New Surround Master coming! Its a jump to the left and a step to the right

[DuncanS]

I've been musing on SM Involve Mode and CD4.

CD4 is essentially two FM stereo stations on an LP, so LF+LR/RF+RR as 2 baseband channels, and LF-LR/RF-RR channels FM'ed above the 30kHz carrier (if I remember correctly). So maybe Involve Mode 'could' extract 'surround information from the summed LF+LR & RF+RR baseband channels?

 

[chucky3042]

I've been musing on SM Involve Mode and CD4.

CD4 is essentially two FM stereo stations on an LP, so LF+LR/RF+RR as 2 baseband channels, and LF-LR/RF-RR channels FM'ed above the 30kHz carrier (if I remember correctly). So maybe Involve Mode could extract surround information from the summed LF+LR & RF+RR baseband channels?

Yes thats whats happening but to get the reported great results, such a signal will be "as flat as a tack". I suspect they snuck in a partial matrix eg LF' = Lf +0.2Rf (-90 degrees). Kinda SQ light, sneaky but it would decode well and sound very stereo.

Just sayin

Chucky

 

[DennisMabry]

I have an electronic tech who is going to look at it for me. I would like to know what the problems are so that I might save him some troubleshooting time. Do you know what they are? I read on another forum that some of the components had values too low in ratings for the current involved.

Sorry, do not have a clue. Did you try contacting DT directly?

 

[Soundfield]

Yes thats whats happening but to get the reported great results, such a signal will be "as flat as a tack". I suspect they snuck in a partial matrix eg LF' = Lf +0.2Rf (-90 degrees). Kinda SQ light, sneaky but it would decode well and sound very stereo.

Just sayin

Chucky

You are getting perilously close to re-inventing the UD-4 system (which made CD-4 look successful)!!

 

[DuncanS]

Yes thats whats happening but to get the reported great results, such a signal will be "as flat as a tack". I suspect they snuck in a partial matrix eg LF' = Lf +0.2Rf (-90 degrees). Kinda SQ light, sneaky but it would decode well and sound very stereo.

Just sayin

Chucky

Interesting, they wouldn't have to worry about Mono compatibility so I wonder if a bit of partial matrix would help with the final decode?

 

[chucky3042]

Interesting, they wouldn't have to worry about Mono compatibility so I wonder if a bit of partial matrix would help with the final decode?

Not sure what you mean.......... Please explain?

 

[DuncanS]

Not sure what you mean.......... Please explain?

I was wondering that maybe you could 'loosen' the phase requirements of the filters for the FM decode/downmixer/matrix section if you did that - probably complete b*ll*cks.

In the past I've simplified some more difficult analogue circuitry by making the 'easy' part slightly more complex. If I remember correctly (it was quite some while ago!) I did some trade offs when designing an analogue Hilbert Transformer to remove negative frequencies.

 

[chucky3042]

I was wondering that maybe you could 'loosen' the phase requirements of the filters for the FM decode/downmixer/matrix section if you did that - probably complete b*ll*cks.

In the past I've simplified some more difficult analogue circuitry by making the 'easy' part slightly more complex. If I remember correctly (it was quite some while ago!) I did some trade offs when designing an analogue Hilbert Transformer to remove negative frequencies.

Ah. What I am getting at is by watering down the phase content the stereo downmix would have been close to indistinguishable from the plane vanilla stereo on the CD4 recordings with no apparent stereo image compression (again 12 dB is attained), then decode by a really good surround QS decoder eg the Sansui this would then result in around 12 db surround decode also (again 12 db attained). No one looses. This is why I would like to examine the tracks of a CD4 recording and look at the Left / right bleed through and see if they were being sneaky.

 

[dwight]

Ah. What I am getting at is by watering down the phase content the stereo downmix would have been close to indistinguishable from the plane vanilla stereo on the CD4 recordings with no apparent stereo image compression (again 12 dB is attained), then decode by a really good surround QS decoder eg the Sansui this would then result in around 12 db surround decode also (again 12 db attained). No one looses. This is why I would like to examine the tracks of a CD4 recording and look at the Left / right bleed through and see if they were being sneaky.

Dear Big Aussie Number One, Yeah, I know it's a revision....anyway....The RCA Quadradisc has this written on the cover: This compatible stereo/4-channel record is designed for performance on stereo or discrete qudraphonic systems, including CD4 systems. Don't you find that strange? It sounds like CD-4 is a second choice for discrete quad. On Electra Records it says: This four channel discrete quadradisc is fully compatible. All rear channel information will sound in the front speakers when played in stereo. I think SOUNDFIELD pointing to UD-4, which had a matrix built in for recovery, may be something to contemplate. Also I pulled the standard NILSSON SCHMILLSON RCA record from my garage, and the fidelity of the standard stereo record, like the CD, was wonderful, putting the CD4 to shame.
Yankee Doodle Dandy

 

[rustyandi]

I haven’t played a CD4 Record as a matrix disc before
So I pulled out Jerry Reed Lord mister Ford CD4
It has a guitar start that goes a full circle around the 4 channels
Played through the Involve Decoder it gives an approximation
Of a circle but not as good
Then I played through S/Master SQ
The Guitar just moved from the left to right front channels
Very little in the rears
I have other Stereo LPs that give movement from front to rear
My impression is that the Involve is giving the same resalts
On the CD4 LPs as it does on Stereo
There is nothing wrong with that

 

[chucky3042]

Dear Big Aussie Number One, Yeah, I know it's a revision....anyway....The RCA Quadradisc has this written on the cover: This compatible stereo/4-channel record is designed for performance on stereo or discrete qudraphonic systems, including CD4 systems. Don't you find that strange? It sounds like CD-4 is a second choice for discrete quad. On Electra Records it says: This four channel discrete quadradisc is fully compatible. All rear channel information will sound in the front speakers when played in stereo. I think SOUNDFIELD pointing to UD-4, which had a matrix built in for recovery, may be something to contemplate. Also I pulled the standard NILSSON SCHMILLSON RCA record from my garage, and the fidelity of the standard stereo record, like the CD, was wonderful, putting the CD4 to shame.
Yankee Doodle Dandy

Hey Yankee Doodle Dandy

You really are not as silly as you look. Have a gander at what Wiki says about UD 4: I think we are on to something!

UD-4


From Wikipedia, the free encyclopedia

UD-4 was a discrete four-channel quadraphonic sound system for phonograph records introduced by Nippon Columbia (Denon) in 1974. This system had some similarities with the more successful CD-4 process introduced by JVC and RCA in 1972.
Only about 35 to 40 LP album titles were encoded in this format, and it was marketed only in the UK, Europe and Japan. Most of these releases were marketed by the Denon label.
The UMX standard used for UD-4 contains two subsystems, BMX, a basic 4-2-4 matrix decoder (different from QS Regular Matrix), and QMX, a 4-4-4 system. UD-4 is the process of modulating QMX onto a record with a process similar to CD-4, but also matrix encoded.
A BMX decoder could be used to play back UD-4 recordings, but, by adding a special phono cartridge and a specialized UD-4 demodulator, two supplementary channels could be extracted and used to enhance directional resolution.
UD-4 systems first encoded the four original channels into four new channels. Two of these new channels contained the original four channels, matrix encoded. The other two contained only band-limited localization information, and were encoded with high frequency carrier signals similar to the CD-4 system.
The system suffered from incompatibility with regular stereo playback due to phase differences between the left and right channels.[1]
Phono cartridge set-up for UD-4 playback was less critical than in CD-4, because the high frequency carrier signals were not as high as those found in the CD-4 system.[2]



Love in a sloppy bucket

Big Aussie number 1

 

[chucky3042]

Hey RustyandI and Yankee Doodle Dandy

Its just like old times again - the three of us musketeers are on the same page again!!!! Have to meet up again at Ron's place one day.

 

[dwight]

Hey Yankee Doodle Dandy

You really are not as silly as you look. Have a gander at what Wiki says about UD 4: I think we are on to something!

UD-4


From Wikipedia, the free encyclopedia

UD-4 was a discrete four-channel quadraphonic sound system for phonograph records introduced by Nippon Columbia (Denon) in 1974. This system had some similarities with the more successful CD-4 process introduced by JVC and RCA in 1972.
Only about 35 to 40 LP album titles were encoded in this format, and it was marketed only in the UK, Europe and Japan. Most of these releases were marketed by the Denon label.
The UMX standard used for UD-4 contains two subsystems, BMX, a basic 4-2-4 matrix decoder (different from QS Regular Matrix), and QMX, a 4-4-4 system. UD-4 is the process of modulating QMX onto a record with a process similar to CD-4, but also matrix encoded.
A BMX decoder could be used to play back UD-4 recordings, but, by adding a special phono cartridge and a specialized UD-4 demodulator, two supplementary channels could be extracted and used to enhance directional resolution.
UD-4 systems first encoded the four original channels into four new channels. Two of these new channels contained the original four channels, matrix encoded. The other two contained only band-limited localization information, and were encoded with high frequency carrier signals similar to the CD-4 system.
The system suffered from incompatibility with regular stereo playback due to phase differences between the left and right channels.[1]
Phono cartridge set-up for UD-4 playback was less critical than in CD-4, because the high frequency carrier signals were not as high as those found in the CD-4 system.[2]



Love in a sloppy bucket

Big Aussie number 1

You know, you are wrong saying I'm not as silly as I look! I'm much sillier. I should have bought tons of CD4s. After paying all that money for the JVC and the Audio Technica with Shibata and falling in love with the Carly Simon's YOUR SO VAIN and the SCHMILLSON album, for some reason I gave up on the system. Of course it's forty some years ago and hard to understand certain decisions made. Rustyandi gave less than a lukewarm nod to CD4 matrix results....and I'm assuming he could do a real time AB test....he used the word approximation....and he knows what he's talking about. I can only say perhaps it varies from record to record. The four corner guitar riffs on VAIN and the effects on SCHMILLSON are very clear and concrete. I guess the best that can be said is that it is to be determined.
Silly Doodle Dandy

 

[dwight]

You know, you are wrong saying I'm not as silly as I look! I'm much sillier. I should have bought tons of CD4s. After paying all that money for the JVC and the Audio Technica with Shibata and falling in love with the Carly Simon's YOUR SO VAIN and the SCHMILLSON album, for some reason I gave up on the system. Of course it's forty some years ago and hard to understand certain decisions made. Rustyandi gave less than a lukewarm nod to CD4 matrix results....and I'm assuming he could do a real time AB test....he used the word approximation....and he knows what he's talking about. I can only say perhaps it varies from record to record. The four corner guitar riffs on VAIN and the effects on SCHMILLSON are very clear and concrete. I guess the best that can be said is that it is to be determined.
Silly Doodle Dandy

I'll never forget Rustyandi and his audio lair......so very cool.

 

[chucky3042]

I'll never forget Rustyandi and his audio lair......so very cool.

Its a very manly cave indeed

 

[rustyandi]

Hey Yankee Doodle Dandy

You really are not as silly as you look. Have a gander at what Wiki says about UD 4: I think we are on to something!

UD-4


From Wikipedia, the free encyclopedia

UD-4 was a discrete four-channel quadraphonic sound system for phonograph records introduced by Nippon Columbia (Denon) in 1974. This system had some similarities with the more successful CD-4 process introduced by JVC and RCA in 1972.
Only about 35 to 40 LP album titles were encoded in this format, and it was marketed only in the UK, Europe and Japan. Most of these releases were marketed by the Denon label.
The UMX standard used for UD-4 contains two subsystems, BMX, a basic 4-2-4 matrix decoder (different from QS Regular Matrix), and QMX, a 4-4-4 system. UD-4 is the process of modulating QMX onto a record with a process similar to CD-4, but also matrix encoded.
A BMX decoder could be used to play back UD-4 recordings, but, by adding a special phono cartridge and a specialized UD-4 demodulator, two supplementary channels could be extracted and used to enhance directional resolution.
UD-4 systems first encoded the four original channels into four new channels. Two of these new channels contained the original four channels, matrix encoded. The other two contained only band-limited localization information, and were encoded with high frequency carrier signals similar to the CD-4 system.
The system suffered from incompatibility with regular stereo playback due to phase differences between the left and right channels.[1]
Phono cartridge set-up for UD-4 playback was less critical than in CD-4, because the high frequency carrier signals were not as high as those found in the CD-4 system.[2]



Love in a sloppy bucket

Big Aussie number 1

The Matrix on UD4 is very close to UHJ I have played a lp by TAG that has a sound that goes around the channels played with a a UHJ decoder when I played the same LP on the UD100 Denon UD4 decoder as a matrix system it decoded the same

 

[bigbillquad]

Hi. All

I thought I might get into this CD-4 to Matrix thing because I have never played a CD-4 disk as a Matrix QS play, so I have put together a view CD-4 disks I can`t play them through my SMv2 because I have it connected to my Denon, so I played them through my Sansui QRX 777 QS I used my JVC CD4-50 Demodulator & my Victor QL-3F with a JVC CD-4 cartridge turntable.
I listened to a view disks and the last one was Enoch light brass menagerie these disc`s have a very discrete music especially Enoch`s one instruments in each corner in CD-4 mode very discrete listening then turned the Demodutator to Stereo and then switch to QS and found the orientation of the music was the same not as discrete and the volume was lower than the CD-4 output, I was very surprised on the results, I would say the SMv2 would do much better job than my Sansui QRX 777 would do .
BBQ...

 

[chucky3042]

Dear all

I have been doing some background investigation on the new SM V2 and I will be advising all of some findings shortly but as a general operational note, it is better to operate the thing with the main input level knob as fully advanced clockwise as possible to just below the onset of the clipping light. If you are dumb like me you will be setting the thing with all knobs at 12 o clock by habit - not right. Doing the fully clockwise thing will optimise the decode operation, distortion and signal to noise ratio.

Regards

Chucky

 

[Sonik Wiz]

Dear all

I have been doing some background investigation on the new SM V2 and I will be advising all of some findings shortly but as a general operational note, it is better to operate the thing with the main input level knob as fully advanced clockwise as possible to just below the onset of the clipping light. If you are dumb like me you will be setting the thing with all knobs at 12 o clock by habit - not right. Doing the fully clockwise thing will optimise the decode operation, distortion and signal to noise ratio.

Regards

Chucky

Well that's interesting.
For myself I have a Chase RLC-1 as a front end as posted in another note. Among other features it has an level output control. I leave the SM v2 input level at max & adjust to just under clipping with the Chase. Sound good or any other suggestions?

 

[Soundfield]

it is better to operate the thing with the main input level knob as fully advanced clockwise as possible to just below the onset of the clipping light.

Yes, I'd assumed that was how you were supposed to set it!