i am one of those "freaks" that you describe...
i have a number of arms and tables. the biggest challenge to fit a cartridge is my breuer 8C. it is said to like low mass cartridges, as does the black widow. well, the best fit for my breuer has been a heavier wood body benz micro H20 and the best fit for my black widow is the denon 103. i also have a moerch up4, yellow dot tube, which sounds spectacular with the benz H20. now that arm tube and cartridge do match for mass loading. i am also happy with the sound of my davinci grandezza using a benz ebony, even though the arm likes a cartridge 10gms heavier.
so don't get too messed up with mass loading/matching. it's a trial and error thing. some arms and some cartridges are more sensitive than others.
btw, that outboard arm pod that you mentioned is well worth the effort. i designed and built one. the sound improvement in detail and bass reproduction is amazing. check out pics in my gallery here.
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).
"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.
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.
+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.
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).
Thanks, Don. Some day I would really like to see how you designed that post. Perhaps if you are taking it apart for some reason or if you have a schematic(?)- although if you intended to patent/sell it, I'd understand ;-). No pressure. I just happen to reside in Aldershot, we're probably less than 10 miles away. Drop me a note on firstname.lastname@example.org if you get the urge.
And thanks to all for your answers. I will be trying the Herbie's dampers when I get the 103r and report back...
Update guys. I put the Akito 2b up for sale and it was gone in a couple of days. Hardly gave me time to order up the Jelco 750db, which I have since received and installed in the system, using both the GAS and a new 103r. Well, holy crap, synergy or what? It was like the linn arm was just not ideal for the table and cart choices (although it didnt sound 'bad' per se) and the Jelco was designed to be on it (maybe some truth there the sumiko mmt is a jelco). Form here in when I read someone talking at symetry and matching I'll be less of a sceptic.
Mickeyf,for some interesting reading check what Romy has to say on the subject of arm mass and compliance.
While I always thought he was a little of his rocker with some of the claims he has made over the years,thru my own experiences I find quite a bit of truth in his statements on this subject.
I am currently using an Aluminum bodied 103R on a 12" Jelco(26g) mated to an old Lenco idler and find this combo very musical.
PS. Romy is definetly not a fan of the 103 variants,but this is where I couldn't disagree more.
Glad things worked out so well, Mickey. May I trouble you with a side-issue question? There has been a good deal of debate about the tonearm geometry of the Jelco 750 arm (mostly on other forums). May I ask if you mounted the Jelco in the same hole you used for the Akito? If so, were you able to align the cartridge correctly without any problems?
The nature of the Jelco debate is that, although its effective length is specified as 229mm (identical to the Akito), some claim that it is actually longer, necessitating a different mounting position. Any light you can shed would be appreciated. Thanks!
Hot rod. I'll try to chew through that while I'm coasting in Key Largo next week. I've read his stuff before, he's a little verbose to say the least but definitely interesting.
Hey Bob. It is currently situate in a board that had overlapping holes for the linn and a prior RB300. I took a dremel tool to it, working in from the RB300 hole. (Ha ha it's starting to look like an SME hole). I think I am still a little further away than the current thinking. I have the cart right out to the end of the arm and on the lofgren protractor, I come up about 2mm short at the second grid. Apparently that's not huge, the sound is glorious.
I suppose I could do more playing around with the dremel and pull it in a few more mm's but the fact the sweep is on track most of the way in, suggests the hole is either too forward or too back as well. I want to order a new pre-cut board from SOTA but I am going to write and ask them how many mm's they will be drilling from the spindle upfront.
this board also had an air arm on it at one time, it's officially swiss cheese.
Thanks for the info, Mickey.
Bob, I was advised on another forum the spindle to pivot maybe should be 215-216mm whereas Jelco specifies 214mm. I'll get around to writing SOTA about it and see what they say and let you know.....
I think you and I read the same forums, Mickey!
Perhaps Bob. I got my information mainly from 'Blake' who posts frequently on Jelco and 103 related threads out and about. I note you are selling an MMT which should be pretty much identical to the Jelco although from the specs it looks like yours is a 10 inch? What table were you using that on?
I have not had a chance to write Sota yet, I will probably do that next week.
Hi Mickey. Actually, I have a couple of MMTs. I'm selling one and keeping the one I have mounted on my old but trusty Oracle Paris. Both arms are pretty much identical in condition, operation, etc., but I'd been looking for an auxiliary counterweight that came with the MMT originally. I had to buy a whole 'nother MMT to get one!
The MMT works and sounds great with my Soundsmith-retipped Shelter 501 II. The MMT effective length is 239mm, 10mm longer than the Jelco arm. I've been keeping an eye out for info on the Jelco because I thought it would be nice to have what is, more or less, a modern version of the MMT. I'd go ahead and buy a new Jelco, but of course, the mounting distance is different and I'm not too good at making mounting plates!
Do you ALWAYS have fluid in your MMT/750/370; or only when you would turn the cap up greater than minimum? I always interpreted 'We recommend using fluid damping only for cartridges with dynamic compliance <9' to mean you don't need fluid. Then I thought, maybe it means there should be fluid in the reservoir; but the adjustment should be minimum. My Shure V15 with brush is mounted at the moment. I added a few drops of fluid and raised the knob and it seem the sibilants are more pleasant and there's a bit more ring to cymbals.