The Technics SL-1200 GAE/G/GR general questions thread

Discussion in 'Audio Hardware' started by Halloween_Jack, Aug 1, 2018.

  1. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    IIRC, the test record you're using is known for poor channel separation. Just couldn't see how a conclusion could be drawn as to how much was in the record and how much was due to the cartridge.

    I've not measured a 33, of any flavor. Owned a PTG/II better than a decade ago.
     
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  2. NoBody99

    NoBody99 Forum Resident

    Location:
    WV
    @JP
    I did it using their method, one channel, flip lp and measure the same channel. Did it twice, consistent. Used +/- 1 octave around 1000 Hz.
    Even more confused...if possible. Lol
    Measure at pre out -15 dB ~ unity gain
    Phono amp out = pre-out, ~170 mV 1000 Hz


    [​IMG]
     
  3. Upstateaudio

    Upstateaudio Senior Member

    Location:
    Niskayuna, NY
    I use Silver Resolution Reference by Signal Cable. Happy with it.
     
  4. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    Yes. Didn’t mean to imply LCR didn’t matter.
     
  5. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    I’m still lost.
     
  6. NoBody99

    NoBody99 Forum Resident

    Location:
    WV
    The CBS test lp method:
    Measure right channel with right freq. tones.
    Use the 1000 Hz value as 0 dB.
    Convert the other frequencies to dB using the 1000 Hz base.
    They have a conversion chart when RIAA equalization is used.
    spec = chart value
    delta = difference between spec & measured

    Flip lp over to left tones and repeat, but do not change the measured channel (right) when playing the left channel tones.
    Use those values to compute crosstalk.

    If the right channel measured 166 mV when playing the right 1000 Hz tone and the right channel measured 23 mV when playing the left 1000 Hz tone, cross talk:
    = 20 log 23/166 = -17.2 dB
    Do that for each frequency.

    They have >20 frequencies. I only did +/- 1 octave around 1000 Hz since the AT33EV spec is rated at 1000 Hz.

    At unity gain it was ~170 mV and 23 mV, same as the phono amp output.
    Same ~ -18 dB
    Output ~ 0.3 mV x 40/(10 + 50) x 9 (SUT) x 80 (MM section) ~ 170 mV

    Either I'm missing something, the test lp is not good enough or the cartridge is bad?
     
  7. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    Which one?
     
  8. haz2000

    haz2000 Forum Resident

    Location:
    nowhere
    BJC are nice cables for the 1200g but the connecting plug is big like a pen**. This is once instance where smaller might be better.
     
    Last edited: Nov 24, 2022
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  9. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    Are you waiting for someone to comment on how stiff the LC-1 cable is?
     
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  10. NoBody99

    NoBody99 Forum Resident

    Location:
    WV
    I thought you knew, you mentioned it had had poor separation.
    CBS STR-100
     
  11. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    Just confirming.
     
  12. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    STR-100 vs. Ortofon.

    [​IMG]

    [​IMG]
     
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  13. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    Phase angle on the Ortofon is interesting. I'll need to think on that one.
     
  14. NoBody99

    NoBody99 Forum Resident

    Location:
    WV

    Thank you!
    CBS ~ -20.4 dB
    Ortofon ~ - 34.6 dB

    so if I'm at ~ -18 to -19 dB it appears I'm getting everything out of it?

    How did you measure those?
    Is it safe to say -18 on the CBS is ~ 32 dB the Ortofon?
     
  15. NoBody99

    NoBody99 Forum Resident

    Location:
    WV
    I see
    CBS 180
    Ortofon ~ 45 (?)

    edit +90
     
    Last edited: Nov 24, 2022
  16. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    Virtins Multi Instrument.

    If your cartridge crosstalk exceeds what the STR-100 can measure you've no way of knowing by how much.

    Ya
     
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  17. NoBody99

    NoBody99 Forum Resident

    Location:
    WV
    looks like I'm buying the Ortofon :)
     
  18. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    I said that backwards, but you get it.
     
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  19. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    @patient_ot is the Ortofon the best current available for crosstalk? It's not been a measurement that's interested me so I've not validated any records.
     
  20. NoBody99

    NoBody99 Forum Resident

    Location:
    WV
    Yep

    hypothetical
    If you measured a cartridge using the CBS and got -19 what would you expect using the Ortofon? Or is there no way of estimating/extrapolating?
    I guess you are saying the -18 might be real and be -18 on the Ortofon, no way to know until measured.
     
  21. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    No way to know. Something close to the ceiling of -20 (my measurements) is likely real, but beyond that no way to extrapolate.
     
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  22. NoBody99

    NoBody99 Forum Resident

    Location:
    WV
  23. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    Yes. I can't vouch for he other tracks on it. I know the sweep tracks are rather inaccurate. My want to wait for @patient_ot to chime in as I believe he may know which records are best for crosstalk. I've measured up to -38dB on my copy which will exceed most cartridge specs.
     
  24. patient_ot

    patient_ot Senior Member

    Location:
    USA
    It is the best that I know of. I got the tip from Thomas A. I think he tried several test LPs that were currently in print. Obviously you have to make sure the record is flat and not warped or off-center. I only use the Ortofon LP for crosstalk and the tracking tests. It's not really good for anything else.

    I use the Ortofon LP with Audacity. I know some folks have used it with a Fogzometer or O-scope. I don't use the multimeter method for crosstalk as it's too much of a PITA.

    NOTE: FWIW all of the AT carts I tested (no MC though) were in-spec or exceeded spec with the Ortofon crosstalk tests. Obviously there could be some sample to sample variation and even things like temperature when you do the test do have an effect.

    @needlestein has tested a plethora of carts using crosstalk tests and could probably tell you more about how to optimize this sort of test or see whether a cart is meeting spec or not.
     
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  25. JP

    JP Forum Resident

    Location:
    Brookfield, CT
    A recommendation from Thomas on test records is meaningful.
     
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