Aro Advice - Dynavector xx2 Mk2 optimisation.

I'm using an LP12/Aro/XX2 Mk 2 with the heavy counterweight on the Aro, with pleasing results. I keep the bias on the mid-range setting (third notch in I think - will have to check), haven't tried it with no bias. You might want to experiment with moving the support post slightly up or down. I've found the best results on controlled bass and soundstage with the arm set for very slightly up at the post end. The other thing to ensure is that the post is not over-locked into position after adjustment(ie. be very light on the allen key - no more than a 'nip' to secure the post). Hope this helps !

Cheers Bob.

I am using the heavy counterweight also. What downforce value are you working to? (on the little ortofon balance that comes with the arrow).

Shall we both remove the bias and compare notes next week?

quote:

What downforce value are you working to? (on the little ortofon balance that comes with the arrow).

You may or may not find the thread link below of some use.


http://forums.naim-audio.com/eve/forums/a/tpc/f/4801938...102935217#6102935217

Is the cart "broken in" yet? Wait until it is before making any major changes surely?

Only about 20 hours in. About ready for a little tweakery methinks!

I have tried the 'no bias' idea on the Aro and struggle to see (hear) how it could be viewed as an improvement. Focus, particularly in the upper to mid bass, is significantly compromised and I much prefer the bias to be at the mid point.

I would try reducing the tracking weight a very small amount.

Hi Simon,

I would agree with Markymark. The bias at mid-point is definitely best for the XX2 Mk 2 on Aro.

Got the Ortofon adjustment device out and it would seem that my settings were previously a bit heavy. Adjusted the set up according to count d's table (thanks for that) with arm level and then raising pillar height slightly after the set-up and it seems to be spot on. I recommend that you set up bias according to the table for the 2g weight (19.61 mN).

Simon,

it's been a while since I ran a Sondek/Aro/XX2, but I recall finding the heavy counterweight rather good at hi-fi and not so great at music, it also led to a bit of bass prominance.

Normal service was resumed with the normal counterweight. I suggest you try this before removing the bias weight (which sounds a bit tweaky to me) and try backing the tracking weight off a touch before you swap counterweights.

Of course, results may vary in differing systems.

Although I have been absent the forum for over a year now, it's interesting how a new crew comes up who are not informed of what happened in the relatively recent past.

The antiskate on the Aro was dealt with at very great length by me, following the brilliant articles written on this forum by esteemed member Mark Dunn (the string started with the title XV1-S, if memory serves me correctly). Do spend a moment to look them up.

To reiterate, I have owned a geddoned LP12 with Aro for about 15 years and have set up and serviced numerous LP12 configurations, at least 5 different ones being with the Aro. I am an exceedingly demanding listener and highly detail oriented in table setup and system setup and I want to assure you and every other Aro owner out there, that if you do not set up the antiskate as per Mark Dunn's wonderful series of articles here...well you are losing the real magic inherent in the Aro. To me, it is sad that Naim has not incorporated these simple changes as standard setup procedure, because they make what is a very very fine tonearm into one that is remarkable almost beyond belief. If you have not done this with your Aro...you really have never heard what it can do.

Last, anyone who says that the Aro sounds better without antiskate is wrong, has no sense of what correct tracking does sound like, and really ought to have a look at an oscilloscope trace of the significant channel imbalance that results.

Happy listening
Scottt

Hello Scottttt,

I've had my Aro for over 15 years. I am familiar with the articles you mention. I have also set up many LP12's over the last 20 years. I just don't post much on this forum (though I did join over 7 years ago) - as I said though, I can't hear what Audio Critic are talking about when they describe the sound as being better without bias.

Hi Scottt and Markymark,

I did once try my ARO / XV1 without bias... just to see.

It was ugly.

Best Regards,
Mark Dunn

PS. Scottt, thankyou for the kind words.

Unfortunately Mike Dunn's important post appears to have been deleted. I believe I have a copy of it somewhere if peeps have trouble finding it.

Proper ARO setup results in blu tack at least one of three places, on the bias weight, fine tuning of the modified or removed azimuth weight and to hold the fishing line in place.

Prominent bass is too much negative VTA and/or too high tracking weight. I find it helpful to dial in the recommended tracking weight with level VTA (use the spirit level that comes with the ARO), then mark a line on the counterweight at the top. Then turn the counterweight either side of this position to get the right tracking force by ear. I have never known it to need more than a half turn to dial in the correct weight.

It's not deleted--try here.

Thanks aht, spent 20 minutes looking, doh.

Sorry Mark in my hast put a typo in your name.

quote:

Originally posted by JeremyB:
Proper ARO setup results in blu tack at least one of three places, on the bias weight, fine tuning of the modified or removed azimuth weight and to hold the fishing line in place.

A lighter azimuth weight from naim would be a good option.

quote:

Originally posted by Emil F.:

quote:

Originally posted by JeremyB:
Proper ARO setup results in blu tack at least one of three places, on the bias weight, fine tuning of the modified or removed azimuth weight and to hold the fishing line in place.

A lighter azimuth weight from naim would be a good option.

Here is what I find - Posted Wed 18 October 2000 !!

wicle: "I am using a Dynavector XX1L on an Aro. The small azimuth counterweight is at the end of it's post and could use a little more correction. I am aware that Naim makes a larger arm counterweight for setting tracking weight on heavier cartridges such as this one, but what is recommended for the azimuth? I am sure that this has been written about before, but the search routine does not seem to work in this new format.

Mark Dunn : "Firstly, the main counterweight's stub isn't uniform in its weight distribution. This is due the little knobbly thing that engages the thread inside the C/W. Thus, a gentle twist of the stub in the right direction may cure your problem."

In my case with vdH Conor it works! I am back with original azimuth weight in center of it's post and I can precise adjust it.

Best regards

Lyubo

A little on the Aro azimuth weight...at some time Naim was offering a lighter one for those who asked their dealer to request it.

I have excellent results using an ordinary brass nut, which weighs a little less than the azimuth counterweight, and is held in place by a small section of a plastic straw, between the nut and the horizontal weight carrier, so that it can be moved left or right, with light resisitance, to position it for accurate azimuth. I have never found a cartridge which did not improve when this lighter weight was used, ie. permitting much finer azimuth setup.

Blutak should be used only as additonal weight for the antiskate weight, as per Mark's articles...it has not been required to keep the thread in the first notch, for me. Should a user find that it is jumping to the second notch, I do believe that a tiny piece of tape would do the job, with less damping.

oNe can even avoid the blutak entirely, as have done by using the appropriate tiny brass washer as a substitute, slipped over the nylon filament, and resting on top of the weight, held in place with a drop of paint/glue. Do note that this brass washer must be identical to the weight of the blutak it is substituting for, and yes they do come in several different sizes, ie weights...and yes I do prefer slightly the sound of brass weight to blutak weight, but considering that it is suspended by the monofilament...this is a very nuanced difference...perhaps 5%, whereas the recalibration outlined by Mark, when done accurately, is a very significant improvement over the "stock" set up.

Happy listening,
Scottt

Wow!

Thanks for all the replys. I understand the need to optimise azimuth, get the arm raised fractionally, back off tracking forces, minimise torque on the arm height bolt and ensure cable dressing is optimised.

The contentious areas appear to be:

Heavier mass counterweight - It was my understanding that this would be the better option.

Mark Dunns mod to reposition the bias location and to compensate for the change by adding mass to the bias weight and shifting the bias hook onto the first groove position.

Obviously I am keen to squeeze the very last ounce of performance from my vinyl so if this is the way to go then that's what I will do. In terms of a correct order I assume I would do this 'mod' first followed by arm height, azimuth and then finally minor counterweight adjustements. Is there a trick to bending the bias piont accurately?

I like the idea of the best possible performance but pliers and blue tack feels a tad worrying!!

Hi Simon,

Re:


"Obviously I am keen to squeeze the very last ounce of performance from my vinyl so if this is the way to go then that's what I will do. In terms of a correct order I assume I would do this 'mod' first followed by arm height, azimuth and then finally minor counterweight adjustements. Is there a trick to bending the bias piont accurately?

I like the idea of the best possible performance but pliers and blue tack feels a tad worrying!!"


I think it's easiest to do the bias mod last. This is because the monofilament line that holds the bias weight has to be as horizontal as possible as it runs between the grooved rod and the bias hanger. If you change the arm height after the bias weight mod you'll end up having to tweak the position of the bias hanger a second time.

Don't use pliers to adjust the bias weight hanger as I'm sure it will mar the surface. Fingers should be fine. Don't forget that you'll need some kind of light weight balance (like a stylus balance) to get the mass of the bias weight + blu-tack to approximately the right point before fine tweaking.

Just to reiterate (so we don't lose sight of the mod's purpose), what the mod does is to more closely match the bias requirements of the stylus across the playing arc of the record. What this means is that the difference in music quality between the 'best' points of bias force agreement (with the ideal) and the 'worst' are made much, much smaller, which leads to more consistent reproduction across the whole playing surface. The mod isn't perfect, but it gets the bias force requirements *a lot* closer to where they need to be.

Best Regards,
Mark Dunn

Hi all,

Just as a follow up to my previous post, here's something I've been playing around with for the last couple of months. I haven't posted about it before because I like to make *really* sure I have my ducks in a row so that I don't take ARO owners on a wild goose chase.

I think we all understand that in a perfect world, when playing a record, the stylus would be at 90 degrees to the record surface, the generator system in the cartridge (whether it be mm or mc) would be perfectly aligned, the plane of the headshell would be precisely parallel (or coincident) to the plane of the arm bearing, and that the turntable would be absolutely level. Naturally, small manufacturing errors usually prevent this from happening in the real world.

We also need to accept that the tools we use for set-up will have some small inaccuracies too. I'm thinking here specifically of the bull’s-eye bubble levels (like the one supplied with the ARO) that we use for leveling.

After cogitating about the mechanical set-up of a unipivot arm it occurred to me that the lead out wires that come out from under the ARO's bearing cup might be pulling the arm to varying degrees as the stylus traces its arc across the record. I used the ARO's bubble level, centered on top of the bearing housing, to check this and sure enough the wires were causing the arm to rotate (as viewed from the front) slightly between the beginning and end of a record side. This is fairly easy to fix by teasing the wires into a position where it doesn't happen. It's a pain in the backside but does lend a bit more consistency to reproduction across the playing surface (but nowhere near as much as the bias mod).

Anyhow, this got me thinking about the factors listed in my second paragraph, above. I decided to try to determine if I could get any improvements by very slightly rotating the arm (as seen from the front) and thus altering the angle at which the stylus contacts the groove walls. My findings are as follows:

1. With my TT set-up (Armageddon, LP12, ARO, Dynavector XV-1) the change in sound quality is very easily heard even before the meniscus of the bubble in the ARO's level 'touches' the etched black circle on the level.

2. The effect of the change follows intuition (well, mine at least). With the stylus 'pointing' more towards the outer groove (right channel) the RH channel gets slightly more detailed while the LH channel gets a bit wooly. Naturally the opposite occurs with the stylus pointing towards the inner groove.

3. My set-up sounds best with the arm rotated anti-clockwise to the extent that the edge of the bubble's meniscus in the ARO's level is *just* touching the inside of the etched black circle.

4. The improvement in musical involvement (and hi-fi sound) with the sweet spot dialed in is very, very obvious. Music has more life, treble is smoother but with more sparkle, bass is slightly deeper but far tighter, imagery is better and is far more solid both side-to-side and back-to-front. Plus, I can play considerably louder and it's a lot of fun to do so.

5. Getting a unipivot arm set-up 'just so', so that it produces its best and with repeatable, consistent results is an annoying long term exercise, but nonetheless rewarding.

Sorry if I've rambled.

Best Regards,
Mark Dunn

Hi Mark,

I just tried it and I believe you are on to something. I found the difference between meniscus touching right inner side of black circle and meniscus touching left inner side of black circle is huge in terms of azimuth weight position and or amount of added blue tack.

This just solved a huge problem for me as I was trying to do achieve the same result using the bias weight as is normal procedure with cardanic pivot arms and even thought I was going deaf in one ear.

This is very exciting. I just realised I can go back to the original azimuth weight with the plastic insert end pointing away from the arm and it just happens to be spot on when pushed all the way on to the spigot. A much more stable set up than the blue tack on a filed down weight.

Mark

Thanks for taking the time to explain your findings. The bias correction tweak makes a great deal of sense so I will give it a go.

I will carry out all the tweaks over the next couple of evenings. Magic really is in the details!!

ATB

Simon

On my Aro/Kaitora Rua, to get the bearing cup level, the azimuth weight is right near the end of the adjustment bar (away from the bearing cup). However, when I read old posts regarding the azimuth weight position, everyone seems to have theirs next to the bearing cup and in fact people want lighter weights. Is this normal for the Rua?

Thanks Mark, for a lovely illustration of an excellent set-up tweak for the Aro. The degree to which the azimuth will require "off" centering from true center will be dependant to a greater or lesser degree on the trueness of the stylus/cantilever assembly with the cartridge generator. Do keep in mind that the azimuth adjustment that we are talking about is approximately 1 degree- this is indeed fine adjustment.

Last...with over 10 differernt cartridge types on 5 Aro equipped LP12 tables, I do not think that I can recollect a single instance where the supplied bias weight was not at the end of its travel on the right, which is why I believe it is too heavy and a better adjustment of azimuth can be had using a lighter weight as I suggestted previously.

As I have said before, the full potential of the Aro is seldom realized unless the owner is prepared to take great attention to the set-up, but if this condition is met (or the person who does the set-up is so motivated), the Aro can deliver a performance which is remakable.

Happy listening
Scottt