Does Anyone Use the "Vinyl: Check" test record? Have Some Questions.

Discussion in 'Audio Hardware' started by captouch, Nov 29, 2022.

  1. captouch

    captouch Forum Resident Thread Starter

    Location:
    Bay Area, CA
    I finally got around to playing around with my Vinyl: Check test LP, and I have some questions. If it matters, I'm trying to use the Puffin as a measurement device for some of these tests.

    So far, I'm trying to understand the Crosstalk test.

    If anyone uses this test LP and wouldn't mind fielding some questions, let me know.

    Thanks.
     
  2. daytona600

    daytona600 Forum Resident

    Location:
    UK
    Mono & Stereo © 2022: Tacet Vinyl Check insights (monoandstereo.com)

    The spatial reproduction can never be better as was cut on the record. With some electronic help you can enlarge the
    space but the result is also that the phase characteristics of the reproduction deteriorate. So in listening you’ll be
    somewhat handicapped.
    The total output of a cartridge on one channel (and also the other) is the sum of the main signal and the crosstalk coming
    from the other channel. Usually the crosstalk is around - 30 dB. But at higher frequencies this crosstalk level gets higher,
    so the influence is also bigger. With a channel separation at 20 kHz of say 20 dB the result is that already 10% of the total
    output is crosstalk signal.
    The crosstalk signal practically always is not a sine wave but a peaky and distorted signal. This causes a harshness in the
    main signal of this channel because the total output is the original signal and the crosstalk together. So a higher channel
    separation at high frequencies contributes dramatically to clean sound. This leads to a higher resolution in replay
     
  3. YEX 750-1

    YEX 750-1 Long-winded Brother

    Location:
    Los Angeles, CA
    I used Vinyl:Check with the Puffin for a while; more recently I've been using the AP ultimate test LP. Functionally both are pretty similar for the basic tests.

    Before the Test functionality was released for the Puffin, I would use Track A4 "crosstalk" on Vinyl:Check by calculating the difference between the Left and Right signal levels on the Puffin on the fly. Now, mercifully, the Puffin calculates this for us.

    How I use the new Puffin "Azimuth" (crosstalk) test:

    1. Turn on the Azimuth test on the Puffin. It will show either Left +X or Right +X or something like that. Ignore the number until you play the test track.

    2. Drop the needle right before track A4, crosstalk. The German man will introduce "Teil 4 Übersprechen" and will play a signal in the left channel, with right channel silent. The Puffin reading will quickly ascend to "Left +25.0" (example - this number is whatever the left channel separation is and it will be fluctuating). Then the LP will play a signal in the right channel only; the Puffin will swing in the opposite direction to Right +25.0 (again, example). Higher readings mean higher channel separation/lower crosstalk. The closer L and R readings are to one another, the more accurate and even the physical azimuth.

    3. Adjust cart azimuth until Left and Right numbers are as close to equal as possible.

    Important to note that the channel separation will be limited by the channel separation inherent in the lacquer cut. I experienced some small variance between the Vinyl Check disc and the AP test disc. I got slightly higher crosstalk numbers with the AP.
     
    Ingenieur, AaronW and captouch like this.
  4. captouch

    captouch Forum Resident Thread Starter

    Location:
    Bay Area, CA
    Thanks, that's helpful. I'm currently getting something like 21.x dB when the left signal is playing and 35dB when the right signal is playing, so it seems some adjustment is required.

    If I'm getting a higher R signal, if I'm looking at the headshell head on (so stylus is closest to me and cart pins are furthest from me), do I do a slight twist clockwise?

    My tonearm has a set screw on the bottom. So my plan would be to loosen the set screw, twist very slightly in the proper direction (clockwise?), and test again. I'm assuming the amount of adjustment is really really small in most cases.

    Another question relates to the VTA tracking angle error test. They play two tones and supposedly if you hear a summation tone of 1kHz, you have some VTA error. I tried it with no mat, my usual mat, and with a double mat. It wasn't obvious to me if the summation tone was there on any of them. I probably don't quite know what to listen for.

    Finally, there's also the general question of the best sequence to adjust azimuth, anti-skating, and other adjustments. Seems to me they're interrelated, because if your anti-skating adjustment is off, it could lead to a stronger L or R signal in the azimuth test. Likewise if your azimuth is off, you might end up setting the wrong anti-skating level. The anti-skating test on the Vinyl: Check test LP tells you to adjust anti-skate until you hear distoration start in both channels at the same time.
     
  5. YEX 750-1

    YEX 750-1 Long-winded Brother

    Location:
    Los Angeles, CA
    Given the higher R signal, the cartridge needs to be rotated slightly counter clockwise; the image below illustrates the physical situation, looking at the front of the cartridge (the middle image applying here). And you're right it will be very small adjustments. In my situation I'm able to adjust my removable headshell within the small tolerance at the actual contact point on the Technics tonearm and it changes the numbers considerably.

    [​IMG]

    The VTA test I was never able to figure out. I think I tried but, like you, never really heard what it said I should hear. I've since always done VTA by sight and by ear (I do it on the fly for each record, which might seem crazy, but after doing it this way for a while I don't think I can go back).

    There will be some inter-effects between anti-skate, azimuth, and fine balance, but given the dramatic dB swings you'll see in the azimuth/crosstalk numbers (eg. you can have 32 and 25 in the two channels, then a miniscule adjustment will get you to 26 and 29, then another the other way and you'll have 28 and 28) I think setting anti-stake and fine balance before azimuth best allows you to get azimuth right such that you don't have to touch it again.

    If I fiddle with those other settings after the fact, it never seems to affect the azimuth numbers enough to warrant re-adjusting it. The delta caused by anti-stake seems to be in the tenths of a dB, whereas I can't physically adjust azimuth to that specificity anyway; ie. a fraction of a millimeter the wrong way on azimuth will cause more like a 3dB swing. At least that's what I see on my table and arm, with my cart.

    So my preferred order with my Technics is:

    1. anti-stake
    2. fine balance
    3. azimuth
     
    captouch likes this.
  6. captouch

    captouch Forum Resident Thread Starter

    Location:
    Bay Area, CA
    Thanks, makes sense.

    Which adjustment do you mean when you say “fine balance”?
     
  7. YEX 750-1

    YEX 750-1 Long-winded Brother

    Location:
    Los Angeles, CA
    Basically just balancing the two channels of the cartridge. There is a “FineBal” setting in the Puffin test menu, to account for cartridge (or Puffin ADC) L/R imbalance in 0.1 dB steps. You can test and set it with a mono test signal or, I would think, a true mono cut record. The main difference between this and the regular menu Balance setting, aside from granularity, is that FineBal applies before the mono switch.

    However you might be using the Puffin as just a test device, and most analog phono preamps obviously won’t have this granular adjustment at the input so - while you can still test for it - you can also ignore it.
     
    captouch likes this.
  8. captouch

    captouch Forum Resident Thread Starter

    Location:
    Bay Area, CA
    Great, thanks again. I am actually just using the Puffin in my tape loop for click/pop suppression where needed and for setup.

    I was able to get both of my channels to 27.x dB on the azimuth setting. It didn’t change my anti-skate setting.

    Though I did find if I decreased my VTF by 0.15g, it affected the azimuth balance. I didn’t need to decrease the VTF, I was more curious, so I set it back to the old value where azimuth was balanced.

    Appreciate your guidance on this!
     
    YEX 750-1 likes this.

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