Denon DL-S1 on a Jelco 750

[worrasf]

Just wondering if the collective knowledge on AoS has "solved" the vexed issue of the true effective mass of the Jelco 750?
Most of us are aware that the stated EM seems to be illogical and variable (https://www.vinylengine.com/turntabl...p?f=18&t=60600)
I have just acquired a low hours DL-S1 at a very good price and will be using it in my Jelco 750 (currently using a Goldbug Mr Brier & Northwest Analogue special DL-103).
The question of correct effective mass is related to choice of headshell for the DL-S1 as I currently have a very nice Orsonic AV101s (16g) doing nothing. If the Jelco EM is indeed 13.48 (with standard headshell of 12g) then using the Orsonic will take this up to 17.48. The DL-S1 is 8g with a compliance of 14 x 10-6 cm/Dyne and should be a very good match resonance-wise. However, if the true EM is up around 20g as many suggest the Orsonic will be a bit heavy and would be at the limit of acceptable resonance so I'd need to get a lighter headshell.
It's no big deal but worth asking the question as I guess someone may have direct experience.
Steve


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[Ammonite Audio]

Suck it and see - it will almost certainly be fine. In my experience you are far more likely to run into problems when using a MC cartridge in a tonearm which has too little mass, rather than one with bit more mass than the theoretical optimum.

[blake]

EM is probably around 19-20 with stock headshell. I, as well as others, have an email from Jelco stating an effective mass of 20, although others have received different information obviously.

I've always run the arm with damping, which is designed to make the arm more flexible with cartridges with varying degrees of compliance. Over the years (about 8 now), I've run the arm with a number of different cartridges, mainly Denon 103R's in various bodies ranging from stock to Ebony to aluminum, and more recently with a couple of rebuilt Ortofon MC 20 Supers.

The MC 20 Super has a compliance of 15 vs. the S1's 14 and sounds superb in my set up (with a Yamamoto carbon fiber headshell that might weigh about a gram less than the stock headshell). So my gut feeling is that anything heavier than the stock headshell is unnecessary, although my MC 20 Supers are 9 grams vs the S1's 7 grams. Not that a heavier headshell will not sound better if it is indeed superior to the stock; you'll just have to experiment to see.

That's the long answer.

Short answer is that I'm sure it will work fine. The more pressing issue will probably be dealing with cartridge/phono stage matchup with the S1's low output and higher internal impedance to really get the best out of it.

[Barry]

Denon quote the compliance at 100Hz, so at ~10Hz it will be 1.5 - 2.0x higher. Thus given a total mass of 25.48g, the calculated low frequency resonance will lay between 5.9 - 6.9Hz. Raising the EM to 28g, these figures become 5.6 - 6.5Hz.

Both sets of figures are ideally too low, but depending on the immunity of your TT to external vibration you may not experience any problems. As has been said: "suck it and see".

[worrasf]

Short answer is that I'm sure it will work fine. The more pressing issue will probably be dealing with cartridge/phono stage matchup with the S1's low output and higher internal impedance to really get the best out of it.

In the first instance I'll be using a Denon AU-320 SUT which will be an acceptable if not perfect combo until I can locate an AU-1000 at a reasonable price (beware of low flying pigs)

Phonostage wise I'm using a Croft 25RS which Glenn modified so as to increase the gain from standard as my DH-103 has an output of <.2mV so I should have no issues with the S1 in this regard,

If I do get another headshell it will be another Isokinetic SM Jelco which I'm currently using with my DH-103 and very happy with.





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[helma]

The Denon specified compliance of 14cu is most likely @ 100Hz, which makes obtaining the "real" compliance @10Hz a guessing game unless someone has actually measured it. Probably around 20cu or a bit over? For comparison Ortofon cartridges specified at 15cu or around routinely track at 2g and over. While tracking force doesn't necessarily have a direct connection with dynamic compliance, with the vast majority of cartridges it's a pretty reliable way to estimate ballpark compliance. Based on those tentative numbers the 16g Orsonic really seems like pushing it, however this is just pure speculation to pass the time while waiting for someone who actually has the experience to chime in

[blake]

The Denon specified compliance of 14cu is most likely @ 100Hz, which makes obtaining the "real" compliance @10Hz a guessing game unless someone has actually measured it. Probably around 20cu or a bit over? For comparison Ortofon cartridges specified at 15cu or around routinely track at 2g and over. While tracking force doesn't necessarily have a direct connection with dynamic compliance, with the vast majority of cartridges it's a pretty reliable way to estimate ballpark compliance. Based on those tentative numbers the 16g Orsonic really seems like pushing it, however this is just pure speculation to pass the time while waiting for someone who actually has the experience to chime in

Agreed. Bumping up to a 16 gram headshell from the stock 12 gram version would seem unnecessary as I stated above, if not detrimental. Sticking with headshells in the 9-12 gram range would seem like a better idea with the S1.

My Ortofon MC 20 Supers track at 1.8 grams (range from Ortofon 1.6 to 2 grams). With the fluid damping engaged the 750 is pretty versatile when it comes to cartridges.

[paul(555)]

I hadn't recognised the difference in Denon's compliance measurements, compared to the usual 10Hz, before reading this, so very useful information, thanks.
I've just rechecked the resonance point for my DL-S1 and Alphason HR100MCS, still just OK thankfully.

[worrasf]

Agreed. Bumping up to a 16 gram headshell from the stock 12 gram version would seem unnecessary as I stated above, if not detrimental. Sticking with headshells in the 9-12 gram range would seem like a better idea with the S1.

As stated in my OP it's purely because I do have a spare 16g headshell I asked the question- I don't have a stock one to hand so would have to buy one so not really a matter of "bumping it up"


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[blake]

As stated in my OP it's purely because I do have a spare 16g headshell I asked the question- I don't have a stock one to hand so would have to buy one so not really a matter of "bumping it up"


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Ok, did not realize that you did not have the stock on hand.

As you have both the Denon and Orsonic now, try them out, but definitely with fluid damping engaged.

If it doesn't work out, another lighter headshell would be in order; the Isokinetic SM would not make any more sense than the Orsonic under the circumstances obviously.