hills Forum Resident

    I used to have a preamp with an elaborate mode switch: L, R, L+R, Stereo, L/R Swap. Was the McIntosh something llike that?
     
  22. Steve Hoffman

    Steve Hoffman Your Host Your Host

    Yes, exactly. All good preamps had them in those days.
     
  23. 2xUeL

    2xUeL Forum Philosopher Thread Starter

    Location:
    New York, NY
    Thread revivial. This really was a great thread. I just revisited it for clarification on a couple things (this mono thing can be confusing!), and I now that I've reread everything I thought I'd summarize what I learned below:

    If you're playing vintage mono records on a modern stereo system......

    1. Using a stereo cartridge without summing the left and right channels at any point is by far the least desirable option. Vertical noise is panned hard left and hard right in the stereo spectrum and thus is much more noticeable, but it also is louder in relation to the music than in the other options below [this is partly due to its position in the stereo field and partly because the "side" signal level (stereo information/pure noise with a mono record) is greater in proportion to the "mid" signal (the actual music)].

    2. Using a "true" single-coil mono cart (like the Denon DL-102) should produce similar results to option 4 below, but there is potential for a ground hum when used in a stereo system (if you have a full mono system though, this is not the case).

    3. Using a stereo cart with a mono button or a "Y-cable" significantly attenuates vertical noise (now the "side" signal is lower in proportion to the "mid" signal) and aligns it with the audio signal so it is less audible and hence "masked" by the music.

    4. Using a mono cart with two coils each aligned to only pick up the horizontal signal of the groove (like most modern mono carts like the Grados and the Ortofons) seems like the optimum option with a stereo system, but in my own personal A/B tests I honestly could not perceive an audible difference between this and option 3 above. Technically speaking, in this configuration the coils present even less vertical noise than the summing in option 3 above (virtually none I suppose), but whether or not one can hear the difference is another story. Also, from what I have gathered, each coil in this configuration is aligned the same way as in the single coil configuration in option 2 above, but there is no chance for a ground loop when a dual-coil mono cart is used in a stereo system.

    If I've made any mistakes, please chime in. :)
     
    Old Rusty likes this.
  24. Sid Hartha

    Sid Hartha Well-Known Member

    Location:
    The Midwest
    Since the '70s, I've never been without a "summing to mono" solution for playing mono records. Can't imagine going without it.

    Currently, this is what I must go through to make it happen:

    [​IMG]
    Basically, it engages a low-noise summing amp via the receiver's tape monitor loop. One advantage to this is that I'm able to precisely channel balance the summed signal, as well as level match the output against the regular stereo signal. Another advantage is that it's just a tap of the remote - I like things to be easy.
     
    Last edited: Feb 16, 2014
    Old Rusty likes this.
  25. action pact

    action pact Forum Resident

    That sounds about right, except I'm reasonably certain that the Grado mono cartridges are no different from a stereo cartridge with the channels bridged. I once contacted Grado for confirmation and only got a vague response. Maybe someone here has more definitive information.
     
    Last edited: Feb 16, 2014
Thread Status:
Not open for further replies.

Share This Page