Current Production Phono Cartridge Capable for CD-4 Playback

[High Fidelity Mastering]

If you are looking for a new phono cartridge capable of playing CD-4 records, I have found the Ortofon Cadenza Black Moving Coil Phono cartridge an excellent cartridge. It will require a step-up transformer between your turntable and demodulator to bring its output up to a Moving Magnet level. I find its sonic characteristics and tracking ability are better than my JVC 4MD-20X and Audio Technica AT-20SLa cartridges. The Cadenza Black does have a Shibata stylus and its frequency range at -3db is 20-60kHz. Here is the brochure on the Cadenza series of Cartridges from the Ortofon website: https://www.ortofon.com/media/14808/mc-cadenza.pdf

 

[kfbkfb]

CD-4 requires careful setting of the stylus overhang and VTA, what sort of alignment systems/devices do you use for CD-4 overhang & VTA?


Kirk Bayne

 

[watsontr]

At Au$4k looks like I'm sticking with matrix

 

[High Fidelity Mastering]

CD-4 requires careful setting of the stylus overhang and VTA, what sort of alignment systems/devices do you use for CD-4 overhang & VTA?


Kirk Bayne

I use several measuring tools, here is a list of what I use and the links to where you can find them:

1. Ortofon Cartridge Alignment tool (Cartridge alignment tool)

2. SMARTstylus Alignment tool (acoustical systems - concentrating on the analog front-end - SMARTstylus)

3. I also use this alignment tool for cartridge and tonearm height settings: (https://www.amazon.com/Azimuth-Cart...ons+audio+alignment+tool,aps,108&sr=8-54&th=1)

4. Fozogmeter azimuth meter (http://www.musicalsurroundings.com/products/musical-surroundings-fozgometer-azimuth-meter)

5. Ultimate Analogue Test LP (https://store.acousticsounds.com/d/...ltimate_Analogue_Test_LP-System_Set_Up_Record)

6. Celestron 5MP digital microscope Pro (https://www.amazon.com/Celestron-Ha...1&sr=1-1-5985efba-8948-4f09-9122-d605505c9d1e)

7. Protractor and microphone stand with the digital microscope. for viewing on the computer.

The microscope with the stand it comes with is also good for examining stylus wear. I have attached a photo from the microscope on the mic stand with the Cadenza Black cartridge to give you an idea of the clarity of the measurement.

 

[kfbkfb]

Have you tried ultrasonic cleaning of records to be decoded/demodulated (some of the early [1972] CD-4 discs were made with vinyl without the added antistatic compound and have a tendency to attract dust into the record groove which disrupts retrieval of the CD-4 FM carriers)?

Ultrasonic record cleaners range from a few hundred dollars to a few thousand dollars.


Kirk Bayne

 

[proufo]

I have thought that if your tonearm allows for VTA adjustment in minute increments/decrements, you can use the CD-4 pilot light in a demodulator to adjust VTA. It would be a matter of adjusting VTA and one pot in the demodulator iteratively to find the position with the highest carrier signal level (which teoreticaly would be the position with the perfect alignment of the stylus contact line with the carrier modulations in the record).

You could --I guess-- for example adjust VTA in one direction until the demod "loses" the carrier and then do the same in the other direction, and set the VTA in the mid point. Increasing the resistance of the pot might allow for a very precise adjustment as it would reduce the VTA range. A few iterations might do the trick.

Fancier things could be done with an oscilloscope.

Before someone says it, using a CD-4 record of course.

Could someone with the right setup try and tell?

 

[kfbkfb]

In the case of the QSI-5022 CD-4 IC, there's a limiter prior to the FM demodulator, the limiter has a wide input range (IIRC 40dB) and outputs constant level carriers, so input carrier level changes would be lost in this process.


Kirk Bayne

 

[DuncanS]

In the case of the QSI-5022 CD-4 IC, there's a limiter prior to the FM demodulator, the limiter has a wide input range (IIRC 40dB) and outputs constant level carriers, so input carrier level changes would be lost in this process.


Kirk Bayne

Feed that into a pulse discriminator FM demodulator and you should have a good signal to pass to the next stage.

 

[J. PUPSTER]

I use several measuring tools, here is a list of what I use and the links to where you can find them:

1. Ortofon Cartridge Alignment tool (Cartridge alignment tool)

2. SMARTstylus Alignment tool (acoustical systems - concentrating on the analog front-end - SMARTstylus)

3. I also use this alignment tool for cartridge and tonearm height settings: (https://www.amazon.com/Azimuth-Cartridge-Elevation-Alignment-Headshell/dp/B07H4D4F5T/ref=sr_1_54?crid=2JN1NHEB6USCG&keywords=hudsons+audio+alignment+tool&qid=1679915956&sprefix=hudsons+audio+alignment+tool,aps,108&sr=8-54&th=1)

4. Fozogmeter azimuth meter (MUSICAL SURROUNDINGS Fozgometer V2 | Products | Musical Surroundings)

5. Ultimate Analogue Test LP (Analogue Productions-The Ultimate Analogue Test LP-System Set Up Record|Acoustic Sounds)

6. Celestron 5MP digital microscope Pro (https://www.amazon.com/Celestron-Handheld-Digital-Microscope-Pro/dp/B00CMJ1I08/ref=sxts_rp_s_a_1_0?content-id=amzn1.sym.eff26b9b-e255-411b-a40d-eccb21f93fe4:amzn1.sym.eff26b9b-e255-411b-a40d-eccb21f93fe4&crid=NOXRLVZIORJP&cv_ct_cx=celestron+5mp+digital+microscope+pro&keywords=celestron+5mp+digital+microscope+pro&pd_rd_i=B00CMJ1I08&pd_rd_r=e2a6fa0f-481e-4158-949b-fd8c85409924&pd_rd_w=ZwbKe&pd_rd_wg=VF37S&pf_rd_p=eff26b9b-e255-411b-a40d-eccb21f93fe4&pf_rd_r=ETABA3QFHB0389VJ0GEQ&qid=1679916451&sbo=RZvfv//HxDF+O5021pAnSA==&sprefix=celestron+5MP,aps,141&sr=1-1-5985efba-8948-4f09-9122-d605505c9d1e)

7. Protractor and microphone stand with the digital microscope. for viewing on the computer.

The microscope with the stand it comes with is also good for examining stylus wear. I have attached a photo from the microscope on the mic stand with the Cadenza Black cartridge to give you an idea of the clarity of the measurement.

The SMARTstylus looks interesting, was wondering where you got your SMARTstylus from?

I'm in the USA and found this seller that may have them:

Acoustical Systems SMARTstylus Alignment Tool I Shop Online

SMARTstylus is the 1st universal alignment Setup and balancing tool designed for an easy, fast and frustration free use for you.

www.avluxurygroup.com

 

[High Fidelity Mastering]

Have you tried ultrasonic cleaning of records to be decoded/demodulated (some of the early [1972] CD-4 discs were made with vinyl without the added antistatic compound and have a tendency to attract dust into the record groove which disrupts retrieval of the CD-4 FM carriers)?

Ultrasonic record cleaners range from a few hundred dollars to a few thousand dollars.


Kirk Bayne

What I found with ultrasonic cleaners is that unless you change the fluid after cleaning one record, the next record gets its bath in dirty water. I prefer using a manual fluid application with a follow-up vacuum, then adding LAST record preservative. Each record gets put in a new anti-static record sleeve and prior to playing I use a microfiber brush and the Furutech Antistatic gun on a spinning record to remove any static charge prior to playing.

 

[kfbkfb]

Going OT a little - a description of the QSI-5022 CD-4 IC (mentions the limiter portion of the FM system), .pdf page 40:

https://worldradiohistory.com/Archive-Radio-Electronics/70s/1974/Radio-Electronics-1974-06.pdf#page=38

Kirk Bayne

 

[Doug G.]

In a post, some years ago, Lou Dorren explained how, when the SH-400 was being designed, there was a disagreement between the Japanese engineers and him (he designed the QSI-5022 IC) because he told them a carrier level control was not necessary since the QSI-5022 has such a wide carrier level range capability. The engineers won out and carrier level controls were included.

However, the controls have very little effect on the demodulator being able to work and you can turn the control over it's entire range and, even though the meter will show the carrier level change, it makes very little difference in the operation.

Before I knew this, I wondered why, as a CD-4 record played and the carrier level was reduced as the stylus approached the center of the record, performance didn't degrade.

Doug

 

[J. PUPSTER]

I’m remembering this very informative article shared by Kirk a couple of years ago (a nice one for me to review as I may try some newer AT carts for CD-4):

Vertical Tracking Distortion

Stereo Lab Vertical Tracking Distortion Vertical Tracking Error

www.pspatialaudio.com

 

[par4ken]

When I repaired my Decca tonearm last year I had to epoxy the receptacle that the headshell plugs into. I notice now that the headshell sits with a bit of a forward cant. To level the cartridge I have to lower the base of the arm, not a problem except that it looks a bit odd and there is not a lot of clearance above the edge of the record. I could add a cartridge spacer to raise the height a bit enabling the base to be raised.
So I ordered an alignment tool, as suggested and linked to by, "High Fidelity Mastering".

https://www.quadraphonicquad.com/forums/members/high-fidelity-mastering.19847/

There are cheaper versions than the one linked to also available on amazon, they look to be about the same but for much less money.

The Decca headshell has a bubble level but mine is damaged and the similar Connoisseur headshells lack the level. So a gauge is a must.
Lately I've been getting really good CD-4 results with the AT-ART9XA cartridge, but results should be even better with the cartridge properly aligned.

Ultimate Analogue Test LP, also linked too looks very interesting. They have a large number of other test LP's available as well.