Technics headshell weight/ Audio Technica 440mla c



I've researched the above and found inconsistent results: Can anyone tell me the actual weight of a Technics headshell??? Needle Doctor says 5.67 gms. and others say the headshell weighs 7.5 Gms! [Sl 1200/1300} as original equipment. While you're at it, what is the consensus as to the compliance of an AT 440mla; I've read 10 and as much as 18.
boofer

Showing 3 responses by fleib

Hi, The headshell weighs about 7.5g with wires and I would guess from what you say, 5.67g without.

AT 440 compliance is 10 @ 100Hz = 18 @ 10Hz.
Calculations for resonant frequency use 10Hz figures.

Lots of people use 440s on the 1200. It should be a good match. I'd recommend supplied aluminum screws. I also replaced the headshell wires with silk wrapped ones and seemed to get nicer sound, although on a different arm.
Regards,
Hi Boofer, Effect mass without headshell might be a meaningless concept, depending on what you're trying to calculate. I guess you could look at it that way as long as you're using standard SME style headshells, but your results for E mass will be an approximation. Weight distribution might be different. Weight behind the cartridge should contribute less to E mass than weight at, or in front of the cart. BTW, calculations for resonant frequency are also an approximation. For an exact resonant frequency, get a test record.

I'm not positive if that weight distribution aspect is still valid. On Karma a physicist called Luckydog recently said, due to a quirk in the math for common arm lengths E mass is not increased solely due to length. I haven't quite digested all the implications. E mass is the same as MOI and distance from the center of rotation is a factor.

The 1200, like a Rega has a med/light arm suitable for a wide range of carts. Maybe people were thinking of the SME series III which has E mass of something like 5g? At any rate I suspect you're overthinking this aspect. While a "perfect" resonance of 10Hz is one octave above 5Hz warp frequency and one octave below the audible band, there might be other synergistic factors that are of greater importance. Where you get into real trouble is with a low compliance cart on a low mass arm. If the resonance approaches the audible band you're likely to get intermodulation distortion from that resonance.

The consequences of a low resonance frequency are tracking warps and susceptibility to mechanical and acoustic feedback. If that's not a problem then SQ is the other consideration. Often a med/high cu cart can sound sluggish dragging a high mass arm around, but it's hard to generalize. In such a situation arm quality, rigidity, bearing friction, etc. might be of greater importance.

If you're interested in a more detailed discussion you're welcome to join in here:
http://www.audiocircle.com/index.php?topic=88878.620
Bottom of page 32.
Regards,

Boofer, Weight and eff mass are not the same thing. If you google eff mass you'll see that computations are complex.
3.5g arm tube weight seems light for the Ortofon 110, but I really don't know. I would think the headshell connector and collet would weigh a couple of grams?

VE publishes mfg specs and eff mass would include stock headshell. There might be some mistakes there, just as there are in the cart database. Once again, if you get a test record you can see resonance without having to get a scope. If you use carts of known compliance and know fastener weight, you can use the calculators to solve for eff mass. Your AT carts 440 (18cu) and Virtuoso (15cu) and Ortofon should average out to a good estimate. Some other hand made carts might vary more from mfg specs.

I looked up the 1300. The description of the motor reads similarly to that of the VPI Classic Direct. The revolutionary design uses the platter as the rotor and the base as the stator. It also has a brushless motor. Earlier designs had the platter sitting on the rotor. VPI has the platter as rotor and a circuit board stator and such niceties as a 20lb platter, massive base and expensive motor and 3D arm. So it's essentially the same, give or take about $29,900?

Joking aside, you don't need a million dollar record player to enjoy a record. If you haven't already added weight inside the 1300, that should go a long way toward solidifying the sound. Non-hardening modeling clay is easy to work and lead is great for slowing vibrations. Just leave room for the motor to breathe.

The Cadenza line gives an interesting view of voicing a cart. Yours has a fine line on an al cantilever. Blue has FG 70/ruby, bronze has tapered al/Replicant and Black is boron/shibata. When yours wears, you could send it to Soundsmith for a level 3 and it should be similar to a Blue. It's interesting that Bronze goes back to al with the Replicant tip. It looks like the generators are the same.

If you're comparing the tables with different carts, it might be apples to oranges, although sometimes you can tell. Enjoy.
Regards,