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I notice that CDjapan have listed a load of Universal (DG) titles which they claim utilise 'Rubidium Clock Cutting'. I have read a bit about this from JVC who claim it uses high res masters to give RBCD at a much higher quality (though nowhere do they claim to be as good as SACD). I apologise if this is old news but this process is new to me. Can it be used to further enhance SACD? The Universal titles are being offered at very good prices. Are they a challenge to SACD in quality? I know they are not MCH and at the end of the day they are still RBCD. The selection listed includes quite a lot of vintage material which would have been very desirable on SACD.
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Post by Naun February 23, 2012 (2 of 18)
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old-dog-newtricks said:
The selection listed includes quite a lot of vintage material which would have been very desirable on SACD.
I had the same, perhaps somewhat selfish, thought. Titles like the Schneiderhan Beethoven concerto or the Fournier Bach suites would be irresistible in SACD transfers of comparable quality to some of the recent Japanese Universals.
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old-dog-newtricks said:
at the end of the day they are still RBCD
You've answered your own question!
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I have a sizeable collection of RCA Living Stereo / Red Seal reissues by BMG Japan on RBCD. This series features rubidium clocking and JVC's K2 process but is priced like regular CDs (which is to say about 2000 yen; CDs are generally more expensive in Japan than in other markets). The sound quality is uniformly excellent. Compared to the US Living Stereo SACDs, they are less warm (eg more neutral) and have a narrower sound stage but have a very quiet background, crystaline trasients, and gentle bloom. How much of that is due to the clocking rather than just a superb mastering job I cannot say.
Esoteric's SACD reissues also use rubidium clocking as do many XRCDs I believe.
I heard a demo by Esoteric with their rubidium clock switched on and off in an SACD playback chain consisted of their top of the line D/A and transport products. The effect of the clocking was noticeable and made the music more effortless, organic and coherent. In other words less digital artifacts. This was especially apparent when the clock was suddenly switched off.
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In remastering the US RCA Living Stereo SACD reissues, SoundMirror used a dCS A/D chain consisted of a dCS 992 word clock. (This is in the liner notes.) The same clock is also used at the JVC Mastering Center in Yokohama where the XRCDs and Esoteric SACD reissues are remastered.
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Post by Lindberg February 24, 2012 (6 of 18)
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There's no clock involved in either CD or SACD manufacturing. In a pure production path the only clock affecting the sound is the one feeding the AD converter at the original recording sessions.
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Post by Zammo February 24, 2012 (7 of 18)
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alan_dorkin said:
The whole SHM-SACD marketing and pricing is based on customer ignorance.
Don't disagree that the prices are high, but what do you think they sound like Alan?
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Post by pacwin February 24, 2012 (8 of 18)
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alan_dorkin said:
If I understand correctly they use extra DA/AD conversion in SHM-SACD mastering (for some idiotic marketing reasons). This means that there are three possible sources for jitter instead of just one: original AD conversion, DA conversion and then AD conversion to DSD. Advertising "rubidium clocks" for the last two conversions conveniently forgets the clock in the original ADC, which could be any old granny watch for all they care. The whole SHM-SACD marketing and pricing is based on customer ignorance.
I didn't think the rubidium clock has anything to do with what you are suggesting: as I understand it is to increase the precision and accuracy of the pits and lands cutting on the glass masters. The rubidium clock presumably guides the laser switching when setting the photoresist on the glass master. SHM-CD/SHM-SACD do seem to improve the sonics when you have to use a spinning laser disc reader, but this evaporates when you move the files to a computer server.
In other words there is nothing necessarily special about the files on these discs, the objective is to improve the quality of the data read by the player (the clocking, grade of polycarbonate and green non reflective coating). I've been able to compare the files on the Diana Krall "The Girl in the other Room" SACD vs the same SACD-SHM and once you have them as files on a computer they are bit identical, although there are small sonic gains with the SHM-SACD on a laser turntable. The small gains from SHM would in my view be obliterated by any remastering or additional AD/conversion efforts.
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Post by Zammo February 24, 2012 (9 of 18)
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alan_dorkin said:
They sound like SACDs, as they have exactly the same data as any SACD. Just the manufacturing process has extra steps and pseudo-tech woodoo to keep the marketing department happy.
Which ones do you have out of interest?
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Lindberg said:
There's no clock involved in either CD or SACD manufacturing. In a pure production path the only clock affecting the sound is the one feeding the AD converter at the original recording sessions.
This is not entirely true. The cutting of the master disc involves converting a binary bit stream to a flashing beam of light and then mechanical action driving the pit burning laser, so inherently timing variability/jitter can get introduced. JVC's implementation slaves everything downstream of the AD step through the master disc cutting by a single clock. There is a very good explanation of of how this works on page 98:
http://www.avguide.com/buyers-guide/the-absolute-soundhi-fi-guide-cables-power-products-accessories-and-music
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