Looking for a vintage (japanese) direct drive

Discussion in 'Audio Hardware' started by bever70, Jan 27, 2019.

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  1. patient_ot

    patient_ot Senior Member

    Location:
    USA
    @Vinyl Addict, I don't think I'm doing that. I'm going by the numbers in the manual for effective mass. For my QL-F4, the JVC manual lists it the same way. 14g for the tonearm and 7g for the headshell. That's 21g altogether, which they also list. With a 10g aftermarket headshell, the arm becomes heavier.

    With the Goldring 1042, a low side of medium compliance cart (10 @10hz), I used a test record to measure the resonant frequency and got a number between 9-10hz.

    I did try a high compliance cart on my JVC, an Ortofon F15E (25cu @10hz). The sound was horrible, with muddy bass, just like that type of compliance mismatch usually sounds.
     
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  2. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    @patient_ot - 99.99% of EM numbers are calculated with the stock headshell included. Typically you don't add that back in. The EM for the A7 is 14g search around. No way its 23.5g that is ridiculously high for that platform!!!!

    If you've been adding your cart weight to your EM numbers, you may want to dig and reassess... chances are you're compliance matching is skewed!
     
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  3. patient_ot

    patient_ot Senior Member

    Location:
    USA
    @bever70, while we are on this subject I would recommend getting a good test record if you don't have one. By that I mean something that's pressed well and will produce accurate results. I use the CBS STR100 which you can still find in NM condition for reasonable prices. Some of these newer test records are off-center and warped, making them useless. The STR100 is still used in many test situations today and is very highly regarded. I think I paid less than $10 for mine.
     
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  4. bever70

    bever70 Let No-one Live Rent Free in Your Head! Thread Starter

    Location:
    Belgium
    I hear you ;)! But I am not going the shipping-route, so I accept that choices will be more limited. As it is, I broadened my search to 3 neighbouring countries as well (that's why the Yamaha is a 5 hour round trip) but this is not the USA and choices are more limited....so I could wait and wait for the ultimate or I could strike when something comes along that I really like. Getting one of these doesn't prevent me from getting a better one later on when something eventually comes along and selling this one on. As it is I really like these 2 models ... The guy selling the JVC has a host of other dd's he's selling so maybe he has a few surprises up his sleeve :D.
     
    Last edited: Feb 1, 2019
  5. patient_ot

    patient_ot Senior Member

    Location:
    USA
    Again, I measured the resonant frequency with a test record and audio analyzer software.

    The manual says the headshell alone is 12.5g. You might think that includes the cartridge but you can weigh the headshell alone to verify it. When I weighed my JVC headshell, the number was for the headshell alone, no cart.

    For a total arm mass of 14g, that would mean that the arm tube by itself has an effective mass of 1.5g. Not likely.
     
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  6. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    OK, EM is calculated with stock headshell included. But not with cartridge included. We both agree there.

    But the cartridge weight does NOT get added to EM to give a new value. Not how it works. Cart weight is included in Compliance / Resonance calculation as a variable, just like the hardware is, but it is not a direct adder to EM.

    Adding weight to the headshell is not a linear equation to recalculating EM, it only boosts it by a fraction of that.

    If you are buying carts with the assumption that the A7 is a 24g EM platform, you will have TONS of trouble finding one! :)
     
  7. patient_ot

    patient_ot Senior Member

    Location:
    USA
    So I am looking at the owners manual and service manual for the QL-A7 and it would appear these two manuals contradict each other. In the service manual it says the headshell is 12.5g while the owners manual says 10g. The owner's manual also mentions a cart with 25 cu compliance, which is a higher compliance cartridge. Very odd. What I would do in this situation is take measurements using a test record to match your cartridge to the tonearm. It is possible that despite the tonearm weight, it is damped very well so it can accommodate higher compliance cartridges. A test record will tell you the truth here.
     
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  8. patient_ot

    patient_ot Senior Member

    Location:
    USA
    I was never including cartridge weight.

    Even with the 24g EM, you can still find carts that will work. Just not high compliance stuff. There are medium compliance carts still in production that would work fine. Goldring, Sumiko, LP Gear, and Ortofon have some on offer. Denon, but only old school models. Then there are vintage carts you can get new styli for.
     
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  9. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    To approach this another way -- let's say you have a TT that has an EM calculation of 14g EM, and that was calculated using a stock headshell of 10g. (again, EM numbers are calculated with the stock headshell included --- that's a given 99% of the time).

    Now, lets say you want to put a heavier headshell on there, say a 13g one. That does NOT mean the new EM is 17g (14g original + the additional 3g for the HS). EM and adding weight to the ends (counter weight or headshell) is not a linear relationship. In fact I use a 1/3rd to a 1/2 as a ballpark estimate of weight getting added back into EM ---- along the same lines as how most use the ballpark 1.5x to turn 100Hz dynamci compliance spec to 10hz for the resonance calculation.

    Again, if you are judging finding carts with the assumption of something like the A7 being a 24g EM platform, just saying you may want to take another look at the math / theory behind EM.

    Peace out bro.... :)
     
  10. patient_ot

    patient_ot Senior Member

    Location:
    USA
    I can agree that is all guesswork, which is why a test record is the best way to confirm compliance match. Calculations do not include tonearm damping. They just get us in a rough ballpark where there may be some wiggle room. Test record all day unless you have a crazy test rig like George Merrill.
     
  11. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    Bever70 - the topic patient and I are (patiently) discussing might seem like voodoo, but Google Effective Mass and Compliance / Cartridge matching --- it's a good topic to know.

    Now, these days many TT's are in the medium - high effective mass range, plus most cartridges made are in the same range, so without even thinking about it you'll probably be OK.

    It comes more into play when you are thinking of adding low compliance cartridges (like the DL-103, DL-102) or very high compliance cartridges to your system. Most of the mainstream Audio Technica, Nagaoka, Ortofon, etc all fall into the the medium to medium high category, and are fine matches with 80% of the TT"s.

    But it is still good to know the theory and calcs if you are into that sort of thing.
     
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  12. bever70

    bever70 Let No-one Live Rent Free in Your Head! Thread Starter

    Location:
    Belgium
    EM of the Yamaha is 15gr, stock headshell is 9gr according to the manual. Advised cart weight between 3-12gr. No mention of compliance ...
     
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  13. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    Yup. On vinyl engine (or in your spreadsheet :), use 15gr, and add in 1 gram for the HW.

    I created a really cool spreadsheet that has the simple calc in there, but also allows one to play with different headshells to see resultant Compliance / Resonance frequency. Vinyl engine has the table or the manual calculator --- I used to use the calculator instead of the table before I created my Spreadsheet.
     
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  14. patient_ot

    patient_ot Senior Member

    Location:
    USA
    @bever70

    Here are some links you can check out:

    Resonance frequency

    TONEARM/CARTRIDGE COMPATABILITY | Galen Carol Audio | Galen Carol Audio

    Cartridge Resonance Evaluator - Vinyl Engine

    Resonance Frequency


    Just remember that for any calculator, 1) it doesn't factor the damping of the tonearm and 2) Japanese cart makers sometimes list compliance at 100hz rather than 10hz, these numbers have to be converted using rough estimate math (many people multiply by 1.7 or so). Not an exact science

    Again, a test record is good to have here.
     
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  15. bever70

    bever70 Let No-one Live Rent Free in Your Head! Thread Starter

    Location:
    Belgium
    I know the basic stuff about this (my dealer is a good teacher ;-) ). I went through most of this when we were deciding on a fitting cart for my TP16 arm on the Thorens.That's also when I found out that Nagaoka measures things differently.
    I just don't really know which cart(s) are in what category (low, medium, high compliance) without looking it up. Knowledge might come with time ;-).
     
    Last edited: Feb 1, 2019
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  16. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    @bever70 - remember one of the tools I said was a great resource to see how TT's rank / stack up by sales price? Take a look at historical sales, filtered by "Yamaha YP-D" ---- you'll see your DP-71 there too. It's a fine TT.... just providing as a resource. https://www.hifido.co.jp/sold/?M=&LNG=E&G=1&KW=yamaha+yp-d

    80% of the time HiFiDo historical sales price helps you sort out relative worth / value of a particular item on the resale market. Ebay or other resources CAN be good when using Sold Listings, but Ebay is definitely not good for determining with items still for sale, prices are all over the map. BUT, there are not a lot of great value determining resources for Japanese DD's --- HiFiDo is one of the best. There are many popular DD TT's that sell here in the US and fetch a lot more than they would if sold in Japan (it's the popularity aspect and what we have stateside). Some of the Denon DD's and the SL-1200 are great examples of this.

    Anyway, just giving you tools.
     
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  17. Davey

    Davey NP: Hania Rani/Dobrawa Czocher ~ Inner Symphonies

    Location:
    SF Bay Area, USA
    Well, the cartridge weight with hardware is just added to the effective mass to do the calculation, it is a linear relationship since I think the cartridge center of mass is just assumed to be over the stylus. The headshell is a little different since the center of mass is always gonna be behind the stylus, so often we use 80 to 90% as the effective mass increase for the headshell (ie, a 10 g headshell adds 8-9 g to effective mass).

    BTW, if you don't believe me, just go the the VE resonance calculator and enter 15 g for effective tonearm mass and then look at resonance with 5 g cartridge at 15 cu compliance (9 Hz), then lower effective mass to 10 g and check with a 10 g cartridge at 15 cu (9 Hz). Same 20 g effective mass in both cases and same 9Hz resonant frequency calculation at 15 cu compliance.
     
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  18. allied333

    allied333 Audiophile

    Location:
    nowhere
    Both the Yamaha & JVC are very good TTs. I would 'slightly lean' towards the Yamaha myself. The Yamaha sells for about twice as much as the JVC.
     
  19. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    Great resource / info.:righton:

    As mentioned here, and to build on what Patient provided --- when you look at cartridge specs from 90% of the manufacturers, and doing compliance calcs ---

    • First, you are looking for the DYNAMIC compliance number NOT the static compliance number (which is typically much higher)
    • Sometimes it's hard to find dynamic compliance of a cart --- some manufacturers are good about providing (like AT) others are not, just like it can be hard to find EM for some TT's. SOmetimes it takes a little digging.
    • The rule of thumb Patient touched on above --- it is a "sliding scale" --- for cartridges that have a 100hz dynamic compliance in the 5-8 cu range (low compliance carts like the DL-103), I use 1.5x as the multiplier. For 9-15 cu I use 1.75, and for higher I use 2. MOST use 175 like Patient said as an average. But it is a sliding scale as the relationship is not a linear one.

    You may already know all this.
     
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  20. bever70

    bever70 Let No-one Live Rent Free in Your Head! Thread Starter

    Location:
    Belgium
    Thanks, they are pretty much in the same ballpark as the jvc ql-a7, allthough they are sold in lesser numbers then the jvc. I used ebay sold items as well for different models . Conclusion is that prices over here in Europe are a lot steeper than in the US.
     
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  21. Davey

    Davey NP: Hania Rani/Dobrawa Czocher ~ Inner Symphonies

    Location:
    SF Bay Area, USA
    Yea, it kind of depends on how you are used to playing records, the lack of manual operation for cueing with the Yamaha could get in the way, always having to turn it off and on and move the tonearm to the rest to do anything, I wouldn't like that, but if it was your only table, you'd probably get used to it after awhile. May be easier to use than I think, afterall, these were made for the average consumer in the 70s.
     
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  22. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    It sees you've reinforced what I said but couched the reply with not agreeing??? I think it is to what degree we may differ, but our point is the same. You say 80%, I say it's less more like half to two thirds.

    So again we are actually on the same wavelength if I read your reply correctly.

    BUT if your bottom line point is that adding weight to a headshell is a linear adder to overall EM, then we have two different interpretations, and don't agree.
     
  23. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    YES DEFINITELY!!! :)

    The intent of the Hifido is to give a RELATIVE value against other Japanese DD TT"s from the source - or where they are made, and by those who sell them regularly!!!

    Yes agreed, US, Europe, other locations --- resale price becomes relative to local popularity and other factors (taxes, availability) --- but again sometimes those prices don't reflect well to one TT against another in the local market.
     
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  24. TheVinylAddict

    TheVinylAddict Look what I found

    Location:
    AZ
    Actually, its the reverse on the Japanese market. Where did you get that assessment? That is counter to what I've found.

    Actually the A7 sells for a little more than the D71.

    https://www.hifido.co.jp/sold/?M=&LNG=E&G=0301&KW=+ql-a7

    versus

    Results for YP-D71HiFi-Do McIntosh/JBL/audio-technica/Jeff Rowland/Accuphase

    If you question the numbers above, I will say in advance there is not better resource online to calculate relative value of Japanese DD vintage TT;'s
     
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  25. bever70

    bever70 Let No-one Live Rent Free in Your Head! Thread Starter

    Location:
    Belgium
    Correct, the a7 has a slightly higher value than the dp71.

    Results for Victor ql-a7HiFi-Do McIntosh/JBL/audio-technica/Jeff Rowland/Accuphase
     
    Last edited: Feb 1, 2019
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