Tonearm Advice Please?

[karma67]

A friend is looking at purchasing the Revolve Turntable and is unsure of arm options.

I have been as helpful as I am able but am a bit out of my depth at the top-end of the turntable/arm market. Please could the PFM collective make some suggestions?

A link to the turntable in question - www.soundsnatural.co.za/index.php/revolve-turntable-project/

Thanking all in advance.

Regards
Peter

for that money id want all those stuck together bits of wood veneered over,who makes it? oak furniture land?

 

[Thorn]

In fact....I watched 'some like it hot' last week on our blastfromthepast evening. It was crap (barring Jack Lemmon who was great) and Monroe?
hmmmmm.

Oh you of little taste! It's one of my top five films.

 

[Mike Reed]

I hope that's clear now!

Thank you, Sonddek. I follow your text, but it is not quite as apposite to my question as you may think. You are, it appears, discussing the pros and cons from the p.o.v. of a designer/manufacturer. That a thick arm-tube would be better than adding a 'lump of blutak' is undisputable, but does not address the specifics of my questions:

Are there any performance downsides in adding weight at the head=shell end to increase the eff. mass of an existing arm? Also,

Would a, say, 5g weight on top of the headshell (a washer, e.g.) equate to adding that amount to the mass of the arm? Maybe there are mathematically assessed trade-offs here, esp. with the 12" arms I have, as one is adding mass at a relatively small point on the arm-tube.

In my situation, where a low compliance cart. would potentially be my next acquisition, and to fully utilise my current Koetsu (unused for 3+ years), a low mass arm would serve no purpose. My current arms at around 14g each, if increased by the 'Blutak' approach, would at least give me an insight into any improvements which can be wrought from my K., assuming this method would afford the efficacy to serve this purpose.

 

[sonddek]

Thank you, Sonddek. I follow your text, but it is not quite as apposite to my question as you may think. You are, it appears, discussing the pros and cons from the p.o.v. of a designer/manufacturer. That a thick arm-tube would be better than adding a 'lump of blutak' is undisputable, but does not address the specifics of my questions:

Are there any performance downsides in adding weight at the head=shell end to increase the eff. mass of an existing arm? Also,

Would a, say, 5g weight on top of the headshell (a washer, e.g.) equate to adding that amount to the mass of the arm? Maybe there are mathematically assessed trade-offs here, esp. with the 12" arms I have, as one is adding mass at a relatively small point on the arm-tube.

In my situation, where a low compliance cart. would potentially be my next acquisition, and to fully utilise my current Koetsu (unused for 3+ years), a low mass arm would serve no purpose. My current arms at around 14g each, if increased by the 'Blutak' approach, would at least give me an insight into any improvements which can be wrought from my K., assuming this method would afford the efficacy to serve this purpose.

Sorry, yes, I failed to respond to those questions.

The effective mass is generally calculated with reference to the square of the distance of the mass from the pivot, so +5g at the headshell is generally not equivalent to a 5g increase in effective mass. It seems to me the best way to add mass at the headshell is to test resonance with a test record to get it into the 10Hz zone, but you can also do it by ear, tuning it until you are happy that bass response is to your liking.

As regards "performance downsides", mass is mass is mass, so there is nothing theoretically wrong with adding the mass in the form of blu-tac to a strong part of the headshell as far as I can see.

My first customer reports that to his ear his 12.5 inch Blackbird, sporting a Koetsu Red Signature, outperforms his Technics magnesium arm on his SL-1000R, with a Murasakino, and that was also my conclusion when switching between the two playing the same tracks back-to-back, but of course, I would say that, wouldn't I? ;-)

One of the advantages of a low mass arm is that I can cut a longer shaft to produce 10", 11" and 12" arms without mass becoming unmanageable.

In other words I think there is nothing wrong with adding required mass with blu-tac or other non-resonant method to a lightweight arm if the lightweight arm sounds as good or better than a heavier one. Lightness, compensated by added mass, is no obstacle to good performance in itself, and it helps when you want to try a 'low budget' cartridge like an ART9!

I hope that's a thorough answer now but please don't hesitate to ask if there is anything I've missed.

 

[Darren L]

@Mike Reed have you ever tried your Koetsu in either of your tonearms? They might perform a whole lot better than the figures would suggest, having successfully tried a few combinations myself that shouldn't really work according to the effective mass/ compliance calculator on the Vinyl engine. I agree it's not something I would plan on doing but just happened to be what I had at that time.
I've also noticed some after market cartridge fasteners made by Vertere perhaps these may add a little more mass but I'm not sure if that would have a similar effect of using a tonearm with greater effective mass.
I've noticed recently that Audiograil have been using a Groovemaster 12" tonearm with a AS Arche headshell with a stone bodied Koetsu, that would be a quite affordable combo that should work well with your Koetsu.

 

[Mike Reed]

It seems to me the best way to add mass at the headshell is to test resonance with a test record to get it into the 10Hz zone, but you can also do it by ear, tuning it until you are happy that bass response is to your liking.

As regards "performance downsides", mass is mass is mass, so there is nothing theoretically wrong with adding the mass in the form of blu-tac to a strong part of the headshell as far as I can see.

Thanks for that; it looks like a 'before and after' scenario, which only requires a change in the VTF.

have you ever tried your Koetsu in either of your tonearms?

Hi Darren. Yes, I have, but my Urushi doesn't favour the unipivot, much preferring the gimballed arm (PU7). I had my K Black G in my SME Five (which is onlt 11g) and it was fine, but on an Orbe. I did, briefly have the Vermillion on this before transferring, first to Ace Anna then to PU7 at a later date.

Yes, as you mentioned, having a less than recommended mass doesn't mean the cart. is not going to sound good, but if we're talking £3K, £4K and similarly priced cart's, it would be silly not to optimise them.

Yes, the very affordable Groovemaster (my local dealer does them) is probably an effective choice for Ks and possibly (?) Miyajimas at a pinch, but I can't get along with banana shapes and silvery finishes. The latter may now be optional but the former not !!! A 9 inch banana is one thing but a 12 inch quite another !

 

[sonddek]

Thanks for that; it looks like a 'before and after' scenario, which only requires a change in the VTF.

Yes, thanks - I forgot to make that clear. Obviously, as you move the inertia weight towards the cartridge on a Blackbird to increase effective mass, and probably with any arm, you need also to move the counterweight away from the pivot by the right amount to return to correct downforce. The arm's effective mass is increased mostly by the increased distance of the inertia weight (or blu-tac) from the pivot, but also partly by the counterweight moving away from the pivot too.

 

[Darren L]

@Mike Reed I think there is an S shaped arm in the range and they do also come in a rather fetching 'coal black' another perhaps worth considering is the Thomas Schick tonearms, high mass (depends on length and headshell materials) and they come in a variety of finishes, I quite fancy either myself, I like the banana shape, though I've only saw photos, I guess for high mass tonearms above that perhaps Glanz?

 

[Mike Reed]

I guess for high mass tonearms above that perhaps Glanz?

Friend has the middle 12" Glanz (£6 or 7K?); heavy mass of about 30g and well-made, but I couldn't cope with that arm clip. Likewise, the frankly silly arm security of the initial Groovemasters put me right off. They have changed that now. Didn't know about the black one though; must take a look. I'm a bit fussy, Darren; the best arm clip I've had is my PU7 one; a one handed lift, clip and secure in plastic ! My N.A. arm simply has a rest, which is not ideal.

 

[Darren L]

I totally understand @Mike Reed I sometimes think the ergonomics of some hifi components is often overlooked, regarding the Glanz, I couldn't cope with that price.
I see that AO is now doing a 'Ti' version (extra stiff armwand) of the PU7 that comes in a 12" length, apparently the effective mass can be 20g may be just the job for you.