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LP-12 Naim Aro Owners Please Read

LinnAroMan

New Member
I have been looking at GreenStreet Audio's aluminum sub-chassis for the Aro and they just posted on their website a problem with the Aro armboard made by Linn. They say the arm mounting hole is not drilled in the right place. I just checked my setup and I have the problem they found. On my turntable the distance between the center of the spindle and the Aro pivot point is under 210mm. Naim's website says it should be 212.5mm. Mine is 3mm off!! Is this as big a problem as I think it is? If I try to move the armboard over 3mm it will be too close to the side of the plinth for the suspension to bounce properly. Does anyone else have this problem?
 
Hmmm... interesting. I actually thought that Naim bought blank armboards, machined them and supplied them with the Aro, strange that they are off.
 
I have been looking at GreenStreet Audio's aluminum sub-chassis for the Aro and they just posted on their website a problem with the Aro armboard made by Linn. They say the arm mounting hole is not drilled in the right place. I just checked my setup and I have the problem they found. On my turntable the distance between the center of the spindle and the Aro pivot point is under 210mm. Naim's website says it should be 212.5mm. Mine is 3mm off!! Is this as big a problem as I think it is? If I try to move the armboard over 3mm it will be too close to the side of the plinth for the suspension to bounce properly. Does anyone else have this problem?

Remember there is some play in the armboard mounting on the LP12 itself - it is held on by 3 tiny wood screws and the holes in the subchassis are over-sizeed to allow for movement. Your deck may have the armboard twisted or otherwise slightly out of true.

The alignment issue is a moving target as it all depends upon the distance between the cart mounting bolt centres and the stylus tip - the holes are fixed on the Aro which is IMO utterly insane, one of the dumbest decisions in the history of analogue audio reproduction - a great arm nobbled by stupidity. The result being that it is only applicable for cartridges identical in measurement to the Karma, Troika etc. To align anything else you have to twist the whole armboard as described above.

Tony.

PS Anyone who claims this parameter is unimportant is a liar / idiot / both!
 
"to align anything else you have to twist the whole armboard."

Not if your name is MARTIN COLLOMS!

He has filed out the cartridge mounting holes, and he uses an Aro for all his cartridge comparison tests. I expect that he has his alignments spot on. I always accept his superb cartridge comparison judgements and have saved a lot of aggravation, time and money by purchasing cartridges following his recommendations- instead of following advice from elsewhere.
 
"to align anything else you have to twist the whole armboard."

Not if your name is MARTIN COLLOMS!

He has filed out the cartridge mounting holes, and he uses an Aro for all his cartridge comparison tests. I expect that he has his alignments spot on. I always accept his superb cartridge comparison judgements and have saved a lot of aggravation, time and money by purchasing cartridges following his recommendations- instead of following advice from elsewhere.

That is clearly the logical thing to do, though you'd think Naim would offer it as standard. I notice Loricraft mount the Aro on a nice heavy SME style sliding base which nicely circumvents this design flaw.

Tony.
 
I have suggested to Naim on a number of occasions, that their ARO should be more 'universal' but it's always met with negativity. I don't see why they couldn't mount it on an SME type mount instead of the fixed LP12 board as this would allow easy fitting to more TT's. They wouldn't even have to make it themselves, there are plenty of engineering companies able to knock something up for notta lotta money.

I guess they are still blinkered Linn fans...:eek:
 
I have copies of the original technical drawings for the Aro. On those drawings it states that the mounting distance is 211mm +/- 1.5mm. Therefore, I would say the correct distance is 211mm.

To be honest, I can think of a number of reasons why fitting the Aro to an SME style mount may not be beneficial (it would make cartridge alignment easier though).
 
The question to ask seems to be: “what is the optimum distance for the ARO”.

The Green Street link shows Naim’s spec to be 212.5mm from pivot to platter centre. Green Street relies on Naim for determining the optimum distance, and has not published any independent finding on this.

YNWOAN points out that the original technical drawings specify 211 +/- 1.5. That would seem to indicate that 212.5 is within the original spec. There is a possibility, however, that Naim discovered that 212.5 is optimum and so finalised on 212.5.

At any rate, if Green Street is correct, then ARO owners are likely to find that the actual distance on their units is 209.5 to 210. That would be within the original spec but not within the later published one.

Given what I have posed as the question, it would seem that the answer will come from measuring tracking error at 209.5, 210, 211, and 212.5. This can be done via a computer programme. The programme I used is available on Ebay (tap in CARTRIDGE ALIGNMENT). It is called ‘The Vinyl Alignment Solution’, and claims to give the tracking error product for various distances. I was initially very skeptical that any improvement would result from using this programme- as opposed to a variety of standard protractors. However, after using it I was sufficiently impressed to give details of the results I obtained on another forum, the Vinyl Engine. Use of this programme may be problematic with certain arms; it was with mine, and I do not know whether it will be with the ARO. In any case, there may be better methods of determining the optimum distance for the ARO. It would certainly be a problem to alter distances (easily) for a test unless one modifies the Aro first or uses a ‘slide’, files out the headshell etc.
 
Dear readers,

I have been following developments here for a while regarding the “GreenstreetAudio alternative (affectionately known as the Klone) as described by ex brickie on page 1 of “THE review! Thread.”

Now then, let me state from the start that I have no issue with people like Arthur K, John R or flatpopley with their different and innovative alternatives to either the standard subchassis or the Keel. They give you guy’s choice at various different prices and why not, if you really want to – Just get some demos first!

I also have no problem with people tackling the issue of cartridge adjustment with the Aro. There are differing views as to whether or not to slot the headshell or not. Or to use an adjustable base for the Aro, to achieve the same, or to leave well alone.

Personally, my view is that one either adopts the Martin Colloms approach or sticks to the standard arrangement, as I remain unconvinced on the adjustable base.

So, there are my views and I hope you can see that I am not blinkered to the requirements of the market. Indeed it was I that persuaded Linn to seriously look at the possibility of producing the Keel for Aro. Linn as history now shows, were open-minded to this suggestion and before too long, research into the viability of the Keel for Aro was undertaken.

In order to cut the story short for you and to cut to the quick, I supplied Linn with all the technical information they required on the Aro. These were the original drawings and the dimensions were exactly as YNWOAN has stated already here. I also supplied Linn with two Aros so as they could perform listening tests in order to optimise the musical performance of the Keel for the Aro. The gestation of the Keel for Aro nominally took from May 2008 to November 2008, a considerable time and this reflects the care and attention to detail that David Williamson, the designer of the original Keel applied to the task. I was involved along the way, supplying information when required and offering opinions, advice and where necessary liaising with Naim in order to furnish Linn’s R&D with absolutely the correct information. All in all a considerable amount of work for David in initially designing and then latterly refining a Keel specific for the Aro, and ensuring the final finished product was absolutely perfect for the task.

So it is with some considerable dismay that I read here and also on the GreenStreet website that they are publically stating Linn got it wrong:

QUOTE“If you have an Aro arm mounted in an armboard made by Linn the geometry is likely to be incorrect. e have discovered the in the wrong location.
The specification for the Aro calls for the distance from the center of spindle to the pivot point of the tonearm to be 212.5mm.
If the is tonearm in this location on the armboard it causes the tonearm post to interfere with the triangular brace in the plinth. Linn's solution to this problem seems to have been to move the hole.”


Why did GreenStreet feel they had to copy it? Well doubtless they felt they could make it cheaper judging by their blurb. Well they have failed and I think the best thing they can do is have a total recall and refund their customers.

Here’s why in brief and why I feel it is necessary to post on this thread for you:

Firstly, the 211mm distance is the correct distance from the pivot centre to the platter centre. There is a tolerance of +/-1.5mm on the original drawing and so 212.5mm sits right at the upper limit. So for Greenstreet to publically state this misinformation that Linn is “likely to be incorrect” on their website is entirely wrong IMHO and I feel I am therefore duty bound to publically correct this for you and call for GreenStreet to remove this misinformation from their website and publish an apology.

For the record, the original Naim cut LP12 board as supplied by Naim up until last year is to the central 211mm specification.

The Keel for Aro is to the central 211mm specification and the standard Aro armboard now manufactured by Linn for Aro owners, following Naim’s decision to cease production is also 211mm. All have identical dimensions and are exactly as per Naim’s drawing that I hold on file dated 24/08/88 with the last change for the Aromatic as of 04/06/91.

I any happy to furnish any applicant with my own photographic evidence if this is required, but I am not prepared to publish Naim’s drawings here of course.

GreenStreet to make matters worse, are now suggesting that owners wanting to use their product need to now take a section of the corner brace away beneath the Aro! So maybe while someone is doing this, they can also open out the Aro mounting hole too?

A couple of questions that need asking and my suggested answers:

Have Greenstreet mounted an Aro on this Klone before shipping it out to you guys?
I would venture to suggest that this is very unlikely. Otherwise why are the problems only being discovered now and not discovered before shipping?

So, have they even listened to the product, let alone produced revisions based on findings before shipping to you guys?
Again,I think we can work the answer to that one out!!!!!

Anyway, I hope you appreciate that I do understand that it’s not always possible or desirable financially, to shell out for a proper Keel, but please do yourselves a favour, check out the offerings from Funk or flatpopley first, for at least these guys are capable of original and innovative thought. And please while you are considering your options, do hear a proper Keel, as surprising though it may seem to you now, you may actually find that it is worth the investment after all!

Regards
Peter Swain
 
Peter.

A very well considered post. I think Greenstreet have shot themselves in the foot. They were on thin ice anyway with a blatant copy, but then to say Linn is wrong!

I will arrange a demo of the RubiKon for you when the production version is ready, you might like it :D

Regards

Andrew
 
I have fitted Aro's to LP12's; as stated by Peter above, there is no problem with the pillar of the Aro fouling the corner brace - in fact there is plenty of room.
 
Thanks for your posts guys, I just want interested readers to get a complete picture of what's been going on here IMHO. That's all really.

I just couldn't let go the fact that GreenStreet were blaming Linn for something that they patently had not done.

Kind regards,

Peter
 
Anyone truly interested in the arm geometry should download Seb's calculator from Vinyl Engine and type in the correct numbers to see exactly what difference the tolerance and position makes, especially if not using Linn spec cartridges. Naim have it spot on with their recommended spindle-pivot distance, hitting the balance between start of side and end of side distortion as per Baerwald.

http://www.vinylengine.com/phpBB2/viewtopic.php?t=21499
 
Had this problem with my Gyro se and the Wilson Benesch arm. If you look hard enough you can find virtually any stp mounting distance you like for the WB arm on the internet.
In the end I had confirmation 'from the horses mouth' as it were (215.5 mm) and Mitchell were kind enough to machine me an arm plate with the correct stp distance at no extra charge. I would hope all Baseplates for this combo will be correct from now on !


Best regards,

rr
 
Dear Peter,
We at GreenStreet Audio never meant any disrespect towards you or Linn. We simply cannot understand how Naim can post the mounting distance as 212.5 when it is clearly not the optimal distance. We located the mounting position in good faith using the manufacturer's specifications and assumed Naim was correct and, therefore, the Linn armboard was wrong. Apparently that assumption was incorrect, but I would hope you can see it was not an outrageous conclusion to reach.

We are not a large corporation and are offering a product at a price point that an enthusiastic DYI audiophile can afford. We cannot do extensive testing on every tonearm on the market, so we use the manufacturer's specifications. In lieu of extensive testing we offer the ability for our customers to test it themselves and draw their own conclusions. Our refund policy is iron clad and we will return every dollar including the shipping cost if the customer is not happy for any reason. We are not in competition with Linn's Keel. When you buy a Keel you know you are getting Linn's research and development and it will sound as good as Linn can make it. When someone wants the Linn sound they take their deck to a dealer and have them install a Keel, they don't come to us. Our product is for those who like to experiment, and if their experiment fails we offer a way out. I believe there is room in the marketplace for this idea.

We did not rippoff Linn's R&D as it has been suggested on this form. If anyone cares to take the time to measure our sub-chassis and a Keel they will find significant differences. We based ours on the same pocket pattern because it was an excellent starting point, but that is were it ends. We machined, and drilled, sawed pieces off and epoxied them on. Using my 30 years of mechanical engineering experience and our critical ears, I believe we have come up with a product worthy of a listen for our customers who do not have the wherewithal to experiment with a product as expensive as the keel.

I am modifying our website today to remove the incorrect information. Please understand we had, and continue to have, no intention of spreading misinformation. Our marketing technique of using a problem we thought we had discovered was brash and not well founded. Please find it in your hearts to forgive us, we are after all Americans.
 


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