Fun with vinyl measurements

[dougi]

Same magnetic sensor head and control board I guess, for details you have to look at the service manual.!
51F has a beefier motor than 47,37,21,23, but not as big as 59/62 and your 50M I guess.

Replace your caps before you get in trouble…

I just recapped it today, with whatever tier 1 caps were available from the wholesaler (RS Components). Not too tricky and it is working better. It used to creep after stopping, but no more!

 

[Balle Clorin]

Pink noise calibration above and her is and RIAA calibration files

Plot you cartridge response in REW, using a test record

Easier to use Trace Arithmetic in REW.

1. Make a test record recording with RIAA into REW/PC. Prerequisite -Make a calibration file for your souncard for most accurate results.
The record is assumed to be with Clearaudio CA-TRS-1007 EQ= RIAA below 1 khz, no RIAA above. Ortofon test record can be used to but result is only valid above 2000hz
2. Import sweep file i REW, Import attached correction file. File /Import/Import Audio Data
3. Go to ALL SPL tab and open Trace arithmetic from the Actions button, click Generate
4. BANG your cartridge (+RIAA )response is plotted in blue here

For making different compensation files use the attaches Excel file "RIAA Curves-Copy.txt" and rename to .xlsx
The current setting makes the green curve that removes the recorded RIAA effect above 1000 Hz for theTRS-1007 type record, and also makes it flat by including a 10db/decade compensation(inverse pink noise or log sweep response)

EDIT:AUG 31 PLOADED CORRECTED RIAA EXCEL FILE

 

[Balle Clorin]

if you do not disable the 20 db limit you may not be able to use the full range of a calibration file.. when using calibrating function. Not å limit with Trace arithemetic

 

[JP]

The current setting makes the green curve that removes the recorded RIAA effect above 1000 Hz

Truly?

 

[Balle Clorin]

Note this is concerning recording through a RIAA.
What I was trying to say was initially for a guy recording a ortofon record ( -1007 or similar above 1000hz) through a RIAA, the compensation file inverts the RIAA 1khz+effect back to a flat response.

Running A TRS-1007 record through a RIAA makes the 20-1khz range flat,- the TRS-1007 has the bass Eq from RIAA and will be correct there- but since the range above 1000hz where the record has no Eq the result after RIAA recording will be wrong without a correction, it will slope down, the correction file inverts that slope - making the response flat 20-20 000

Most people do not have a flat Eq amplifier for vinyl , but are forced to use a RIAA


This record:

with this RIAA for recording,

gives this end result when recorded, kind of hard to judge cartridge response from this... the I found the setting the limited the correction db in post 2003, inticking that makes it possible to use the correction file vie the Calibration choice in REW

The correction files modifies the recorded track so it becomes flat

What is not shown here is the correction part that makes a sweep look flat ( 10db/decade)

At first I had difficulty making the total correction work as a calibration file in REW.. so I used Trace arithmetic as a work around
o
But with the 20 db limit un-ticked as in post 2003 it works fine as a calibration file too

Do not know why the first correction file got corrupted, here is a working one again, for use as calibration input file

 

[JP]

Running A TRS-1007 record through a RIAA makes the 20-1khz range flat,- the TRS-1007 has the bass Eq from RIAA and will be correct there- but since the range above 1000hz where the record has no Eq

This is the part that may be ambiguous as the bass EQ and shelf has an effect to around 2.5kHz. Probably splitting hairs, but this stuff can be challenging to understand, so precise explanations can help people.

 

[Balle Clorin]

I am lazy and too tired today, sorry

 

[Palmer]

Korf is back to blogging - interesting article about cartridge alignment - might have to buy that test record, too - 1kHz on both sides, throughout, 33 on one side and 45 on the other side.

The Trap of Mental Experiments

korfaudio.com

Testschallplatte TLP-1

Normal 0 21 false false false DE X-NONE X-NONE…

sperling-audio.de

Edit: Example measurement

 

[Bob from Florida]

Korf is back to blogging - interesting article about cartridge alignment - might have to buy that test record, too - 1kHz on both sides, throughout, 33 on one side and 45 on the other side.

The Trap of Mental Experiments

korfaudio.com

Testschallplatte TLP-1

Normal 0 21 false false false DE X-NONE X-NONE…

sperling-audio.de

Edit: Example measurement

View attachment 473828

Real world and theoretical don't always intersect in the predicted manner. Interesting read that needs some independent verification.

 

[Palmer]

Real world and theoretical don't always intersect in the predicted manner. Interesting read that needs some independent verification.

I agree - I thought it is interesting enough to post it here, the record is certainly something I will order. It gives one time, vs the short tracks on other test records...
Haven't seen someone do the tests like this before.

 

[Thomas_A]

Distortion is calculated at 10 cm/s. Test record is -10 dBu. Whatever that means.

 

[Palmer]

Distortion is calculated at 10 cm/s. Test record is -10 dBu. Whatever that means.

I think, correct me if I am wrong - Mr. Korf took the test and data from the VLADAN M. JOVANOVIC article he quotes, and replicated it with the Sperling disk's 1kHz across the whole record surface - to see what figures he gets, compared to what the Loefgren A and C would state in THD to be expected. The man makes a good Tonearm, and I follow his blog, always an interesting view from Korf Audio.

E-library page - AES

AES E-Library ← Back to search

aes2.org

 

[Thomas_A]

I think, correct me if I am wrong - Mr. Korf took the test and data from the VLADAN M. JOVANOVIC article he quotes, and replicated it with the Sperling disk's 1kHz across the whole record surface - to see what figures he gets, compared to what the Loefgren A and C would state in THD to be expected. The man makes a good Tonearm, and I follow his blog, always an interesting view from Korf Audio.

E-library page - AES

AES E-Library ← Back to search

aes2.org

What is needed is 5 or 10 cm/s velocities. But other distortions swamp the LTA error anyway

 

[Balle Clorin]

I did the same experiment using another record with varying results... Tried to buy the record Korf used, but I could nor purchase outside Germany

And then a sum to null check on an old CBS record minimum at 110mm radius

 

[Balle Clorin]

I agree - I thought it is interesting enough to post it here, the record is certainly something I will order. It gives one time, vs the short tracks on other test records...
Haven't seen someone do the tests like this before.

I could not choose my country for shipping, only Germany as option it seems, please me know if you find out how yo get shipment outside Germany

 

[Palmer]

I had the same problem with UNITRA, I eventually got one - haven't had time to use it, Life... @ThomasA is waiting for me on that one... I'll find out and post it, if there's a way.

Danish Sound parts, Bang und Olufsen parts supplier - stopped shipping to US and Puerto Rico for the time being, completely. Gonna be a rough stretch for a while.

Turntable Test Vinyl Record - Laboratory Edition | Unitra

Created in collaboration with our partners at Takt, this recording brings together the company’s broad expertise and extensive experience in the field of analog audio.

unitra.com

 

[Balle Clorin]

This is the part that may be ambiguous as the bass EQ and shelf has an effect to around 2.5kHz. Probably splitting hairs, but this stuff can be challenging to understand, so precise explanations can help people.

I made calibration files so people without the script can use their RIAA and REW, with a CA-TRS-1007 type record, and added a Ortofon to CA-TRA-1007 correction too..so an Ortofon record may be used to estimate the response

Errors in soundcards and RIAA will end up in the plot if not corrected for...

Ortofon X40 from SHF look like this

and the script like this

 

[Thomas_A]

Regarding LTA distortion, Yosh is the reference (as he mostly is). Korf needs to study the subject a bit more...

Note on Record Specifications

"BTW: There is no effective measuring method for distortion due to lateral tracking angle error because this kind of distortion is usually masked by much bigger distortions (i.e. tracing distortions) when tracing actual record with a stylus tip of considerable contact radii. Also read as follows about the comparison of various distortions. Generally tracking (angle) error distortion is in small order (less than 2%) in comparison with tracing error distortion (often exceeding 10%) due to effective contact radius of stylus tip. Hence in order to check angle error and alignment it is of no use to see playback wave forms on oscilloscope since distortion rate ascertainable on oscilloscope should be more than 10% otherwise not easy to find as a distortion or deformed wave. Actual impulsive mis-track (stylus skipping from groove walls mainly due to defective groove or dirty sticky stylus) can be seen on oscilloscope or heard very cruelly with our ears."

 

[Balle Clorin]

Still Korf shows how superior advanced styli are, and why no serious audiophile should use a conical stylus..

Josh reasonings and sources are probably based on conical and ellipticals ?

 

[Palmer]

Regarding LTA distortion, Yosh is the reference (as he mostly is). Korf needs to study the subject a bit more...

Note on Record Specifications

View attachment 473891

Well, tough crowd, I suppose... With all due respect - this graph looks like math, not actual measurement? I'll read the paper when I have extra time, but for now color me skeptical.