Acutex 312 Stylus info?

Madskaman said:

I just received my 312 today! As far as first impressions... This cartridge is warm. Certainly much more so than my Denon DL-110. The surface noise is reduced, and so are the highs. The bass is tight for how much there is. I'm surprised because in my experience, the bass comes as the cart brakes in. It has a very listenable and unfatiguing tone, however I do hope it brightens up a tad once it's broken in. I have it loaded at 47k into a NAD 1020 pre with the tail down tracking at 2.0 and still experimenting.

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You might try backing the VTF off a bit to around 1.8 or 1.9 (where I am with mine now). Also try setting the cartridge flat (works for me), then tail high if you're still not happy with the balance. A tail-down setup has a tendency to increase bass and suppress highs. So does increased VTF for the same reason (both reduce SRA).

John

Yeah with the denon you'll probably want to use a thinner mat to give you more VTA/SRA adjustment range. The stock denon one is quite thick.

The shibata-like stylus on this cart is more sensitive to VTA adjustment, so having it tail down will increase the boomi-ness of the bass and muffle the sound of the hi end.

I removed the thick rubber mat and replaced it with a thinner carbon fiber one. There it is! I'm loving this setup right now. It's at 1.90 and very slight tail up. Thank you for the suggestions.

Madskaman said:

I removed the thick rubber mat and replaced it with a thinner carbon fiber one. There it is! I'm loving this setup right now. It's at 1.90 and very slight tail up. Thank you for the suggestions.

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And it gets better! Glad you found a setup you like.

John

Madskaman said:

I removed the thick rubber mat and replaced it with a thinner carbon fiber one. There it is! I'm loving this setup right now. It's at 1.90 and very slight tail up. Thank you for the suggestions.

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:guitar:

So I pulled the trigger a while back, but the cart hasn't arrived yet and I'm impatient! How good you think this cartridge is (312 LPM III STR or whatever...) ? Apparently the tri-magnet system makes for impressive channel separation figures at least. The tip I believe is a bonded line-contact type? According to some numbers I've seen, it seems to be a 'short' line-contact type, akin to hyper elliptical or what Ortofon call 'fine-line' ie. their '30' or Bronze stylus (except the Ortofons are nude).

I know I will find out soon enough, but what do you think, does the Acutex hold a candle against Ortofon VMS30 which I have currently mounted and which has a really beautiful nude square shank fine line stylus, any bets?

The Ortofon must still be breaking in I suppose, I've listened to less than 10 album sides with it, but so far it's awesome. I've got the setup only 'in the ball park', I meant to fine tune the VTA and alignment since line contact types are supposedly sensitive to it, but this sounds too good to fiddle with.

So, the stylus profiles should be pretty similar, except other is bonded and other nude. Ortofon is MI design and the acutex IM ... I'd really like for the Acutex to give the Ortofon a run for it's money, because the knowledge that VMS 30 styli are virtually unobtainable and over my budget unless I happen to stumble into another superb deal... getting into the ball bark in performance for less than 60 euros would be pretty awesome... I'll let you know what I think once the cart arrives

I guess you'd have to hear from someone who has been able to compare them back-to-back but you have to bear in mind that, at a time when the M312 III STR was #3 in Acutex' lineup, the VMS 30 Mk II was Ortofon's top MI cartridge. Does this sound like a fair comparison to you?

I think the right opponent for the Ortofon would be the M315 III STR, #2 in Acutex's 1980 line. Like the VMS 30, it has a nude square shank tip. Other specs are similar as well with the Acutex having the edge in channel separation. It should be an interesting shoot-out.

Actually, looking at the specs for the 312, it looks like it might give the Ortofon some competition. So, rather than you asking us how the Acutex stacks up against the Ortofon, why not tell us?

John

boreas said:

So, rather than you asking us how the Acutex stacks up against the Ortofon, why not tell us?

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Well, I received and installed the cart yesterday, only listened to a few sides with it this far and my first impression is... you were right, it's an unfair comparison While the Acutex seems like a nice enough cart and a bargain at the going price on eBay, the Ortofon VMS 30 is in another league - I think the stylus is just that much better, the Ortofon is an awesome tracker.

To be fair, maybe the Acutex needs some more breaking in, also haven't optimized the setup much, but as it is I believe it's already better aligned than the Ortofon - I heard it's fussy about such things so I was very careful, while the Ortofon setup was just something quick to test the cart, but it worked so well I have yet to bother trying to get the alignment absolutely spot on.

I'll give it some more time and update if need be... I also have some plans to record clips with both carts. Btw. the turntable is a Telefunken S-600 (which comes with a Ortofon AS-212 tone arm) - both headshells are some cheap affairs and I think both carts would benefit from lighter and better head shells, but this is what I've got at the moment.

I bought a Acutex 312, a 412 and a 415 in the early spring this year.
None of them tracked reasonably clean under 2.2g VTF.
When " breaked in" they are pretty good in my humble opinion
but not any killers. Setting the VTF under 2.0g is not a good idea,
my ones tracks now between 2.1 -2.4g.

The channel separation for my(and others) 312 is a bit lousy at
about 16-18 dB. The 412 and 415 is better at about 25-30dB.

Lars

What would it (the M312 II STR) sound like on a heavy arm like the tp16 of my thorens td160?

miljoneir said:

What would it (the M312 II STR) sound like on a heavy arm like the tp16 of my thorens td160?

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I was wondering that myself after reading muovimies' impressions of the M312 III STR on his Ortofon arm. That arm appears to be a little on the heavy side and most of us who enjoy these "LPM" cartridges have been working with arms on the light side of mid-mass. Also, the compliance specs for the LPMs would seem to indicate that they would not fare well on a heavy arm. On the other hand, our "real world" experience, indicating that the cartridges work best at VTFs of 2 grams or more, makes those compliance figures somewhat suspect.

John

good point...the anomaly of a 'lowest possible mass' cartridge with a tracking force range of 1.5 -2.5gm appears a bit odd...although , if the suspension was stiffened up to compensate for a shorter cantilever...then it begins to make sense..less deflection under dynamic load and a more consistent SRA in actual use...:scratch2: just a wild guess.
The various tri-pole bricks before the lmp re-design seems to have an optimum tracking force around the 1.7-1.8gm mark...give or take a bit of fine tuning by ear...and although i haven't compared the cantilever length difference between the llate 70s bricks and the early 80s lmps..perhaps that might be another factor in the higher tracking forces that seem to accompany good sound with the later variants ?.
:scratch2::scratch2:
just thinking aloud really..this thread is excellent:thmbsp:

Even though they were made later, the 'Texen remind me of the first-gen CD-4 cartridges like the AT12S and the Pickering uV-15, with VTFs hovering around 2g or slightly less.

melofelo said:

good point...the anomaly of a 'lowest possible mass' cartridge with a tracking force range of 1.5 -2.5gm appears a bit odd...although , if the suspension was stiffened up to compensate for a shorter cantilever...then it begins to make sense..less deflection under dynamic load and a more consistent SRA in actual use...:scratch2: just a wild guess.
The various tri-pole bricks before the lmp re-design seems to have an optimum tracking force around the 1.7-1.8gm mark...give or take a bit of fine tuning by ear...and although i haven't compared the cantilever length difference between the llate 70s bricks and the early 80s lmps..perhaps that might be another factor in the higher tracking forces that seem to accompany good sound with the later variants ?.
:scratch2::scratch2:
just thinking aloud really..this thread is excellent:thmbsp:

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Even among the LPMs cantilever length varies. Among my tripoles, the best endowed is the M312 III STR, followed very closely by the 412 STR. The M210 II is noticeably shorter, poor little fella. The cantilevers on my YM308 "brick" and YM320 short-nose are quite similar to one another and they, in turn, are the same length as the M312 III STR.

John

Ok, I call BS on the Acutex compliance specs - either that, or the stylus suspension has hardened quite a bit over the years, but I suppose the tracking force range of 1.7g - 2.3g speaks it's own language. (I don't know the physics and materials well enough, but my gut feeling is tracking force and compliance don't necessarily go hand in hand, but in this case they seem to do so. )

I recorded Side 4 of Mingus at Antibes today - not because it's particularly good for judging cartridges, quite the opposite actually since it's a live recording of an early 60s gig, with even some tape distortion and saturation at points etc. and the pressing is from the oil crisis era, so it's one of the thinnest records I have, but I know it well and I already have recordings of it with different turntables and cartridges.

What the recordings show is with Ortofon VMS 30 the resonance frequency is at 7 hz, so a bit on the low side but within acceptable limits (depending who you ask...). Specified dynamic compliance for VMS30 is 22µm/mN - Resonance frequency with the Acutex M-312 III STR is 12 hz, so at the upper range of acceptable. Specs for Acutex tell 24µm/mN, while in reality my specimen's is more like 10µm/mN ... that's a bit of a rough estimation, but in the ballpark.

Ortofon was tracked at 1.3g and Acutex about 2.3g, it seems to me the optimal range for my Acutex with that tonearm at least is somewhere between 2g - 2.4g ...
Only around 10 album sides have been played with the cart, I hope the suspension will break in some more and increase the compliance a bit.


Bear in mind these figures are based on doing a spectral analysis on the run in groove of the recording, so it's not like they are highly reliable, but they supported everything I've seen and heard with both carts this far.

As for using the cart on a TP16, as it is, at least for my Acutex the TP16 wouldn't be too heavy at all.

I find this interesting, either I got a lemon or these things break in significantly - or everyone who's got one from the Italian seller have a stylus like mine and are running theirs with way too light arms that put the resonance frequency on the audible range, boosting and messing up the bass.

Some more listening impressions while I'm at it - increasing the tracking force from the 1.7g I started with to 2.1g was a significant improvement. 2.1g vs 2.3g not much difference really, nothing that I noticed on a quick listen. The sound is definitely on the 'warm' side, yet the treble is a bit harsh and metallic sounding at times on my equipment. Sound stage is rock solid.

Muovimies, you're far from alone in suspecting the Acutex compliance specs. Much has been said about that in the various Acutex threads. Also, most of us have settled on a VTF quite similar to that which you have. (I'm at 2.0g.) I don't think you'll get much argument from any of us regarding those topics.

As I mentioned in another post, most of us reporting favorably on the M312 III STR are using them on arms that are on the light side of mid mass, not light arms as you suggest, and one of the particular characteristics that gets high marks is, in fact the bass. I don't know on what you're basing your suspicions on but my own experience and that of others (of which I'm aware) would seem to be at odds with your various hypotheses.

So, what sort of mass would you consider too light for this cartridge? Also, do you happen to know the effective mass of your AS-212? I couldn't find that information but, just from looking at it, it appears to be on the heavy side. I realize that looks can be deceiving but it did make me curious.

It's worth noting that Acutex offered a modular headshell called the Saturn V with the 200 and 300 series. (Not sure about the 400s.) By itself, the Saturn V weighs a whopping 5g. There is also a 5.5 g accessory weight included with the headshell. The cartridge itself, minus the 1/2" adapter, weighs 4.25g, meaning that the assembled cartridge and headshell would weigh either 9.25g or 14.75g. This suggests that Acutex, at least, envisioned this cartridge being used on tonearms covering a wide range of effective mass.

[EDIT] I should also add that I have a Saturn V but don't use it. The reason is that the headshell doesn't hold the cartridge securely and, after a few sides, the thing starts to resonate like crazy. It has also been reported that, in some cases, the stylus doesn't seat well on the cartridge, causing the same sort of resonance I experienced with the Saturn V. It occurs to me that this might well be the source of your displeasure with the 312. I've heard of people solving the problem by "Super Gluing" the stylus to the body but that strikes me as extreme. With my Saturn V I firmed up the fit between cartridge and headshell with a couple of little pieces of Blu Tack, one on either side of the cartridge. Maybe you could do something similar with your cartridge. Also, make sure that the screw which clamps the 1/2" adapter around the cartridge body is snug.

John

boreas said:

So, what sort of mass would you consider too light for this cartridge? Also, do you happen to know the effective mass of your AS-212? I couldn't find that information but, just from looking at it, it appears to be on the heavy side. I realize that looks can be deceiving but it did make me curious.

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One spec I found for effective mass (without cartridge) was 12-18g (depending on the position of counterweight). http://ortofon.com/images/stories/tonearms/AS212/AS 212 MkII.jpeg

Also somewhere it was said the arm was designed for use with the Ortofon VMS range of cartridges, of which the upper models were quite high compliance - this information doesn't come from Ortofon themselves though, but does make sense. The Telefunken S-600 has this arm and a Shure V-15 pre-installed. Getting a 7hz resonance freq with the Ortofon VMS30 would make the total mass 20g, 5g of which is from the cartridge, so 15g.

With the compliance of my Acutex, anything less than 20g (including cartridge) would start to get too low and push some of the resonance peak over 20hz. With my setup I get 12Hz resonance frequency, which would make the Acutex compliance about 10µm, which is a far cry from the 24µm spec.


I might come off as displeased with the cart, but I think most of that comes from the fact I put it against the VMS30 from the get go - a bit harsh, but I wanted to judge this cart against the best I know. It's definitely a keeper though, just not sure yet where I'll end up keeping it I'll give it a good break in, a good excuse to keep spinning vinyl and then maybe try it in some different arms. The tinkerer in me wants to get that suspension up to original spec if break in doesn't do it, maybe a drop of dishwashing soap would help... :scratch2:

Mine has always been used on the JVC QL-Y7 which has electronic damping in both planes. It tracks great at 1.8 gr and has never shown any signs of stridency. It's next stop will be the JVC QL-F6 which has fluid damping in both planes and I expect it will act the same.

I very much like this cartridge on rock, pop etc. but for jazz it's voicing in my setup is a bit harsh - saxophone and trumpets etc. sound a bit overly piercing.

I also did one more comparison, against Ortofon D10e, which has a compliance of 15µm, putting the resonance frequency in my setup at 10Hz - so taking into consideration the fact that the headshell I have my Acutex mounted on is couple grams heavier, it seems my original estimation of dynamic compliance around 10µm/mN is pretty accurate.

If there happens to be anyone who knows the mass of their arm and has the ability to record their vinyl setup to computer and analyze it using Audacity or similar audio editor, it would be great if you could check where the resonance peak is in your setup. What you need to do is record either the drop-in groove or silence between tracks and do spectral analysis on it, the resonance peak will be obvious. I'm trying to figure out if these NOS styli are all like mine, or if I have a specimen which has hardened more than most for some reason.

I'm guessing 'new old stock' could actually mean that the cantilever is attached to 30 year old rubber..(or whatever polymer thingy they use to make it wiggle) in which case...maybe we can finally test the 'break in' myth with these tri-pole veterans..