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72 phono boards

Discussion in 'audio' started by worz, Mar 26, 2020.

  1. worz

    worz pfm Member

    Hi all being isolating and playing around with my phono boards. I'm running a dynavector 10x and really struggling to get a satisfactory sound with my n boards so swapping to s boards wow much better in terms of what I'm after
    Now I can hear I not quite right as they are for low output coil but i prefer them ,are the e boards the inbetween I need
    Regards
     
  2. nobeone

    nobeone pfm Member

    N are Moving Magnet cards, S are as you say low output Moving Coil, K are low output MC for Linn cartridges (Karma, Troika etc). E are like hens teeth I would imagine, I think they were originally for Roksan Shiraz, a higher output MC, might be the closest match for a DV 10x?
     
  3. nobeone

    nobeone pfm Member

    Might be better off seeking out somebody that still makes 72 phono cards, RSL or Neil Jadman spring to mind. Alternatively it may be it is easy enough to make E from S/K which are the same except for a simple R and a C swapped, though I have to say I don't know it is that simple for Es!
     
  4. sq225917

    sq225917 situation engineer

    The mc cards differ in the c and r on the input. Buy some metal film resistors and have at it. Leave the c alone its there to slug rfi.
     
  5. YNWOAN

    YNWOAN 100% Analogue

    The Ryan Sound Labs boards offer adjustable resistive loading with a little plug in module that attaches to the boards - very easy to change.
     
  6. nobeone

    nobeone pfm Member

    No I don't think this is true for E. It is the case for S and K though! Check out this pfm post where the difference is explained.

    EDIT: and this post with a walk through of modification of S to E
     
  7. worz

    worz pfm Member

    Thank lads unfortunately I'm not able to do the DIY job, I was wondering if someone like class A would do it
     
  8. nobeone

    nobeone pfm Member

    I would think Class A or Witch Hat would be the obvious choices to change an S to E.
     
  9. Craig B

    Craig B Re:trophile

    IME, when running HOMC into LOMC inputs, there exists an unnatural 'fuller' sound due to complimentary compression affects. Turning the wick up higher into MM inputs generally sounds best.
    There are two electrical factors at play here; input sensitivity, and impedance.
    DV-10x5 output voltage is 2.5mV (@ 1kHz, 5cm/sec, 2.8mV for 10x5 MkII) with >1kOhm input impedance recommended, a good match for the 2mV input sensitivity, and 47kOhms input impedance of N boards.
    Naim's MC boards range from 100uV (S & K) to 400uV (E) sensitivity with 560 Ohm impedance; therefore DV10x5 output is 25 times higher than S and K input sensitivity and 6.25 times that of E; in addition, the input impedance is too low.
    IOWs, if one has N boards already, there is no need to attempt to create such from S, K, or E.
     
    nobeone likes this.
  10. worz

    worz pfm Member

    Yes it is fuller I just find the n so undynamic and insipid, maybe time for a stand alone stage
     
  11. Mr Pig

    Mr Pig ^'- -'^

    I found even a modest external stage to beat internal ones. Don't know why, but they do.
     
  12. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    100% wrong. And I design, build and sell external phono stages! (all types in fact. In trade sales, where maybe a person and one dog may see it, is a thread showing a conversion I did to add MM phono to an MC Exposure pre recently).

    Manufacturers will obviously save their best phono stage designs for use as external ones. Most will not want to pay say £3000 for an integrated amp in which £2000 of it is for an all singing all dancing phono stage!

    At lower prices though there is little to choose between them.

    Naim phono cards are easily beaten but it's nothing to do with them being inside a pre amp.

    In fact, if done with due care and an external power supply an integrated amp with built in phono has advantages in theory as all aspects of the grounding, connections between, "impedance matching", gain structure and screening of the unit as a whole can be specified and controlled.
     
  13. YNWOAN

    YNWOAN 100% Analogue

    I agree, though I would go further and say that many phonostages up to £1K are just different flavours of the same overall standard (and some costing more than that).
     
  14. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    What I meant was between built in phono stages and separate external ones. I disagree that stages up to £1K+ are all much the same! What I will say is that there is often no real difference in the complication or value of components between some £300 stages and some £1000 ones....
     
  15. RyanSoundLab

    RyanSoundLab Trade: Ryan Sound Lab

    If you'd like to try the RSL MM boards, please send me a PM. There are loaner sets in the UK and US right now that can be tried on your own system.
     
  16. worz

    worz pfm Member

    Hi all thanks for replying and help, I do have a audiotechnica 07 low output cart to try into a boards when I can get some longer bolts .
    I will take it from there as the s boards do seem very musical ,I will report back with my findings
    Cheers Martin
     
  17. joe9407

    joe9407 actress/activist

    I found exactly this when using a 10x5 into the Stageline N. The S boards are regarded by many as the better match. Stupidly, I had the 10x5 and a "souped up" Stageline S at the same time a few years ago and never tried the combination.

    I eventually bought a DV P75 phono and it was much better with the 10x5.
     
  18. TimF

    TimF pfm Member

    Damn, there for a second I had thought Trump had stepped into PFM and started to comment on phono stages!
     
  19. worz

    worz pfm Member

    Just abit more on my experience with naim boards. I've been plodding on with the S boards and they are really very good ,alot more gain and full in sound the complete opposite to N .
    I have been in contact with class a and they can convert s to e at a reasonable price so am going down that route, hopefully giving me the best of both words
    Regard
     
  20. Craig B

    Craig B Re:trophile

    Sounds like a good idea.

    As bonus, running a cartridge with 'only' 6.25x the sensitivity of the phono input (rather than 25x, as with 'S'), should improve the volume control range before running the amp into clipping.
     
    Last edited: Apr 1, 2020 at 4:02 AM

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