Any ADC experts out there?

Discussion in 'Turntables' started by bigaltx24, Dec 18, 2017.

  1. wualta

    wualta < Spike Milligan, 1961

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    Location:
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    Measure it to be sure, but that's almost certainly the low-inductance (260mH) Integra, usually showing up with a CF-100 stylus, which won't be easy to find. Though it's basically an Integra QLM 36 Mk II (also hard to find), any Integra stylus will do the job. The 114-DET would be my top pick. If you don't want to throw that much money at it, there are K-series styli that will work, and a few good aftermarket versions.

    This particular Integra variant can be spotted by the extra-thick thumbscrews on either side.
    2a.jpg
     
    Last edited: Jun 19, 2018
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  2. Evonimos

    Evonimos Member

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    85
    Excuse me for bringing this thread up, but I just got my hands on an ADC QLM30 mkIII cartridge (nos).
    I tried it on my Technics SL1200mkII and it sounds very good!
    Soundstage is huge and the sound is detailed and crisp.
    I'm really surprised by the performance from this one.

    However, my cartridge came in a private market boxing, with neither any instructions, nor specifications.
    I did some looking around and it seems this wants to track at 3-5 grams. Correct me if I am wrong.

    What I was unable to verify, is the output from this cartridge.
    Just by listening to it, seems to be on the lower side of things.
    From experience I would guess it's around 3mV (@5cm/s)??
    The few specifications I 've found online, are all over the place.
    Anywhere from 1mV (@5cm/s?) to 7+mV.
    I am puzzled...

    Any help would be appreciated.
    Thanks.
     
  3. revox-b77

    revox-b77 AK Subscriber Subscriber

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    Here is what I have for the QLM 30:

    SPECIFICATIONS:
    • Output voltage: 7.6 mV per channel at 1 kHz.; 5 cm./sec. peak recorded velocity.

    • Channel balance: 2.0 dB at 1 kHz.

    • Channel separation: 20 dB at 1 kHz.

    • Frequency response: 20-18 kHz ± 2 dB.

    • Tracking ability: 80 µm at 315Hz at recommended tracking force.

    • Stylus type: Brushed Spherical.

    • Stylus tip radius: 0.7 mil.

    • Tracking force range: 3.0-5.0 g (30-50 mN).

    • Recommended tracking force: 3.0 g (30 mN).

    • Tracking angle: 20°.

    • Optimum load: 47, 000 ohms resistance in parallel with 275 to picofarads total capacitance.

    • Cartridge weight: 5.75 g.

    • Mounting: Standard 1/2" (12.7mm) Mounting Centers.

    • Replacement stylus: RSQ30.
     
  4. Evonimos

    Evonimos Member

    Messages:
    85
    Thanks for the reply!

    Strange thing is that on another forum, I came upon this:
    [​IMG]
    Here it states the QLM30mkIII(like mine), to have a much lower output (1.5mV)?
    And even more strangely, the QLM33mkIII, also a conical, is stated @ 5.8mV??

    Since there is no reference regarding the velocity at which they output is specified, it make things even more confusing.

    However, my QLM30mkIII, sound like more like a 3mV output than a 7.8mV one.
    Is it possible, that there is something wrong with the stylus, or the way it is inserted into the body, affecting its output??
    Thanks again!
     
  5. wualta

    wualta < Spike Milligan, 1961

    Messages:
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    Location:
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    That chart is a homemade one, not an ADC publication. Inevitably errors or ambiguous bits sneak in. In this case, the 1.5mV figure is meant to be per centimeter per second. Measured at a velocity of 5.0 cm/sec, that translates to a 7.5 mV output, close to the official 7.8 mV that shows up in all the official spec sheets I have.

    Having said that, it's possible to cock the stylus slightly on insertion and this will reduce the output. Slide it straight on to the body and you should be at spec. Through all this, I'm assuming you have a genuine ADC stylus, not a generic.
     
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  6. boreas

    boreas "If it sounds good, it IS good." E.K.E. Subscriber

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    It's also possible to push the cantilever partially out of the suspension bushing as you install the stylus. Double check the stylus. You should see a bit of exposed cantilever on the back side of the suspension block, about .5 to 1 millimeter protruding from the block.
     
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  7. Evonimos

    Evonimos Member

    Messages:
    85
    Thank you for the replies.

    I will post some pictures of what i have.
    I am pretty sure it is an original stylus though.

    I got the cart from Gary and it is my first experience with ADC so i know very little.

    If measure the coils with a multimeter, would it do any damage?
     
  8. Evonimos

    Evonimos Member

    Messages:
    85
    I took some pictures and Ohm measurements on the coils with a digital multimeter.

    Left coil: 360 Ohms
    Right coil: 355 Ohms

    I suspect these figures to be a bit off from the expected Ohms..(?)
    Someone said that the bodies like mine, with the plastic protruding dots on the backside of the bodies, were measuring differently.
    I do not remember where I have read that...

    Are there any QLM bodies that are close to my measurements??

    Also, how do the pictures look to you?

    Any help would be appreciated.

    Here are the pictures:
    20180914_215251.jpg
    20180914_220227.jpg
    20180914_215743.jpg
    20180914_220005.jpg
     
    Last edited: Sep 14, 2018 at 3:27 PM
  9. wualta

    wualta < Spike Milligan, 1961

    Messages:
    7,384
    Location:
    West Michigan USA
    The ohms readings are consistent with the QLM 30 Mk III. QLM bodies measure lower in resistance than their XLM/VLM/ZLM brethren.
    The dots comment was expressly speculation.
    The stylus is genuine and it appears to be inserted properly.
    Am I correct in understanding that your complaint has to do strictly with the cartridge's output voltage?
     
  10. paul300b

    paul300b New Member

    Messages:
    46
    Looks like the magnet is missing from the front of the stylus....
     
  11. wualta

    wualta < Spike Milligan, 1961

    Messages:
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    Location:
    West Michigan USA
    No, the QLM 30 has a flat magnet.
     

     

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  12. Evonimos

    Evonimos Member

    Messages:
    85
    Not a complaint per se.
    I am just worried whether the cartridge body is the the right match for the RQ30 stylus.
    I was expecting a higher resistance and a louder signal output, according to the specified figures.

    So, I understand that around 360 Ohms are correct for this body(?).

    That would great because this QLM30 mkIII cartridge sounds rather excellent.
    I'm positively surprised by its detailed sound and very wide soundstage.

    Can i use the RQ33 stylus on this body?
    Are they compatible?
     
  13. wualta

    wualta < Spike Milligan, 1961

    Messages:
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    Location:
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    Yes, your 30 was properly used in a body with around 270mH and roughly 350 ohms. Glad you're liking the sound of the 30. It's long been my contention that Pritchard's basic cartridge design scaled up and down equally well, and the 30 Mk III and 32 Mk III were ADC's bottom of the line and, alone among the ADC's Mk III models, used the same body.

    I wish I could answer your question about the RQ33, which looks like an upgraded version of the 30. It's just that the specs we have for the 33 don't tell us whether its body was the same as the 30's or not, and few owners have stepped forward with measurements. However, there's another good conical stylus that works properly in the 30 body: the K8. Right now it's available on eBay for $13 shipped. Search for the phrase "Original ADC K8 Phono Stylus". It's genuine ADC, tracks well at 2.0 g, sounds very good, and the price can't be beat.
     
    Last edited: Sep 15, 2018 at 11:02 AM
  14. Evonimos

    Evonimos Member

    Messages:
    85
    Thanks Wualta!
    Went straight for that ADC stylus you recommended.
    Problem is the guy does not ship overseas..

    So, from a little research on this, it seems that my body is the same as the Integra CF100??
    The resistance I measured was 360 Ohms on mine (ADC QLK mkIII).
    Wualta, what are your thoughts on that?
    Would it be possible to fit the needles from that on mine?

    [​IMG]

    I also found these specs:
    [​IMG]

    Are these for a different family than mine?
    Replacement styli names are different?
    Forgive my confusion, but it's all new to me.
     
    Last edited: Sep 15, 2018 at 7:54 AM
  15. wualta

    wualta < Spike Milligan, 1961

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    Location:
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    Yes, the CF-100 stylus, if you can find one (they're not common in the US), will work properly in your 30 body.
    The Japanese ADC leaflet shows the correct replacement stylus names, so I don't understand your statement/question.
    Here's the US spec sheet for the QLM Mk IIIs:
    ADC QLM 34, 33, 32, 30 Mk III.jpg
     
  16. Evonimos

    Evonimos Member

    Messages:
    85
    Sorry.
    I'm mixed up. I thought that the correct nomenclature is RQ##, without the S.
    There is a lot of stuff in my head right now..

    Wualta, between the RK5E and the RSQ34, which one would you reccommend?
     

     

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  17. wualta

    wualta < Spike Milligan, 1961

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    Location:
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    Confusion with any of these old cartridges and styli is very understandable.

    RQ was for the Q (not QLM) series that came before the QLMs (Q30, Q32, etc; also Q301, Q321, etc).
    RQLM for was for the QLM Mk II series.
    RSQ was for the QLM Mk III series.

    The RK5E (also known as the RK50E made for the Tandy/Radio Shack chain of stores) will fit and work properly in your 30 body.
    The RSQ34 stylus is meant for a body that looks the same as the 30's but differs electrically. It will fit your 30, but the high treble will increase, which most people find unpleasant.
     
  18. Evonimos

    Evonimos Member

    Messages:
    85
    Indeed..
    By the way, thank you for all the information Wualta!
    Very much appreciated.

    I will probably try the RK5E, which seems to have 0.3x0.7mil tip.
    It is a tip that I am familiar with.
    I 'm curious to listen to the possible differences it'll have with my current 0.7mil tip.

    As you can tell, I am quite impressed by the performance of that lowly QLM30mkIII cartridge.
    Very nice sound!
    If that bottom of the barrel model sounds so good, I wonder how might other perform.
     
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  19. bigaltx24

    bigaltx24 Super Member

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    I installed an EVG 4108-DET on XLM? body. It took a little time to break in, but now it's one of my favorite cartridges.
     
  20. wualta

    wualta < Spike Milligan, 1961

    Messages:
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    Location:
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    The 4108-DET sold by thevoiceofmusic.com is a solid performer for little money, but it's suited to the higher-inductance bodies, ie, the Integras and the Mk III XLMs, VLM, ZLM and QLM 34 & 36.
     

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