Kuzma 4Point Owners: Try This!

[bazelio]

The sapphire pivot cup update for the Kuzma 4Point by Franc Kuzma a year or two back was, to me, an unequivocal improvement. I heard only upside after receiving my upgrade. Now, in a similar vein, @Vienna and I have discovered a modification that delivers another clear improvement to this already great arm. A modification so simple that it can be performed at home in under one minute. Savvas and I independently came to the same conclusion based on the same impressions of the before vs after: this is a no-brainer modifcation that makes the Kuzma 4Point sound like a new arm. A better arm. Savvas commented on increased dynamics. I agreed and also likened the change to an increased sampling rate. I hear no downsides.

The modification is simple: Remove the upper damping trough and paddle bracket. Though I wasn't using damping oil, I have always kept the trough attached. But, it adds mass and serves no purpose in the case where one isn't using it. After removing the trough, you'll find VTF needs to be reset, which means the moment of inertia about the pivot point has changed. Incidentally, I also recommend finding a counterweight configuration that allows for positioning the top weight as close to the pivot point as possible.

 

[Vienna]

To add some notes on this modification:
-the total mass removed is 13.34 grams

- the majority of the removed mass is located about the vertical pivot cups thus the center of gravity is reduced (to an already negative CG Tonearm)
- this mass of 13.34 grams was installed on the right side thus loading unequally the vertical cups
-the VTF after removal was reduced 0.4 grams.

therefore the removal of this mass led to a very noticeable sound improvement due to :

1. The effective mass of the Tonearm reduced; and made a better match with high compliance cartridges

2. The center of gravity lowered thus made the Tonearm less prone to vertical rise (because of the negative CG , the specific Tonearm tends to rise)

3. The moments of inertia reduced

4. The unequally loaded vertical cups are now loaded equally

5. The removal of the trough and paddles means less vibrating elements

p.s. Prior this modification, I spoke with Franc Kuzma , who didn’t find any negative

 

[rDin]

Interesting. Have you tried using the trough with fluid at all to see whether there were any gains to be made before removing it?

 

[tima]

this is a no-brainer modifcation that makes the Kuzma 4Point sound like a new arm. A better arm. Savvas commented increased dynamics. I likened the change to an increased sampling rate. I hear no downsides.

An increased sampling rate? Too bad bazelio you have no context for your claim. Why do you hide your system?

 

[Vienna]

Interesting. Have you tried using the trough with fluid at all to see whether there were any gains to be made before removing it?

I did in the past and the sound is getting very dark .

 

[kodomo]

I will try this and report with my 4 point.

I have used the damping before with cartridges that needed it but as of now with Miyajima Madake I do not need them but they are still on the arm. It is a very easy thing to try so why not.

I am with @bazelio on the counterweight position being closest to the pivot. I have find this out to be better sounding too.

 

[XV-1]

Sounds similar to removing the damping from Triplaner tonearm

 

[bazelio]

I did in the past and the sound is getting very dark .

+1. Not only that but low level detail was muted. This upper trough could theoretically be useful for carts that don't track well. But it didn't help my Master Signature (with custom compliance for the 4Point) which had tracking issues, so away it goes.

 

[jfrech]

Sounds similar to removing the damping from Triplaner tonearm

I agree, when I owned a TriPlanar I felt the damping trough removed was an improvement....

 

[bazelio]

An increased sampling rate? Too bad bazelio you have no context for your claim. Why do you hide your system?

Tim if you need further context for a reversible one-minute modification that you can easily evaluate for yourself, then I suggest you stop reading my forum posts.

 

[kodomo]

I tried and liked the results. It is much better than I was expecting. I can liken it to getting a very good alignment. Everything sounds a little better. Thanks for the heads up!

 

[Vienna]

I tried and liked the results. It is much better than I was expecting. I can liken it to getting a very good alignment. Everything sounds a little better. Thanks for the heads up!

I am glad you liked it! i guess that you have adjusted the VTF after the removal

 

[kodomo]

and here is a photo after removing them

 

[bazelio]

and here is a photo after removing them

Stabi M bros.

 

[twintech]

The sapphire pivot cup update for the Kuzma 4Point by Franc Kuzma a year or two back was, to me, an unequivocal improvement. I heard only upside after receiving my upgrade. Now, in a similar vein, @Vienna and I have discovered a modification that delivers another clear improvement to this already great arm. A modification so simple that it can be performed at home in under one minute. Savvas and I independently came to the same conclusion based on the same impressions of the before vs after: this is a no-brainer modifcation that makes the Kuzma 4Point sound like a new arm. A better arm. Savvas commented on increased dynamics. I agreed and also likened the change to an increased sampling rate. I hear no downsides.

The modification is simple: Remove the upper damping trough and paddle bracket. Though I wasn't using damping oil, I have always kept the trough attached. But, it adds mass and serves no purpose in the case where one isn't using it. After removing the trough, you'll find VTF needs to be reset, which means the moment of inertia about the pivot point has changed. Incidentally, I also recommend finding a counterweight configuration that allows for positioning the top weight as close to the pivot point as possible.

Hi bazelio, Thanks for the heads up! I did always wonder about doing this change, but for whatever reason, I never did it. I think maybe because it left that quite large hole in the side of the tonearm. But...as you say added mass that's not being used! So, I have now removed both vertical and horizontal troughs, and I have even removed the tiny allen scews!!! So I could get the top counterweight tracking force even closer to the pivot. I have also found a suitable rubber grommet to plug up that hole! Just have to say that, I am very pleased with this outcome indeed! From an already great sounding tonearm...is now sounding even more focused and detailed. Thanks!

 

[bazelio]

@twintech glad you're enjoying the "upgrade". I'm curious about the rubber grommet because I'd think it'll add damping. Did you do any critical listening with and without the grommet in place?

 

[twintech]

@bazelio Yes, I did do that today, and I couldn't tell the difference with or without But I take your point, about...( adding damping) so, you will be pleased to know that I have now removed it! Sound...comes before looks every time. Cheers.

 

[abeidrov]

Is it best to remove both vertical and horizontal troughs or just the vertical one?

 

[Hamburger]

I am have been using the first generation 4P arm with Stabi M, since day one.
I have removed both troughs long long ago, after trying damping fluid and empty troughs!

 

[bazelio]

I've only removed the vertical. And the sound improvement was clear as was the change to the arm's effective mass. Savvas may have also removed his lower trough, but I just leave it empty.