[roscoeiii]

Hi folks,

I am selling a Moerch arm with its highest mass (14g "blue dot") armwand to fund an upgrade to the Moerch DP-8. I have another couple armwands of less mass, and I am wondering about the need to get another high mass armwand vs keeping costs down and just adding weight at the cart end by using something like the heavy EZ Mount Soundsmith screws to one of my lighter Moerch armwands. With the Soundsmith heavy screws, I can get to right about 14g, the effective mass of the armwand I will be losing. Are there any sonic advantages of doing one or the other (putting cost aside for now)? With a cart that benefits from a higher effective mass tonearm of course (ZYX in my case).

[sebrof]

I can't answer your question, but when I had a Denon DL-103r and a Rega RB300 I stumbled across this tweak to add mass to the arm. Made sense to me at the time, I did it and it did help. I've since moved on from that cartridge.

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1032024188&read&keyw&zzstrange+tonearm+tweak

[WireNut]

I'm just learning about arm and cartridge mass. Don't understand it yet but I'm working on it.

[neobop]

Hi folks,

I am selling a Moerch arm with its highest mass (14g "blue dot") armwand to fund an upgrade to the Moerch DP-8. I have another couple armwands of less mass, and I am wondering about the need to get another high mass armwand vs keeping costs down and just adding weight at the cart end by using something like the heavy EZ Mount Soundsmith screws to one of my lighter Moerch armwands. With the Soundsmith heavy screws, I can get to right about 14g, the effective mass of the armwand I will be losing. Are there any sonic advantages of doing one or the other (putting cost aside for now)? With a cart that benefits from a higher effective mass tonearm of course (ZYX in my case).

Hi Roscoe,
Isn't the DP-8 a more conventional pivot arm, as opposed to the DP-6 unipivot?  The arm wands are interchangeable from one model to the other?  If so, why are you selling the 14g wand?

I obviously don't know much about Moerch, but they have a good reputation and look like high quality arms. I would think that structural rigidity and the possibility of flexing, would be #1 consideration for adding mass to the lighter wand. That might also impact arm resonance - affect unknown.  Also, your changing the center of gravity by adding mass above the headshell.  This might not be much of a consideration on most arms with conventional bearings, but I remember reading about Moerch engineering and design on the DP-8.  Aren't the vertical and horizontal bearings in different planes?  I don't know the impact if any, of changing the center of gravity, but I bet if you asked Moerch they would tell you to get the heavier wand.
Why don't you shoot them an email and see what they have to say. I have the feeling they would give you the straight scoop and not just try to sell another arm wand.
neo
 

[BobM]

I agree - send a note to Morch. They will probably be happy to respond.

(BTW - I have a DP-6 red dot and love it. Only flaw is it doesn't have on the fly VTA.)

[decal]

Here's a two-in-one solution............................... ......

[roscoeiii]

Yeah, based on these comments, I may spring for the armwand.

BobM, yeah I have loved my DP-6. The reason that I am selling its blue dot armwand is that both are gold, and a buyer will want to have a matching armwand and tonearm body. I hear you on the VTA on-the-fly. Before I decided to get the DP-8 (which does have on-the-fly VTA), I was talking with Pete Riggle about getting one of his VTA devices for the DP-6.

[neobop]

I talked to Pete Riggle about making a VTAF for the Sonus Formula 4.  I never used his device and didn't know how it worked, but he was anxious to make one for the arm.  It even entailed extending the platform that holds the cueing device, for lateral stability - guides.  That inspired me to look into it further and it seems unsuited for lightweight arms. My efforts to find more info on the VTAF were thwarted by a friend of his who posts on these forums and I didn't pursue it further.  Before the posts were changed, by request of the OP on Karma, I read about Rega arms falling out of their mount and similar stability problems.

I'm not sure if this was misuse of the product or or what.  It was enough to scare me off.  I'd be interested in further info and suggest you proceed with caution.
neo

[BobRex]

I talked to Pete Riggle about making a VTAF for the Sonus Formula 4.  I never used his device and didn't know how it worked, but he was anxious to make one for the arm.  It even entailed extending the platform that holds the cueing device, for lateral stability - guides.  That inspired me to look into it further and it seems unsuited for lightweight arms. My efforts to find more info on the VTAF were thwarted by a friend of his who posts on these forums and I didn't pursue it further.  Before the posts were changed, by request of the OP on Karma, I read about Rega arms falling out of their mount and similar stability problems.

I'm not sure if this was misuse of the product or or what.  It was enough to scare me off.  I'd be interested in further info and suggest you proceed with caution.
neo

If an arm fell out of the VTAF I'd suspect that either the arm wasn't seated properly or that it was raised so high as to be at the end of the post.  Keep in mind than the VTAF doesn't lock the arm tight, it's snug, but it is possible to lift the arm out of the VTAF.  So, yeah, I'd agree with the misuse.

[neobop]

If an arm fell out of the VTAF I'd suspect that either the arm wasn't seated properly or that it was raised so high as to be at the end of the post.  Keep in mind than the VTAF doesn't lock the arm tight, it's snug, but it is possible to lift the arm out of the VTAF.  So, yeah, I'd agree with the misuse.

That's interesting, do you have one of these?  I get the impression that the arm sits on a number of inverted cones?  In theory that should decouple the arm from the mount.  Most arm designs mass couple the arm to its base with 1 or 2 bolts.  If that is the case, I think it might work better on higher mass arms and housings.
neo

[watercourse]

Neo,

With the VTAF the arm does not sit on cones, in the case of my three-point mount Rega arm, the arm is bolted to a brass cylindrical guide that sits within a heavy bronze bushing that itself sits on top of the plinth. Think of a pipe within a pipe, with very little movement allowed except up and down - you get about a half inch of vertical adjustment. Riggle probably only changes the mounting method to the brass guide, as well as diameters of these parts, but everything else is the same basic design.

I'd have to say the person that complained about the Rega arm falling out either installed it incorrectly, or went beyond the maximum height, and the entire arm and cylindrical guide assembly thus fell out of the bushing. My guess, anyways. One has to wonder about some people, because the adjustments don't happen fast enough to not notice something might be wrong. That said, I don't believe there are any markings on the guide telling you "STOP NOW, YOU'VE GONE TOO FAR!"

I know it's off topic, but I'm excited to be able to answer a question for Neobop once in a while! 

[jimdgoulding]

This is really crude but you could add some Blu-Tak under the arm and play around with that. 

[BobRex]

That's interesting, do you have one of these?  I get the impression that the arm sits on a number of inverted cones?  In theory that should decouple the arm from the mount.  Most arm designs mass couple the arm to its base with 1 or 2 bolts.  If that is the case, I think it might work better on higher mass arms and housings.
neo

From the VTAF website - Installing the VTAF Bushing: "The VTAF™ bushing needs to be installed with a slightly loose fit in a 1.25" nominal hole in the arm board or the turntable top deck."  There are no cones, inverted or otherwise, involved.  The recommendation is to use Blut Tack if you want to secure the bushing.  The only part that is held in place - screwed down - is the guide system.  Everything else floats unsecured.

[neobop]

Thanks Watercourse, BobRex, for your explanations.  I think I now have a better idea of how this works. The thing about the inverted cones was from a pic I saw at a forum.  I didn't realize it was a mod.

"The only part that is held in place - screwed down - is the guide system.  Everything else floats unsecured."  This is the part that concerns me.  In theory it will defeat design criteria on some arms, and is the reason I would have to extend the lifter platform on the Sonus arm - for the lateral stability guides.

I guess you never know till you try it. Many user reports are positive.
neo