Korf latest blog - tests 4 arm types for THD including U/Hang with surprising results

[tabarddn51]

Hi, Korf has released his latest experiment into arm/cart performance looking at THD for 4 different arm types.
The Answer to THD Puzzle is... More Puzzles

Cheers

 

[Thomas_AA]

Hi, Korf has released his latest experiment into arm/cart performance looking at THD for 4 different arm types.
The Answer to THD Puzzle is... More Puzzles

Cheers

He has not understood that the calculated tracking error curve is at much higher level than the Sperling record is recorded at, and that other distortion components swamps the tracking error. Has he any clue of the zenith and inter channel phase error?:

Post in thread 'Math to show WHY under-hang tonearms sound superiors'

Apr 11, 2026

Well, it looks to me more like Yamaha is saying the additional angular error is not as bad as it looks, more than they're suggesting an underhang is superior. In addition to their conclusions, Korf has measured actual playback distortions and found little correlation with theoretical numbers, suggesting that the degree of angular error is swamped out by other factors. For me, it just makes sense that the anchor point resisting friction should be directly behind the stylus-suspension line rather than off to one side.

Korfs error is that he compares the theoretical 10 cm/s signal...

• Thomas_AA

 

[borchee]

I don't see any value in this "test", besides the sales pitch.

Neither they use the same drive/turntable with all four arms, nor do they use one and the same cartridge...and they compare their new arms, mounted to whatever drive (new, I guess) to a 45 years old turntable.

There are linear tracking arms in current production, if one would want to compare technical principles:
- AV Design Haus
- Bergman Audio
- Clearaudio
- Kuzma
- ...

 

[tabarddn51]

Hi, I have read the Korf blog again to make sure I was reading it correctly, from my take.
- He has used the same cart for all tests a ATN112EP (presumably Elliptical)
- Do you mean he using a 45 year old T/T with a linear tracker arm, The T/T will not make any difference to the test results. If the Linier Tracker is that old, provided it is well maintained, that also should not make a difference to the results. I use a refurbished 50 year old T/T as my main deck.
- I would not think he is using the results as promotional material, because his arms results 9with the exception of the U/Hang arm) are so were near state of art. I am amazed that the U/Hang are is so consistent across the range, especially with what has been posted previously on the down sides of this type of arm.

- Perhaps he will now come out with his own official U/Hang version, if he does I wish him the best of luck.

Cheers

 

[EWarrior]

He has not understood that the calculated tracking error curve is at much higher level than the Sperling record is recorded at, and that other distortion components swamps the tracking error. Has he any clue of the zenith and inter channel phase error?:

Post in thread 'Math to show WHY under-hang tonearms sound superiors'

Apr 11, 2026

Well, it looks to me more like Yamaha is saying the additional angular error is not as bad as it looks, more than they're suggesting an underhang is superior. In addition to their conclusions, Korf has measured actual playback distortions and found little correlation with theoretical numbers, suggesting that the degree of angular error is swamped out by other factors. For me, it just makes sense that the anchor point resisting friction should be directly behind the stylus-suspension line rather than off to one side.

Korfs error is that he compares the theoretical 10 cm/s signal...

• Thomas_AA

right, considering the velocity and RIAA preamp, the distortion is would be about a third of his estimate – and that is with some alignment error considered. A perfect alignment would have even lower tracking distortion.

 

[Thomas_AA]

right, considering the velocity and RIAA preamp, the distortion is would be about a third of his estimate – and that is with some alignment error considered. A perfect alignment would have even lower tracking distortion.

The H2 distortion I get is between ≈0.3% at outer to around ≈1% at inner, with a SAS MR stylus and the Sperling record.

 

[EWarrior]

Quite a lot of distortion, but the Korf measurements show the same problem:
I calculated this for Baerwald null points, 3µm stylus curvature, 215mm PTS, 2.5cm/s peak velocity, 33.3rpm with RIAA compensation

 

[Thomas_AA]

Quite a lot of distortion, but the Korf measurements show the same problem:
I calculated this for Baerwald null points, 3µm stylus curvature, 215mm PTS, 2.5cm/s peak velocity, 33.3rpm with RIAA compensation

To that there is crosstalk. Crosstalk is at best ≈-35 dB and phase/zenith between L/R matters.

 

[tabarddn51]

Hi, From another site, they recon the Linier tacker is a Technics SL7 linear tracker, as he has used this deck on other tracks.

Cheers

 

[borchee]

They stated that themselves in the initial post/test.



So...not the same turntable and cartridge were used.

 

[Beobloke]

What worries me is his comment that "Curiously, practically every single person got the answer wrong! Here's the correct legend: Red is a linear tracker. Blue is TA-SF9R."

Er, so people couldn't work out instantly that the trace with lower distortion came from the linear tracker?!

Oh dear...

 

[tabarddn51]

Hi, What's even more surprising is that people have not worked out or commented the the 10'' Under hang arm give the most consistent (level variable) result of the 4. (Black Line). Even thought it was not set up to an optimum position & he cannot understand why.

Cheers

 

[Thomas_AA]

Hi, What's even more surprising is that people have not worked out or commented the the 10'' Under hang arm give the most consistent (level variable) result of the 4. (Black Line). Even thought it was not set up to an optimum position & he cannot understand why.

Cheers

It has the highest distortion of them all, which is not strange.

 

[Thomas_AA]

Quite a lot of distortion, but the Korf measurements show the same problem:
I calculated this for Baerwald null points, 3µm stylus curvature, 215mm PTS, 2.5cm/s peak velocity, 33.3rpm with RIAA compensation

A small movie of how it looks.

Dropbox

www.dropbox.com

 

[Mr Boochie]

Do they explain the large tracking THD of their TA-SF11R (11") arm at 132mm (green line)? That really stood out on the graph. It looks like inner tracking distortion to me.

 

[Thomas_AA]

Stylus probably. Tracing error.

 

[Mr Boochie]

Stylus probably. Tracing error.

It's pretty significant. The other two graphs don't display that level of tracing (tracking?) error throughout the record.

 

[ripblade]

Do they explain the large tracking THD of their TA-SF11R (11") arm at 132mm (green line)? That really stood out on the graph. It looks like inner tracking distortion to me.

I noticed that as well. Also, the underhung arm has the lowest distortion of them all at the inner groove, whereas the LT has the highest. I wonder what accounts for these anomalies?

 

[ripblade]

Hi, What's even more surprising is that people have not worked out or commented the the 10'' Under hang arm give the most consistent (level variable) result of the 4. (Black Line). Even thought it was not set up to an optimum position & he cannot understand why.

Cheers

The fact that the distortion all across is no higher than any arm at the inner groove may be why it's considered benign by the advocates....the LP has consistent distortion across its entirety rather than just at the end, perhaps making it less noticeable.

 

[Mr Boochie]

The fact that the distortion all across is no higher than any arm at the inner groove may be why it's considered benign by the advocates....the LP has consistent distortion across its entirety rather than just at the end, perhaps making it less noticeable.

Don't those advocates listen to the last song of each side?