SME IV versus Audio Origami PU7

[wino2020]

I have a 12 inch AO arm on my Acoustic Signature Storm deck and currently use a Transfiguration Phoenix cart. I have a possible opportunity to acquire an SME IV in 9 inch form. As far as I can see the effective mass of both these arms is the same so a change wouldn’t restrict the possibilities for changing carts. The other technical difference I think is the lack of an azimuth adjustment on the SME.

Does anyone have experience of using both these arms and/or be willing to comment on the differences between the two?

[Beobloke]

That’s a tough one. I would have thought the change will give you ‘differences’ rather than big improvements as both PU7 and the IV are superb arms; just with slightly different sonic characters.

I’d say if you want a step up, then hold out for an SME V but, even then, the differences won’t be night and day as the PU7 really is that good.

Frankly, I’d be inclined to save your money and buy more LPs!

[Vrajbasi]

Having had both I would say they are very different sounding beasts, the pu7 has a wider soundstage and greater sence of air, the sme iv has has more depth and kind of places instruments in order with vice like grip often seen as damped but this control and order does have strong benefits in the context of a suitable system. It all comes down to cartridge and turntable compatibility I have also heard big variations with sme arms some can produce this large sence of scale almost walk inn some can sound rather restrained. I would purchase from a sme specialist who knows the product well.

[DiveDeepDog]

I would have thought the change in geometry would account for different sound too? 12" arms less tracking distortion and more relaxed sound. 9" arms generalised as more punchy and upfront.

The natural competitor would be SME312/V12 if you want to retain the tracking properties? Another option is get a 2nd arm pod and put 9" arms on there...

[Vrajbasi]

I agree I would be looking at a 12 inch sme. The 312s and series V/12 are chalk and cheese the 312s due to its static balance is more dynamic and open sounding a bit like the pu7 12" but with a solid dynamic bass, the series v-12 is darker and richer with and slightly rounder bass. The one i like but have to only buy NOS and almost impossible to source were the last of the 312 aluminium arm tube model, with upgraded bearings this is a magnificent arm indeed it has alot of the great qualities of the classic 3012R but with far greater scale and sense of control with sheer life much nicer than any of the arms mentioned. I might know where one is available.

[wino2020]

Aye it would be lovely to utilise the capability of my deck and have an SME something as well as my AO arm, perhaps with a mono cart in the mix with one or the other, but realistically my budget (or SWMBO’s) can stretch to one only. At least at the moment.

I’ve no experience of SME arms but what I read suggests a V isn’t a huge leap from a IV but that a 312 or V12 might well be, at a price. Though comments from user experience might well paint a different picture.

Tonight amongst others I’ve listened to Lenny Bernstein on piano from 1959 playing Gershwin and Evelyn Glennie from the 80’s and I’m wondering why I want to change anything! Not my usual stuff but bought from my good lady’s charity shop and scrubbed on my Okki Nokki. Such detail on these recordings! It would be great to buy more vinyl as Adam suggests but somehowI need to get down to the 500 most played and keep them rather than buying more!

Nari, I’m intrigued by your suggestion of going further up the SME 12 inch range. I might come back to you in that one.

[Mike Reed]

I would have thought the change in geometry would account for different sound too? 12" arms less tracking distortion and more relaxed sound. 9" arms generalised as more punchy and upfront.

I call it tracing but others call it tracking !:). However, I agree with your take on the difference between 9" and 12" arms (generally). I went from SME Five to, firstly, N.A. 12" Ace Anna, then added a 12" PU7 (I wanted to compare unipivot with gimbal). Admiitedly, the Five was on Orbe and my present two 12" arms are on a Dais.

I would not revert to a 9" arm; partly for that 'sonic solidity' but also for the much improved ergonomics (handling/cueing etc.). Your PU7 will have more eff. mass that the Five (11g), and whereas Johnnie made the arm mass to order in many instances, they're usually around 14g

I have a Proteus on my PU7 and it's a marriage made in Heaven. Moral of this story: stick to your 12" PU7, which is a joy to return and safely clip with one hand; likewise, your Phoenix. Such a pity that Transfig has gone under ! By introducing a Five (let alone a Four), you'll certainly get a more upfront sound, but a more sterile one too, i.m.o. Besides, the mounts are entirely different, and that must be a hassle !

You're hardly in the frying pan but I do suspect you are playing with fire.:)

[wino2020]

Very interesting comments Mike.

I can’t find an online note of the effective mass of a PU7 though the figure of 11g sticks in my mind from somewhere. How can you tell? I don’t recall a figure of 14g from anywhere.

I do note the comment on the AO website that “ the effective mass can be tuned to your selection of cartridges approx. 11 – 20 grams” which I assumed related to cart weight rather than tonearm mass ( though there can’t be many carts which weigh 20g?) but that may be my misperception. My Phoenix weighs about 8g which I think is the same as the Proteus and I agree the combination sounds terrific, though I haven’t tried many on my AO arm. Maybe one day I’ll ask about alternatives.

[Mike Reed]

Peter, when I got my (ex dem.) chromed PU7 I phoned Johnnie and asked him. He was a bit vague, as each is a little different depending on customer requirements or not, as I said. He suggested that as mine was dealer stock it was likely to be around 14g.

I had Lyras, K Black Goldline and Urushi on my Five and they were fine, but the Ks especially shone on the Ace Anna and PU7 understandably. Despite having 11g eff. mass (qualifying as very low medium mass), the SME is very versatile, up to a point. My guess is that by 'tuning', Johnnie meant the eff. mass, not the cart. weight, as that would be handled by the counterweight (which affects mass, of course).

[Vrajbasi]

Peter, when I got my (ex dem.) chromed PU7 I phoned Johnnie and asked him. He was a bit vague, as each is a little different depending on customer requirements or not, as I said. He suggested that as mine was dealer stock it was likely to be around 14g.

I had Lyras, K Black Goldline and Urushi on my Five and they were fine, but the Ks especially shone on the Ace Anna and PU7 understandably. Despite having 11g eff. mass (qualifying as very low medium mass), the SME is very versatile, up to a point. My guess is that by 'tuning', Johnnie meant the eff. mass, not the cart. weight, as that would be handled by the counterweight (which affects mass, of course).

One has to consider that the effective mass of the PU7 will depend on version your Chrome version is a signature version and has a brass arm tube to facilitate the plating process, trying to plate over aluminium in a consistent manner is not a best even though can be done. Even so brass and aluminium sound different.

Aluminium is much lighter for starters also on another note brass is much different sounding to aluminium before the effective mass comes into consideration. Sorry to go slightly of tangent but it was nice to see you have the better of the pu7 arms available in my opinion due to the materials used.

I much much prefer the heavy pu7 as you have, then if we really get into it chrome sounds different to black anodised, as the process is different and you will need copper and maybe even nickel as a under layer.

The plating process changes resonances quite dramatically on a tonearm as resonances are changed if you really want to get into some nutty stuff the Gold plating and Chrome plating sound different I learnt this from my friend who is bit extreme should we say he actually demonstrated how the type of plating and thicknesses change the sound and I have to say its very apparent indeed.

I love this hobby its full of discoveries, with tonearms and turntables we are dealing with tiny resonances that do really affect the sound. Manufacturers tend not to listen to the effect of materials used and how it changes sometimes materials are chosen to make the manufacture process, in some instances they get lucky and actually and stumble on a better sounding product. Of course its rude to generalise some do listen extensively especially the Japanese artisan manufacturers who can be rather anal in such matters. Sorry to waffle on a bit and I know I could be rather boring just nice to see you had one of the nicer sounding and soon to be extinct pu7 versions.

[Mike Reed]

NARI,

Thank you for that; far from being boring, it was quite enlightening, as I'm no metallurgist ! It may well be, then, that my 12" chromed PU7 has a heavier eff. mass than I'd thought. Certainly, my Urushi Vermillion (which has been in a drawer for 2 years!!!!) much prefers my PU7 than the unipivot 12" Ace Anna. I'd put this down to the bearing differences but the Ks do prefer heavier arms, so maybe that's the reason. My previous Benz Ebony (with a bit more compliance) sounded good in both arms, albeit different.

Anal or analgesic? Maybe, but fascinating to a vinyl aficionado.:lol:

[Vrajbasi]

Hi Mike

Thank you

The brass arm pipe will certainly doing its magic too brass is a kinder sounding material overall than aluminium as is stainless, I have listened to materials and been on several listening panels where one could hear clearly the differences of the construction and material. Tonearms are very complex beasts, they are dealing with so many factors.

I recently had an older 3012 r plated in crome over the stainless steel my friend at unique audio helped me on this one, it was shocking to hear the difference.

[WESTLOWER]

I recently had an older 3012 r plated in crome over the stainless steel it was shocking to hear the difference.

HI Nari,
and what was the conclusion to that particular mod?

[Vrajbasi]

HI Nari,
and what was the conclusion to that particular mod?

I was told there was 20 microns of copper and 5 microns chrome and 7 microns of chrome, so there is quite a mix of material each having there own character as each is changing the resonances. The copper is the sofest material then the nickel and chrome is hardest. I found it improved the solidity greatly of the arm massively the arm had greater focus it allowed me to hear deeper in the recordings with more weight to the sound the soundstage was incredible.

[Mike Reed]

Hi Mike

Thank you



My friend at Unique Audio helped me on this one, it was shocking to hear the difference.

I still remember, in a room full of esoteric hifi at Scalford a few years ago, being approached by a friendly chap who seemed to know all about me. Must admit, I was a bit taken back, as I'd had no dealings with Unique Audio, which I think he ran. Thought he was psychic ! Whatever, he knew his upmarket audio and I think he might have had the whole shop there ! His name currently escapes me but I had heard of him.

[wino2020]

I agree I would be looking at a 12 inch sme. The 312s and series V/12 are chalk and cheese the 312s due to its static balance is more dynamic and open sounding a bit like the pu7 12" but with a solid dynamic bass, the series v-12 is darker and richer with and slightly rounder bass. The one i like but have to only buy NOS and almost impossible to source were the last of the 312 aluminium arm tube model, with upgraded bearings this is a magnificent arm indeed it has alot of the great qualities of the classic 3012R but with far greater scale and sense of control with sheer life much nicer than any of the arms mentioned. I might know where one is available.

So as chance would have it, and I’m sure you guys all know about this, a V12 has appeared in the classifieds. Obviously it’s well above the cost of the IV which I could get, and tbh I’m not sure I could stretch that far, up is this really a genuine alternative? Still seems to lack an azimuth adjustment though which I certainly found useful on my AO, even if only from an OCD viewpoint!

[Mike Reed]

It's still an SME and has SME tonal characteristics, though being 12", not as up-front and 'neutral' (sterile?) as the Five. It's also probably a little lighter at 12g eff. mass than your PU7; okay if you stick to medium/higher compliance coils. I looked for one for my Dais (as I had a Five beforehand) but none was available, so went for the chrome PU7; glad I did, and think it's cosmetically as striking as the V12.

Have never needed azimuth adj. on any of my fixed head-shell arms (at least 4/5 since the early eighties). If a real 'on the fly' facility was available, as on the Reed 3P, e.g., I might be tempted to experiment, but doubt it would fixate me for more than a week or two. If the arm mount is correct and the cart' fixing correct, why would azimuth be out? Even if it were, a shim in either position should suffice; crude, but possible.