Technics SH-400 and the CCC

[kfbkfb]

I got an SH-400 in late 1992, my turntable has low capacitance cables and my Shure V15 Type 3 cartridge has a MicroRidge stylus.

I never owned/used a CD-4 adjustment record.

Going by the statement in the 1972-12 issue of Stereo Review that the CD-4 performance of the Shure V15 Type 2 Improved cartridge w/Eliptical stylus was as good as a CD-4 cartridge, I thought my Type 3 would work and it did.

I don't know the specifics of the CCC system, but I didn't notice that it helped my non-CD-4 cartridge.

Anyone with the special Technics CCC test record and a (CD-4/non-CD-4) cartridge that was audibly helped by the CCC system (the audible result would be lower distortion in the difference signal due to less interference/higher channel separation between the Left and Right FM carriers)?


Kirk Bayne

 

[Doug G.]

I have have never had the special Technics record and I originally set the CCC controls to mid range with satisfactory results and, in fact, it didn't seem to make much difference in performance where I set them.

However, more recently, I was involved in a conversation (I believe it was on here) and another user said he just used a regular CD-4 record, not a test record, and set the CCC controls for minimum output as indicated on the meters and so that is what I have been doing since then.

It's probably not entirely correct but it doesn't seem to hurt, either. The CCC circuit must be looking at the opposite channel carrier and then looking to see how much of that signal is appearing in the channel in which you are interested. You then adjust for minimum output and thus, minimum crosstalk between channels.

I have always used cartridges designed for CD-4. I believe it's a compromise using others because, even though non-CD-4 cartridges may work in most cases, they will almost always fail in very difficult situations, complex and high decibel string/horn/orchestral passages, for example.

I have several 2 channel cartridges I have tried and found that to be true. They are so close to being almost perfect but fail where genuine CD-4 cartridges work. Even the Audio Technica AT440MLx cartridges aren't as good as, say, the Empire 4000D series or the Pickering XUV 4500Q or the Panasonic SG cartridges.

Doug

 

[surround.sound.enthusiast]

I don't own an SH-400 yet, but was eyeing one recently (without the calibration disc, of course). Because of that I was reading the manual about it. It backs up what you mentioned Doug G. about adjusting the CCC knobs until the meter moves as far to the left as it will go. It just might take a variety of discs or passages to make you've gotten it as close as you can without the calibration disc. Here's an image of the back of the English version of the disc too.

 

[kfbkfb]

At some point (IIRC, ~20dB channel separation above ~15kHz), increasing the channel separation doesn't improve the fidelity of the CD-4 difference signal (the difference signal is also subject to distortion due to harmonic distortion from the baseband/sum signal, intermodulation distortion between the baseband and carrier and tracking errors of the carrier signal that causes the wrong instantaneous [FM] frequency to be sent to the demodulator).


Kirk Bayne

 

[Kbunting]

I don't own an SH-400 yet, but was eyeing one recently (without the calibration disc, of course). Because of that I was reading the manual about it. It backs up what you mentioned Doug G. about adjusting the CCC knobs until the meter moves as far to the left as it will go. It just might take a variety of discs or passages to make you've gotten it as close as you can without the calibration disc. Here's an image of the back of the English version of the disc too.

View attachment 65118

I bought an intro to quad the jvc made that has left front bell left rear is this the calibration disc?

 

[Doug G.]

I bought an intro to quad the jvc made that has left front bell left rear is this the calibration disc?

A calibration disc will have tones to adjust the separation, carrier level and then, various channel identification tracks. Some have a human announcing the tracks, some have bells, some have music.

If you are asking whether or not the one you have is the subject disc, no, it isn't. The only calibration disc with the CCC adjustment tracks is the one that came with the SH-400, the SPR-123.

Doug

 

[kfbkfb]

https://www.quadraphonicquad.com/fo...-4-demodulator-archive.9035/page-4#post-71594
CCC isn't needed: "The capture ratio of the QSI5022 is probably why some non CD-4 cartridges give some CD-4 performance."


AFAIK, the SH-400 was the only demod w/CCC.


Kirk Bayne

 

[Doug G.]

The CCC adjustment is to optimize the crosstalk setting between the two carriers but it isn't real critical. I just use any CD-4 record, activate both CCC controls in turn, adjust each channel for minimum signal on that channel and leave it at that. I don't routinely do it. It probably isn't entirely correct but seems to work.

It seems I saw a Technics receiver or amp. with the CCC adjustment on it but I'm not at all sure.

Doug