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tonearm/cartridge matching, mass/damping/tweaking

I'm reading more and more, here and mostly elsewhere about matching cartrdge compliance to tonearm mass. Of course, the wonderful but also dreaded Denon 103/103r s are front in centre in most debates.
I recently swapped out my denon 103 for my nos GAS Sleeping Beauty and perceived a better overall sound although it just may be a better overall cart too, who knows?
I am running a Linn Akito 2b arm which is said to be a little low on the mass side for the Denon 103 at I think 11 grams. i have seen some raging debates with guys saying their black widow (really low mass) arm matches just great with a 103, and a mass proponent saying that you need at least 25 gram mass arm for the 103R (although his 'perfectly matched' jelco 750d is ironically an 18g mass arm....). being a sucker for punishment I have on order both a 301mkii and a 103r (my audiophile nervosa has ingrained me with the fear that 'they' may stop making cartridges - after all, I have read that the venerable technicss DD tables have been discontinued). Now, I could simply likely sell my Akito 2B and buy a Jelco 750db and be done with it. resurrect my light headshell for use with the 301 and start having swapping fun. WTF, I could prolly also build up an outboard tonearm stand and run a 12" jelco outside my SOTA opposite the akito2b and turn into a real freak (sorry to all you freaks out there, you know what you are ;-)).
I have read some possible arm tuning damping ideas too that dont smell of overdoing it. One being laying a couple of pieces of tonearm litz between the cart and the headshell when mounting to decouple slightly. Another is the adddition of herbie's hal-o jr's to the arm wand which is cheap maybe effective and readily reversible (unlike wrapping the wand).
i gotta wonder just how accurate some of these mass and compliance calcs are too. ironically, i had to use a supplied sheet of what appears to be lead with my GAS to give it sufficient weight to use with this arm and it is only a few grams less than the denon....
Any thoughts, ideas, current thinking on the mass vs compliance issues?
mickeyf
mickeyf OP
153 posts
 
Hey Don, shock and awe come to mind, and thank you for your thoughts on this.
The arm pod is inspiring (the pics on your CAM gallery give a better perspective). I'm guessing the three feet are adjustable for levelling and come to points/spikes? Also, it appears the set screw in the upper pod is for the purpose of rotation only, and the height/vta is adjusted with the knurled tower? Being neither a machinist or an engineer, I think that aspect of it may be a little out of my league- I'm having a bit of a hard time visualizing how the height adjustment functions, but I imagine it works 'on the fly'. All goofing aside, I would like to try doing something like that at some point....
Coincidentally, one of the 'debates' I'm referring to happened on CAM recently and was what got me thinking more about matching. Generally, one of the things I'm wondering about too is how 'effective mass' is really determined. Some suggest adding weight to the headshell is increasing mass. If that is true, does adding 2 Herbie's dampers @ 5.65 grams each increase effective mass of the arm by 11.3 grams? Anybody tried this for that specific purpose and will it alleviate the vibrations travelling back on the arm from the 103, or might it muddy the sound? (I am going to try it, just wondering what result others might have had).
lewm
6,770 posts
 
"does adding 2 Herbie's dampers @ 5.65 grams each increase effective mass of the arm by 11.3 grams?"

I think the answer is yes, since the added mass will be situated essentially right above the stylus tip. If the added mass is displaced to the rear, toward the pivot, then the increase in "effective mass" will be related to the square of the distance between the stylus and the added mass. Formulae are somewhere on the internet. Try Vinyl Engine.
viridian's avatar
viridian
4,184 posts
 
I think that there are at least two issues at play here. First is simply the primary arm/cartridge resonance issue, which is fairly easy to calculate.

The secondary issue is how the arm deals with the added energy that excites it from a low compliance cartridge. The suspension of a high compliance cartridge absorbs much of the resonant activity of the cantilever/record interface. This is less true with a low compliance cartidge. I think that the results are pretty unpredictable and that leads to the art part of the tonearm/cartridge match.

My experience, owning both a Denon 103D and a 103 is that very heavy - 25 gram + effective mass arms with tight, captured bearings work the best. YMMV. The Black Widow may actually be a special case as the carbon fiber arm tube is very well damped with a different resonant signature than aluminum.

Unfortunately, since both effects are always at play, it is hard to seperate the two.
dougdeacon
3,338 posts
 
+1 for Viridian's post.

The formula everybody frets about only addresses his first point, which is fairly trivially easy to get right. The hard part is his second point.
corby
80 posts
 
mickey
to answer your question on the arm pod:
the three feet do come to points for adjusting azimuth. the knurled knob on the side locks in the post that raises and lowers for adjusting stylus rake angle via the micrometer on the top of the post (can be done on the fly).
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