Abis SA-1 tonearm

[Johnny Vinyl]

I got the impression that Art Dudley in his recent review of the Oracle Delphi Mk VI Second Generation preferred this over the Oracle/SME combo. Rafe Arnott over at Part-Time Audiophile is working on a review of this same tonearm mounted on an Oracle Paris Mk VI. I'm looking forward to reading what he has to say. If favourable, it may be a good option for my own Paris Mk VI when I'm ready.



If anyone out there has any experience with this arm I'd love to hear from you!

JV

[Beaur]

I have the SA-1.2BCS model. The differences are silver wiring and the ability to negatively balance the arm. I haven't had it that long and I can only compare it to an SME 3009 V1 that was a little long in the tooth, on the table it's currently installed on.

The Abis so far is a damn good arm. It's easy to set up, has performed mechanically flawlessly and tracks beautifully. It's hard for me to get any kind of handle on it's ultimate performance as I have switched out a lot of equipment lately but so far I have no issues with it's audio performance either. It's a clear upgrade to the SME and I am enjoying playing music with it.

Beau

PS here's a link to the description of the arm and the "negative" balance. My arm came configured this way and I haven't changed it as it looks a bit difficult.

http://mockingbirddistribution.com/a...arms/sa1-2bcs/

[Garth]

Looks heavy how much mass does it have.

[Beaur]

Believe I remember the effective mass to be about 20g. It's definitely an arm for low compliance cartridges if you pay attention to such things. There is a fair amount of flexibility in some of the set up adjustments.

Looks heavy how much mass does it have.

[Rob]

it does look like a Dynavector 507...w/ an effective mass of 20g it pretty much eliminates it (for me) as a match for my favorite carts like the Lyra, Kanda's, Vdhs and ZYX carts.

What cart did Dudley use?

[Beaur]

What cart did Dudley use?

Looks like Art used a Denon 103 (what I have on for the moment), a Miyabi and a Miyajima Mono.

[Mockingbird]

I thought I could contribute to this, since I helped with the "mark 2" version of the arm. I helped to pick and model the geometry.

I've had a lot of interesting/strange discussions about the arm, having almost nothing to do with how it sounds. Herb and Art liked it enough to allow its inclusion in the latest Recommended Components issue, rated Class A! Excelsior!

Here are answers to FAQs (my snarky tone is nothing like the sound of the arm).

Looks: totally incidental that it looks like a Dynavector. The shape is dictated by the desire to use a detachable headshell, and to machine the arm from a block of billet material. You have to establish the offset angle, and cutting the arm at an angle, at the end, and attaching a holder for the collet, is the easiest to accomplish. There are other ways of doing it, but this one is easy to assemble and manufacture. BTW, the Dynavector can be said "to look like" ancient GE and Gray Research arms with articulating heads. The concept was very old when the Dynavector was developed. The idea came from the rotating heads for victrolas. It's the same! Look at how the arm swings across the record, and the "reproducer" swings up and down. Same as a Dynavector! See attached picture, then ask Nipper why he copied the Dynavector.

Mass: yes, when we stretched the arm, it got heavier. With the rotund 17 gram stock headshell, the effective mass is over 25. It's too heavy for many cartridges, but it sounds good and it's who they use for headshells. There are umpteen-hundred headshells available, new and used, to help match cartridge masses from high, to low, with compliance from "almost none" to medium-high. I am talking to Yamamoto Sound Craft about offering their headshells at reduced rates to Abis buyers (and maybe other parts to other people), with the goal of giving Abis buyers a high quality low-mass headshell for medium compliance cartridges. I have mounted high compliance Shures on 5 gram headshells, and it worked (see Mass+ below). So, with low mass headshells and low mass hardware, medium compliance cartridges work fine. The bearings are good, so there has never been a problem with woofer cone pumping. A high compliance cartridge will "wobble", then recover. With a low compliance cartridge, the cartridge is like "so what".

Mass+: You can change the effective mass of the arm by varying the positions of the two weights. The closer the two weights to the pivot point, the lower the effective mass. So, with a medium compliance cartridge, I move the front weight all the way back, and use the main counterweight. This gives you some adjustment over cartridge behavior, too. I spoke to George Merrill about removing the sliding weight and associated hardware, to test the effective mass again. You'd still be able to add mass (the hole at the front of the tonearm is there to add an additional 3 gram weight, though I've never seen anything that would need it).

Other materials: people have asked "when are you going to make the arm out of BLAHBLAH material?" It's simple, really. Just put down a deposit, and I'll research raw materials, setup time, shop time, finishing (paint? plating?), postage, assembly in Tokyo, postage back to the USA, profit, and the final cost. Not hard. The arm can be made of any material, though some materials are impractical. If someone wants one cut from gold, we'll find the market price for gold, find someone to cast an ingot of appropriate dimensions, and start from there. Magnesium? My friend cuts magnesium parts for aerospace clients. No problem. Titanium? It's easier to cut than stainless steel if you choose the proper inserts. Inconel? Hastelloy? Ice? Bronze? Brass? Copper? Butter? Wood? Diamond moon rock? Sintered tungsten carbide? Ceramics? It's easy to make anything with a budget. But, 99% of the people that ask "when are you going to make one of magnesium" are never going to buy an arm. They sit around on forums, like Monday morning quarterbacks, saying how they would make it. You want one made of Panzerholz or phenolic or human bone, then plated to form a Faraday cage? Anything can be made. The Butter and Ice versions are made here in my kitchen.

Other lengths: see above. You can make one longer, though it takes a few days to check your angles. You can make one without a detachable headshell. Does a 12" arm "blow away" a 9.3" arm? No, not really. The sound of the arm will have more to do with the primary resonance, along with other rattles, hums, rings, and so on. The primary resonance frequency of the Abis is low. When the primary resonance frequency is higher, like that of the SME V (1KHz?), it is more easily excited by the higher velocity (or is that amplitude) of higher frequencies. So, if the resonance frequency is 500 Hz, it will be less likely to be excited than if the resonance frequency is 2KHz, where the relative levels are much higher. You know "needle talk", or the signal fed back into a tonearm? That always excites the primary resonance frequencies of all tonearms (and secondary rattles and such). There's no such thing as a resonance free cartridge (would have zero output), or a resonance free tonearm (which material has zero resonance that is practical for a tonearm?). So, higher mass, and lower resonance frequency dominate the sound of this arm.

[MylesBAstor]

Thanks Philip!

[Rust]

But, 99% of the people that ask "when are you going to make one of magnesium" are never going to buy an arm. They sit around on forums, like Monday morning quarterbacks, saying how they would make it.

Don't talk like that, my scotch almost came out of my nose.

But just out of curiosity, what would magnesium bring to the table aside from decreased mass and additional flammability?

[Mockingbird]

SME IV is aluminum (Lord Albert U. Minium, OBE), I believe. SME V, V-12, V... I think anything starting with Roman numeral V is magnesium.

SME site page for IV notes: "Unique one-piece pressure die-cast tone-arm utilising the advantages of magnesium, replaces conventional fabricated construction." which is less than definitive. cf. http://www.sme-audio.com/tonearms/sme-series-iv-tonearm. Reviews claim: "One-piece pressure die-cast tapered magnesiun arm pipe ... ..."

[Mockingbird]

Thanks.

[Billy Shears]

[ochremoon]

Hello all. This is my first post here. Has anyone heard both the Abis 1.2 and the SME M2-12R? I was going to buy the latter but then heard about the Abis and I'm intrigued, especially after reading Art Dudley's review. I really wanted a 12" arm for low compliance carts, but I suspect the Abis may sound better than the SME. The turntable is a Jean Nantais Lenco Ref Mk 2.

[Mockingbird]

I set up one of Nantais's Lencos for a customer in Abilene. Very nice plinth. The armboards are especially well made.

The Abis has a much lower "natural resonance frequency"* than the SME. So, if you put a somewhat bright or thin sounding low-compliance cartridge on the Abis, it will help things out by NOT contributing to the brightness, and the mass of the Abis lowering the resonance frequency of the cartridge/arm combination. I think the bearings in both arms are of similar quality. Build quality of the new M2 seems a lot better than the old 3012 (to me).

*Natural resonance frequency being the resonance frequency dictated by the type of material, the mass, and the shape.

[ochremoon]

Thank you for your response Philip.

[Mockingbird]

You are welcome.

[MylesBAstor]

Hello all. This is my first post here. Has anyone heard both the Abis 1.2 and the SME M2-12R? I was going to buy the latter but then heard about the Abis and I'm intrigued, especially after reading Art Dudley's review. I really wanted a 12" arm for low compliance carts, but I suspect the Abis may sound better than the SME. The turntable is a Jean Nantais Lenco Ref Mk 2.

Welcome to the board!



Philip/Mockingbird is the distributor and he's definitely the one to answer your question!!! I sent his a note and sure he will reply.

[ochremoon]

Welcome to the board!



Philip/Mockingbird is the distributor and he's definitely the one to answer your question!!! I sent his a note and sure he will reply.

Thanks Myles