Billie Jean dance

[Thomas_A]

the record is so bumby anything can happen

Do you have the Thriller album? Would be interesting to see whether the SME5 behaves identically on Billie Jean. It might have more lateral mass.

 

[Thomas_A]

Yes, in addition to the slight off center pressing you can easily see the tonearm bopping to the beat, especially that first hit in Billie Jean. I'll have to see if my Moerch UP-4 / Grado Sonata does the same.

Martin

Did you check?

 

[Balle Clorin]

Do you have the Thriller album? Would be interesting to see whether the SME5 behaves identically on Billie Jean. It might have more lateral mass.

No, sorry no Michael Jackson music in my home. But I have a Bump in my CA TRS1007 that is easy recognisable, but that may not be relevant here. Here is my SME V in action.. The bumps are frequency markers in the track 1t 15 -50-160

 

[JP]

This is the beginning of Billie Jean. It seems that a LF around 8 Hz, in phase (lateral) comes after the large beat. It is in the region of resonance (11 Hz) and also higher in level compared to the song before. It does not seem to bleed from the music signal, and it is still possible that this is cut into the record. There is no way to know unless there is another forum member that could test the same using an arm with high mass in the lateral direction.

View attachment 377882

And spectrum:
View attachment 377883

Spectrum for the song before:

View attachment 377884

When this was first posted on AK I was going to get the record and investigate, but then… squirrel!

 

[JP]

I also learned somewhere (I think it might have even been here at ASR, amazingly enough!) that Audacity can be used to get a fairly good estimate of the system resonance for one's record playing gizmo by 'recording' while playing an unmodulated groove.

Doesn’t need to be unmodulated - record anything and it’ll generally stand out.

 

[Thomas_A]

When this was first posted on AK I was going to get the record and investigate, but then… squirrel!

Squirrel?

 

[Thomas_A]

No, sorry no Michael Jackson music in my home. But I have a Bump in my CA TRS1007 that is easy recognisable, but that may not be relevant here. Here is my SME V in action.. The bumps are frequency markers in the track 1t 15 -50-160
View attachment 378029

No it is not really comparable to what Is seen in Billie Jean.

 

[JP]

Squirrel?

Distraction. Reference to a character in the movie Up.

 

[Thomas_A]

Distraction. Reference to a character in the movie Up.

Ok then I get it. I know that movie.

With respect to the track and the visible lateral movement of the arm at the music beats it must mean that the 8 Hz component seen after the beats mainly, or completely, is derived from the arm movement.

Damn it. This just make me wanting that Moerch DP-8 even more.

Would you happen to have a tonearm with high lateral mass?

 

[JP]

I’ve all the EPA-500 wands - not sure if one of those would do.

 

[sergeauckland]

Ok then I get it. I know that movie.

With respect to the track and the visible lateral movement of the arm at the music beats it must mean that the 8 Hz component seen after the beats mainly, or completely, is derived from the arm movement.

Damn it. This just make me wanting that Moerch DP-8 even more.

Would you happen to have a tonearm with high lateral mass?

You need an arm with similar horizontal and vertical moving mass, as the cartridge should have identical vertical and horizontal compliance.

S

 

[Thomas_A]

You need an arm with similar horizontal and vertical moving mass, as the cartridge should have identical vertical and horizontal compliance.

S

Why?

 

[sergeauckland]

Why?

Because the arm/cartridge resonance needs to be at around 11Hz. This keeps the resonant frequency above the warp frequencies and well below the audio frequencies. If the compliance is the same in both planes, as pretty much all cartridges have, then arms with different masses in the vertical and horizontal planes will result in different resonant frequencies. If you get one right, the other will be wrong.

There are some arms, like some of the air-bearing linear tracking arms, that have a small mass vertically (just a short arm tube) and a large mass horizontally, (the air bearing).

There are pivoted arms that have similar oddities. A conventionally pivoted arm with gimbal, unipivot or knife-edge/ball bearings like the SME, will have substantially similar moving masses in each plane.

S.

 

[Thomas_A]

Because the arm/cartridge resonance needs to be at around 11Hz. This keeps the resonant frequency above the warp frequencies and well below the audio frequencies. If the compliance is the same in both planes, as pretty much all cartridges have, then arms with different masses in the vertical and horizontal planes will result in different resonant frequencies. If you get one right, the other will be wrong.

There are some arms, like some of the air-bearing linear tracking arms, that have a small mass vertically (just a short arm tube) and a large mass horizontally, (the air bearing).

There are pivoted arms that have similar oddities. A conventionally pivoted arm with gimbal, unipivot or knife-edge/ball bearings like the SME, will have substantially similar moving masses in each plane.

S.

Yes, it might be so. But LPs, at least 99% of them, do not have any music content cut in the vertical direction below 100 Hz. Bass is lateral (mono). The record contains "noise" in forms of 0,55 Hz lateral record eccentricity, ad the average 4-6 Hz vertical warp frequencies. Thus there is no reason to have lateral and vertical resonance frequency the same; in fact it should be an advantage to have them different. That is the idea of the DP-8 tonearm.

 

[JP]

@Thomas_A, do any of the digital versions have similar LF content?

 

[Thomas_A]

@Thomas_A, do any of the digital versions have similar LF content?

I could check later. I know at least two having the DP-8 and I have sent out a question.

 

[Balle Clorin]

Because the arm/cartridge resonance needs to be at around 11Hz. This keeps the resonant frequency above the warp frequencies and well below the audio frequencies. If the compliance is the same in both planes, as pretty much all cartridges have, then arms with different masses in the vertical and horizontal planes will result in different resonant frequencies. If you get one right, the other will be wrong.

There are some arms, like some of the air-bearing linear tracking arms, that have a small mass vertically (just a short arm tube) and a large mass horizontally, (the air bearing).

There are pivoted arms that have similar oddities. A conventionally pivoted arm with gimbal, unipivot or knife-edge/ball bearings like the SME, will have substantially similar moving masses in each plane.

S.

That ( SME) means that my AT OC9MLii has very different compliance vertical and lateral . ..

 

[Thomas_A]

That ( SME) means that my AT OC9MLii has very different compliance vertical and lateral . ..

This is the arm having different mass laterally and verically. Similar but not as much with my older Linn Akito.

 

[mhardy6647]

Historically (at least), vertical and horizontal compliance of many cartridges differ(ed). I don't know about the cartridge in the OP.
I do assume y'all know that the stereo (two channel) information is encoded in a "multiplexed" way in the record grooves, yes?

How to pack a stereo signal in one record groove

phono, analog, vinyl, recorder, single, maxi, disc, dubplates, cut, dubrecord, record, directmastering, pressing, pressung, schallplatten, herstellung, einzelplatten, master, lathe, audiodiscs

www.vinylrecorder.com

(the "mono = lateral" comment posted earlier indicates that at least that poster does -- but I don't want to assume about everyone else)

 

[Balle Clorin]

This is the arm having different mass laterally and verically. Similar but not as much with my older Linn Akito.

I am not an expert, but as long as the mass distribution along the rod representing the tone arm is the same , relative to the rotational axis , the inertia will be the same. Turning the figure 90 degrees will represent vertical rotation but the inertia= effective mass will be the same. Since the main inertia is from the cartridge end the the effective mass cannot be very much different between vertical and horizontal rotation.