Fun with vinyl measurements

[JP]

 

[Balle Clorin]

Turntable feedback/microphony:

Stylis resting in record groove on TT while room silent, vs pink noise played in room, cannot recall sound level

 

[Balle Clorin]

Test records for more fun arrived today HFS75 and BBC stereo test disc. a third one in transit

 

[Balle Clorin]

It is kind of obvious but people may not know this method.
I just made a calculation to determine the effective mass of arm+Pickup, no need to know cartridge compliance, but it can be calculated from the result.
Input is F1 resonance frequency from test disk, F2 is resonance with X gram weight added to arm/headshell tip

Spoiler: Derivation

 

[JP]

I couldn't help it. Now to find a charter recorder for cheap that hopefully doesn't need too much work to get running again.

 

[Watire]

I couldn't help it. Now to find a charter recorder for cheap that hopefully doesn't need too much work to get running again.

View attachment 439583

Could you explain how one use it ? Do you need a scope ?

 

[JP]

https://www.technicalaudio.com/pdf/Bruel&Kjaer/Bruel&Kjaer_Response_Test_Unit_w_Test_Records_4416_QR-2009_QR-2010_QR-2011.pdf

 

[Balle Clorin]

Looks brand new!!! Never seen that for sale before, I have the records and manual , Please post sweeps comparing with the script EQ.

 

[Balle Clorin]

 

[JP]

Looks brand new!!! Never seen that for sale before, I have the records and manual , Please post sweeps comparing with the script EQ.

I saw one on eBay maybe about a year ago, but the asking price was well over USD $1000. This one popped up for $290, is in great physical shape, and looks to be untouched internally. Curiosity got the better of me.

 

[Balle Clorin]

View attachment 439764

An adjustment to get the proper change to effective mass , due to the counterweight effect-which I ignored above- , the actual weight added should be less.. 70-80%

 

[Balle Clorin]

Finally a test record with a track to really check channel phase difference, useful for alignment, since it is at 120-121mm nullpoint where correct zenith should give zero phase diffrence. Toshiba LF-90001 R

Right channel arrived 4 us before left.. hmme how many degrees Zenith error wlll that be at 45rpm , I had a notepaper with that on but my wife tidied and it is gone...

Well AI Microsoft Copilot calculated for me that the Zenith error was 0.062 Degrees, while the correct answer is 5.17 degrees. It told me to turn the stylus in the WRONG direction to correct for the the Zenith error, and it told med that the L-R channel phase difference at 1000Hz was more than 9000 degrees when the correct answer is 1.44 degrees

So this AI cannot be trusted when it comes to vinyl calculations...

Spoiler: AI

maybe AI could help? Is that 0.062 degrees really correct?

Forced AI to use groove width ( AI used 70um)

But I do not agree...

It took maybe longer do debate this with AI than doing the math myself oncemore, I am still not sure the 5 degrees is correct.... well my hand calc in excel agrees

But is it really true that my AT OC9MLii is off by 5 degrees as the record indicates?

 

[somebodyelse]

So this AI cannot be trusted when it comes to vinyl calculations...

So far AI has a terrible track record on calculations of any sort, and on anything where factual accuracy is important.

 

[stormobile]

Hi all, I am new to vinyl measurements but now that I have WiiM ultra as a phono stage I am thinking of using it for cartridge setup (by recording with Hifime UR23 Tousling to PC USB). I've got some novice questions for those with experience:
1) What is the best New Test Record to buy in the US? I know that most of them are not good and there are tradeoffs but what would be the easiest reasonable one to purchase new?
2) Do we have a script for cartridge setup using those records. Like it is quite obvious on how one should check the azimuth but can we also check overhang or VTA with test records digitalizing ?

 

[Balle Clorin]

1.Test record for channel balance Azimuth + tracking. Ortofon Test Record for crosstalk/azimuth and tracking . The other Tracks on the record are useless. Analog Production test record have Even better crosstalk/Azimuth track.
CBS STR-100 is the cheapest frequency sweep that is useable. ClearAudio CA TRS-1007 is the best new available.
analyse files and filter them in PC for crosstalk distortion etc. REW is free and useful. Audacity is free but Kind of useless. I use cooleditpro2=Adobe audition . Isotope Rx is used by others. Really cheap but excellent old test record for balance and crosstalk at 400hz is Toshiba LF-90001 on side B. https://www.discogs.com/release/7924705-Various-Professional-Series-Vol1-Hearing-Test-Record

2 script

Phono Cartridge Response Measurement Script

This thread is intended to consolidate the technical discussion and further development of Scott Wurcer's frequency response measurement script to a central area. I'd like to keep this discussion about the tool rather than specific cartridges. I'll edit this and the subsequent reserved posts in...

www.audiosciencereview.com

User also made a very good guideline

Overhang and zenith is not covered bye any script. VTA can be seen indirectly by judging overall evenness in frequency response and channel similarity. In theory zenith alignment and overhang effects should be visible buy noting change in distortion across a whole record side, But I have had poor success with it using Clearaudio Treckability test record with 15 minutes 3150 track, only a shade of one null point and never seen 2.

 

[stormobile]

ClearAudio CA TRS-1007

Judging by the track list it would be applicable to testing azimuth too with 1khz mono test records, right?

 

[Balle Clorin]

You could maybe use the 1khz pilot tone before the channel sweep yes. Cannot recall if pilot tone is in main test channel or both… But anyway I trust the Toshiba/Ortofon/Ultimate more

To test Azimuth /crosstalk you need a signal in Only one channel…mono is same signal in both, and cannot give real crosstalk values.

 

[stormobile]

You could maybe use the 1khz pilot tone before the channel sweep yes. Cannot recall if pilot tone is in main test channel or both… But anyway I trust the Toshiba/Ortofon/Ultimate more

I read https://www.discogs.com/release/248...EEA8FgGxGUAO8q2dO2i3HzahM1fmzNPTLwzGpGu8NiOGi tracks 5-6 description as one channel only. Am I wrong to assume it?