How to align cartridge on a Dual 701?

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funckdren
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How to align cartridge on a Dual 701?

Post by funckdren » 13 Jul 2019 13:12

I recently bought a Dual 701, which came with a Shure V-15 III. This turntable sounds terrific (with impressively low wow & flutter) but I’ve noticed some inner groove distortion on a few records. The stylus is new and clean, and so are these LPs, so I started digging around on ways to deal with this. (I should say at this point that I’m a little bit new to vintage turntables, so please forgive me if these are newbie questions!)

From what I’ve learned, the first thing to check is to make sure my cartridge is aligned properly. In one of the attached pictures, you can see that it does seem slightly off. I’ve read many threads and watched some online videos of people loosening the small bolts and slightly twisting the cartridge to make it parallel with the protractor lines, but when I removed the cartridge sled on my 701, I see that there *are* no bolts – it’s just sort of clipped in. This leads me to believe that making the cartridge parallel to the lines on a protractor is not relevant on a 701? The headshell on the tonearm is angled, so I guess Dual has already “fixed” the angle?

The owners manual says to use the Dual stylus gauge to set “the correct overhang position for minimum horizontal tracking error.” But even if I find one of these Dual gauges (I see some aftermarket ones on eBay), I can’t even figure out how to set the overhang position if the cartridge is clipped in? What am I missing here?

Thanks for any advice.
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lini
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Re: How to align cartridge on a Dual 701?

Post by lini » 14 Jul 2019 12:21

If you have the Dual click-in mount variant of the V15III, and you're using that with an original Shure needle (or a 3rd party replacement needle, that doesn't deviate from the orginal Shure needles in terms of tip position), you needn't align anything - 'cause then it'll automatically be correctly aligned to the original manufacturer geometry.

That the original geometry would rather not be exactly the same as the geometry of whatever protractor you might have applied, is no wonder though. Because not only are there three usual alignment geometries, namely Baerwald/Loefgren A, Loefgren B and Stevenson, but there also isn't just a single one of each of these, but rather an endless number instead, 'cause depending on the chosen inner and outer playback radii, each of these geometries vary accordingly. So even if you'd for example have a table, of which it's known that the original geometry is (a) Stevenson, that would only exactly match up with a Stevenson protractor, if both would happen to be calculated for exactly the same inner and outer playback radii.

Greetings from Munich!

Manfred / lini

Alec124c41
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Re: How to align cartridge on a Dual 701?

Post by Alec124c41 » 14 Jul 2019 13:19

BTW, your picture with the grid does not have the stylus on the crosshairs in the circle. That will throw it off.

Cheers,
Alec

funckdren
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Re: How to align cartridge on a Dual 701?

Post by funckdren » 14 Jul 2019 13:54

Thanks for your replies! Yes, I realize the stylus was not in the crosshairs – I simply posted that picture to show that the cart (actually what we're mostly seeing is the stylus guard) is not really parallel with the protractor lines. But I understand more fully now what's going on.

I guess the ultimate conclusion is if you've got a Dual 701 with a factory installed Shure V-15 III cartridge, there's not much cartridge adjustment to be made, and those adjustments are really not necessary anyway.

Alas, I guess this leaves me with fewer ways to troubleshoot inner groove distortion. I've tweaked the anti-skate lower and increased slightly the tracking force to 1.3g, but it's still there. I know many people rave about the V-15 III, but I'm thinking of trying out a different cartridge as well – an ADC XLM MKIII, which I gather was popular on 701s back in the day. I see lots of people raving about the sound of that ADC cartridge. Some say they prefer it over the Shure.

I did find a few contenders on eBay, one of which has an NOS MKIII stylus, but it's actually an ADC "Omni Pivot Improved" cartridge. Manfred: I've seen a few of your posts about these ADC carts – can you clarify if the Omni Pivot Improved (black body) is comparable to a genuine XLM MKIII cartridge (gold body)? The seller, who seems to know quite a bit, claims they are basically the same cart. True or false?
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lini
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Re: How to align cartridge on a Dual 701?

Post by lini » 14 Jul 2019 14:44

fd: My guess would be, that the vendor most likely combined a ZLM (Improved) body with the XLM (Improved) needle. That shouldn't really make a difference, though.

Greetings from Munich!

Manfred / lini

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Re: How to align cartridge on a Dual 701?

Post by Legrace » 14 Jul 2019 15:19

Even though the cartridge is NOS you may still end up having to replace the stylus. After so many years the stylus suspension can harden up reducing sound quality. Cartridge itself will be OK.

As opposed to making a lateral move cartridge wise you could also consider one of the higher end stylus available for the VIII. Jico's SAS w/boron cantilever is highly regarded and a noticeable step up from the more basic elliptical profile that would have been originally come with the cartridge.

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Re: How to align cartridge on a Dual 701?

Post by funckdren » 14 Jul 2019 15:27

lini wrote:
14 Jul 2019 14:44
fd: My guess would be, that the vendor most likely combined a ZLM (Improved) body with the XLM (Improved) needle. That shouldn't really make a difference, though.
Thx Manfred, So you're saying the cartridges are indeed comparable? I just want to make sure the ZLM body is not a significant step down from the XLM body.

Legrace: Thx for weighing in! Just to clarify, the vendor says the stylus is NOS, not the cart. That's why I'm interested in it...I prefer a genuine ADC XLM MKIII stylus and just want make sure it will sound good on what appears to be a ZLM body. And that's a great thought about upgrading the Jico stylus. I will explore that!

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Re: How to align cartridge on a Dual 701?

Post by Legrace » 14 Jul 2019 15:39

I was assuming they were both NOS. What I was trying to say no worries with the body, might be an issue with the stylus due to rubber aging. Not saying it wont work perfectly, but caveat emptor applies in these situations. The stylus is more important then the body.

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Re: How to align cartridge on a Dual 701?

Post by funckdren » 14 Jul 2019 15:53

Good things to consider Legrace, thanks! I'm looking into boron stylus upgrade for the Shure...$199 is not cheap, but worth it to me if it tracks the end of the record better. Inner groove distortion really hurts my ears.

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Re: How to align cartridge on a Dual 701?

Post by funckdren » 14 Jul 2019 16:04

Legrace wrote:
14 Jul 2019 15:19
you could also consider one of the higher end stylus available for the VIII. Jico's SAS w/boron cantilever is highly regarded
Looks like the boron cantilever is not even Jico's best upgrade for the V15 III. Appears they also have a ruby cantilever for just $50 more. Do you know anything about that one?

https://www.jico-stylus.com/product_inf ... 6dat9lchv1

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Re: How to align cartridge on a Dual 701?

Post by Legrace » 14 Jul 2019 16:47

funckdren wrote:
14 Jul 2019 16:04
Legrace wrote:
14 Jul 2019 15:19
you could also consider one of the higher end stylus available for the VIII. Jico's SAS w/boron cantilever is highly regarded
Looks like the boron cantilever is not even Jico's best upgrade for the V15 III. Appears they also have a ruby cantilever for just $50 more. Do you know anything about that one?

https://www.jico-stylus.com/product_inf ... 6dat9lchv1
Yeah eyeing that one myself. :wink: I once owned a Karat Ruby that had a ruby cantilever and that thing was amazing, zero IGD with that sucker.

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Re: How to align cartridge on a Dual 701?

Post by funckdren » 14 Jul 2019 17:06

Very interesting thread here on boron vs ruby & sapphire, both of which are $50 more:

https://audiokarma.org/forums/index.php ... -r.750299/

All things considered, I'm leaning toward the boron, though your lack of IGD with ruby is tempting...

EDIT: however, that Audiokarma thread seems to indicate that SAS shape is more critical to the sound than the material.

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Re: How to align cartridge on a Dual 701?

Post by Legrace » 14 Jul 2019 18:51

Stylus shape and finish quality of surfaces is indeed paramount. But don't discount the importance of the cantilever. Ruby, boron or sapphire all three fall within a next level grouping, a step up from far more common aluminum. Very likely what you have currently. Its the combination of the advanced shape plus higher performing cantilever material that is synergistic. I actually think the pricing on these is extremely good. To put into context look up Ortofon 2M Black replacement stylus cost.

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Re: How to align cartridge on a Dual 701?

Post by funckdren » 14 Jul 2019 23:59

lini wrote:
14 Jul 2019 12:21
not only are there three usual alignment geometries, namely Baerwald/Loefgren A, Loefgren B and Stevenson, but there also isn't just a single one of each of these, but rather an endless number instead, 'cause depending on the chosen inner and outer playback radii, each of these geometries vary accordingly.
Indeed, I've learned a lot in the last 48 hours...I had no idea there are SO MANY protractor options out there. I've figured out that the original protractor I used (that started this thread) is useless for checking cart alignment on a Dual. Dual utilizes Baerwald, which I downloaded this afternoon. It shows my cartridge alignment is dead on.

So now I'll continue to pursue another cartridge or stylus upgrade to squash my inner groove distortion...thanks to all for weighing in. I'll post back once I get this sorted out.
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Re: How to align cartridge on a Dual 701?

Post by lini » 15 Jul 2019 01:43

fd: Actually the ZLM was the higher ranking model - but, the black instead of gold coloured generator capsule aside, the innards of a ZLM improved and an XLM MkIII body would otherwise be just the same.

And I'd partly agree with Legrace, that the XLM MkIII might just be a sidegrade - however, with it being a standard halfinch-mount model you'd at least have the opportunity to deviate from the origininal Dual alignment and try a more inner-groove-friendly one.

Questions:

- Is the needle you currently have on the V15III(-DU) an original Shure VN35E? Because in my view a sharp (= 0.2 mil minor radius) elliptical should already suffice to not have any problems with inner groove distortion - so that an even sharper stylus shape like a MicroRidge/MicroLine/SAS might not solve that problem... (*)

- Is the Baerwald style protractor you've used for checking calculated for RIAA or rather for DIN LP radii? Because the former isn't quite as inner-groove-friendly as the latter would be... (**)


Well, and regarding your question about the SAS variant with ruby cantilever: As such ruby/sapphire/corundum isn't a better cantilever material than beryllium or boron, otherwise identical make/style/implementation provided (foremost tube vs. rod and tapered vs. straight as well as, of course, length, diameter and incase of a tubular type als wall thickness).

However, personally I'd prefer the ruby SAS to the boron SAS for its different diamond mount style. I.e., as you can see in Jico's SAS info, the boron version is "glue-on mount" (= diamond tip sitting on bevelled surface at the front of the boron rod, fixed by blob of epoxy glue around it) - while the ruby version is "pierced-through mount" (= diamond tip sitting in a hole through the ruby rod, glued from the back end of the shank), which doesn't only look nicer (as the tip isn't surrounded by such a large blob of glue), but is also more robust.

Greetings from Munich!

Manfred / lini


*) At least unless it would rather be caused by somewhat worn records - in which case a line-contact shape (with equally small or even smaller minor radius) could indeed help due to it's larger major radius providing a kind of "wide tyre effect", possibly allowing the tip to trace not so worn parts of the groove wall above and/or below of the somewhat worn part.

**) Btw, in case you haven't discovered it yet: Try JaS' nice alignment calculator in the "Tools" section - 'cause playing around with that might very well provide you with some more insight regarding the topic of alignment geometries in general and also ease your choice of a more inner-groove-friendly alignment in case you'd go for a standard halfinch-mount cartridge.

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