• QuadraphonicQuad welcomes you and encourages your participation! Treat all members with respect. Please keep all discussions civil, even when you have a strong opinion on a particular topic.

    Do not offer for free, offer for sale, offer for trade, or request copies or files of copyrighted material - no matter how rare or unavailable to the public they might be. We do not condone the illegal sharing of music. There are many places on the internet where you can participate in such transactions, but QuadraphonicQuad is not one of them. We are here to encourage and support new multichannel releases from those companies that still provide them and as such the distribution of illegal copies of recordings is counter-productive to that effort. Any posts of this sort will be deleted without notification.

    Please try to avoid discussions that pit one format against another. Hint for new users: make liberal use of the search facilities here at QuadraphonicQuad. Our message base is an incredibly rich resource of detailed information on virtually all topics pertaining to surround-sound. You will be surprised at what you can find with a little digging!

Quad 101 with a Sansui slant!

Help Support QuadraphonicQuad:

quadanasaziland

500 Club - QQ All-Star
Since 2002/2003
Joined
Mar 13, 2002
Messages
579
Location
never never land
The board is kinda slow lately so here is some thing to read that I wrote a couple of years ago for a Sansui collector forum. This is a rough history of quad with a Sansui slant that might be helpful for the folks who are coming at this from the back end (Hirez MC). You experts (u know who u are) go easy on my facts, like I said it was rough from the seat of my pants.


BadBob4747@a... wrote:
OK, Fill me in. What is variomatrix quad? I bought my first Sansui
quad
set-up, Sansui 5000X receiver andQS-500 in 1971 in Japan. I used
it for
years. Recently, I got into vintage Sansui stuff and now have an
8080DB and a
QS-800, which match up well with my Sansui 5500X , front and SP-
X7000, rear
speakers. Which units used variomatrix and what makes it superior
to the
older quad units, such as mine. I have always considered quad to
be vastly
superior to stereo. Please educate me. Thanks, Bob

Bob you pushed my quad button, your in for it now!

Ok I'm not a tech I know just enough to be dangerous, I come at this from the music
end so in simplistic terms here goes. A little history
on the thing (matrix quad) is in order to help the quadraphonicly
challenged. In the early 70's quad was ballyhooed as the next
logical step for audio. We started with mono then stereo so the next
logical step was quad. Sounds good but the problem was
that the technology was weak (matrix quad) and had not
developed enough to make it work as ballyhooed. Notable
exception was the quad reel to reel which was simple
enough cause 4 channel recordings (4 discrete channels) would be played back
on 4 channel play decks made for home use . The major record labels
saw this as they saw stereo, (eventually) when mono was it, as the next
logical step. The problem was that lp's were the media
of the day just as disc's are now. So how were they
going to get 4 channels out of a media that was great for
two channels (there is only two walls on a record
groove) there was two ways, one way was a discrete way using two bands in
the grove wall, one above
the other. The upper band holding the rear channel info called CD-4. CD-4
was developed by JVC/RCA. It was a pain in the ass to get to work well,
needed a special cartridge and a demodulator to get the rear sound.
Every thing had to be adjusted just right to get it to work and the
records tended to ware fast on most systems. My cd-4 set up works nice by the way.

Another way (actually the first way developed) was a matrixed way.
Matrix in it's simplest form is to
reverse your rear speakers. This is not quad but goofed up stereo x
2. I say this because many folks were turned off of quad by cheap
modular quad setups that did just that. In 1968 Peter Scheiber
invented a discrete circuit using caps and resisters to matrix out of
phase signals in recordings. The algorithm he first used, only
achieved 3 dbs of separation all the way around but was the base
for early quad decoders like the EV-4 (ElectraVoice) and the DynaQuad (Dynaco). When these units hit the market there was a
resounding thud! They were a step back with only 3 dbs of separation
front L-R, it was like mono x 4.
But,

Benjamin Bauer, at CBS saw some thing there and developed a way to
get 20 dbs of separation front L-R and the same 3dbs the rest of the
way around. Still using a discrete circuit. Still pretty lame but at
least it's not mono x 4. He called it SQ (Surround Quadraphonic).
At the same time Isao Itoh of Sansui was developing a very similar
system which Sansui named QS(Quadraphonic-Stereo). They were
actually first with the QS-1 in 1970. They went at it differently
Sacrificing front channel separation for diagonal separation (same 20
dbs) but it sounded more quad

Bob that is what is in your QS-800 The stated separation is 20dbs
diagonally but I think the other post is right, it was more like 10 to 13
dbs and only 3 dbs front L-R. This is what is in all the QR and QS
units plus the early and lesser QRX units like the QRX-3000
and the QRX-5500. These should be called
first generation Sansui QS units. And to clear up one of my earlier
posts, there were two versions of the QRX-5500, there was an "A"
model (QRX-5500A). It is different in that it was a hybrid of first and
a second gen. Sansui quad units (more in a moment).
In 1974 Sansui unveiled the second generation QS decoder built into
the 7001. “The” true Variomatrix system. What was new was the ic. They invented some chips to get more separation. At the same time CBS was working on improving the SQ system with some chips and did actually produce some units that are ultra rare now. It had similar results
as the Vatiomatrix but went at it a different way.
The chip Sansui invented used oral masking to get separation. Oral
masking is the principle that two sounds, one played louder than the
other, the louder signal is what you hear. The softer is masked by
the way our mind reacts to sound. So here’s kinda how it works, this
is after the basic decoding is already done on the out of phase
signals (the diffuse sounding stuff that doesn't seem to be coming
from one speaker). The Sansui chip looks for the loudest signal
and amps it a little at the same time masking it
in the other channels. This is done very fast by the IC and makes it
sound very discrete. This scheme achieves 20dbs front L-R (as good as many decent carts) and the same front to back and back L-R but the diagonal separation was 35dbs, VERY QUAD! 35dbs of separation is better than just about any cart and good enough to sound almost discrete to your brain.

There is three chips on the quad board in the Sansui 2nd gen. units
and only two in the QRX-5500A. The 3rd missing chip step was still
handled by a discrete circuit. Because of this the front to back and
back L-R separation was only about 10 dbs. This hybrid board is also in
the 7500A. The QRX 5001, 6001, 7001, 8001, 9001, 777 and the
999 as well as the QSD-1, D-2 and D-1000. All had second gen boards.

Up to this time the other manufacturer were concentrating on SQ
decoding because CBS wanted it that way (their format) and because
they had many more titles. So a standard was never chosen in the US
but in Japan QS was chosen as the standard quad format even though
JVC had CD-4. SQ (CBS) wouldn't submit their format to the
determining board (format war). The best the other manufacturers
could come up with were logic circuits for decoding (Pioneer,
Kenwood, Sony so on) not much better then first gen. Sansui quads.
Sansui was way ahead of their time! Not until 1979 did Jim Fosgate
come out with the Space and Image Composer (later stripped down and
called the Tate II) that did for separation on SQ what Variomatrix
did for QS but that is a whole other story.

Alas quad was dying in 1975 due to the format war (sq vs qs vs cd-4)
and lame decoding just when these guys were getting it figured out.

So 20 dbs of separation all around (like a decent cart.) and 35 dbs
diagonally for QS encoded material, very quad! Almost as discrete
(to your brain) as 4 channel tape (rtr & quad 8track). Again, this
is with a good cart; that is setup correctly. If the cart has only
16 dbs of separation then every thing is reduced.
That's great but who has QS encoded records (me about 45 or so) and
what did come out is old now (there was some great stuff though like
Pink Floyd, Steely Dan, Joe Walsh to name a few). So what's the big deal?
Variomatrix in the quad synth mode gets the same results from stereo
material! Stereo material that is recorded using a lot of complex
phasing makes the Variomatrix system sing! And now with the one's
and zero's of the digital age via the cd, stereo separation is
discrete so the decoding is better now then Sansui ever dreamed. For
example, remember Thomas Dolby's "She Blinded Me With Science"? Very
complex phasing technics in the mix, he was quite the wizard. This
cd sounds so quad as to rival PF's DSOTM that Alan Parsons mixed
with quad as the format. The stereo version of DSOTM was mixed down
from the quad masters. So any thing by Alan Parsons, Steve Miller,
Rush, Hendrix on and on, any one putting out of phase stuff in their
recordings, the variomatrix circuit eats up! This would include just
about every thing recorded now.

Just about every thing goes better with Coke er Variomatrix!

My QSD-1 (standalone high end decoder) has three sets of quad
boards for the three bands, bass , mid, treble so it can perform the
oral masking on three things at the same time, say low bass or
drums, midrange- guitar, vocals so on and any thing out of phase on
the high end. End result is smoother but barely noticeable in a
blind fold test.

Sansui quad hybrid owners don't despair! They were better then any
thing else by far and are great still at synthing quad, the
QRX-01 units were just better. Which makes me wonder
why any one buys any thing quad on ebay other than Sansui?

Well there you have it more then you then you ever wanted to now
about Sansui quad.

Thanks to QB and others for the education over the years! :worhty
 

Mansui QRX5500

New member
Joined
Dec 12, 2007
Messages
9
thanks quadanasaziland for all the detailed info.

I'm a newbie to the quad world, but the bug has definitely bitten me. I've started with a few ebay purchases:

Sansui QRX5500 (i was wanting a 5500A but just couldn't find the right one)
Concord CD8-4 8track player
Pink Floyd's DSOTM Q8

The QRX5500 had a little scratchiness on both front and rear right channels, me and my friend found a blown fuse inside and now I'm just waiting for that to come from ebay too. hopefully it fixes the problem.

now i just have a few question about the variomatrix:

i'm still a little confused about what QS decoder my QRX5500 has? i know its not the best one, but I just love all the other features only present on the 5500, such as the direction knob, the 4x double knobs for bass and treble so you can change bass and treble for each individual channel, as well ass the four individual meters for each channel.

There is three chips on the quad board in the Sansui 2nd gen. units
and only two in the QRX-5500A. The 3rd missing chip step was still
handled by a discrete circuit. Because of this the front to back and
back L-R separation was only about 10 dbs. This hybrid board is also in
the 7500A. The QRX 5001, 6001, 7001, 8001, 9001, 777 and the
999 as well as the QSD-1, D-2 and D-1000. All had second gen boards.
do this mean my QRX5500 has a first gen QS board? I really like the idea of getting some cool synthed quad effects from my collect of stereo recordings as mentioned here:

So what's the big deal?
Variomatrix in the quad synth mode gets the same results from stereo
material! Stereo material that is recorded using a lot of complex
phasing makes the Variomatrix system sing! And now with the one's
and zero's of the digital age via the cd, stereo separation is
discrete so the decoding is better now then Sansui ever dreamed.
which QS board do you need to "make the variomatrix sing" from stereo recordings? if my QRX5500 doesn't have it could I get the same effect from QSD-1 as mentioned?


oh, and just two more questions:

1. Is the Concord CD8-4 ok for Q8's? I picked it up BIN on ebay for $23.00, so I couldn't resist....

2. I've seen some talk about a UK Q8 of Pink Floyd's DSOTM, what is the other version? what makes the UK version so much better? and how do I tell what version I have?

sorry for the lengthy post, but setting up quad is a little daunting at first, but I have a feeling based on all the enthusiasm here that it'll be worth it!

thanks
 

quadanasaziland

500 Club - QQ All-Star
Since 2002/2003
Joined
Mar 13, 2002
Messages
579
Location
never never land
i'm still a little confused about what QS decoder my QRX5500 has? i know its not the best one, but I just love all the other features only present on the 5500, such as the direction knob, the 4x double knobs for bass and treble so you can change bass and treble for each individual channel, as well ass the four individual meters for each channel. do this mean my QRX5500 has a first gen QS board? I really like the idea of getting some cool synthed quad effects from my collect of stereo recordings as
mentioned here:
Yea the 5500 decoding boards are first generation, wires, caps and transistors but it and the 6500 and 7500 are cool units with lots of features.
which QS board do you need to "make the variomatrix sing" from stereo recordings? if my QRX5500 doesn't have it could I get the same effect from QSD-1 as mentioned?
The 5500a and 7500a (hybreds) are better at synthing quad than Technics, Pioneer, you name it. Some may take offence to this statement but it just comes down to brass tacks ie intenal componets. That said the (A) models cant do what the QRX-01's, 777, 999, D-1, D-2 and D-1000 units can! The receiver units and the D-2 have one board so does the D-1000 but it has FETS that make it faster. The QSD-1 has three boards and is considered the best of the best!

Dont know about the Concord but if it's working it should be ok as your talking about 4 channel tape, hard to screw that up. The USA DSOTM Q8 has a track change during Money, The UK doesn't. Check the cart to see where it was made. Hope this helps!

Thanks Jon! I've been Stickyfied:)
 

Mansui QRX5500

New member
Joined
Dec 12, 2007
Messages
9
thanks again quadanasaziland.

just to make sure I got this all right...

so basically my 5500 will synth quad from stereo recordings, but not as well as the A models or the QRX 001's ect ect?

so if I got my hands on a QSD-1 then I still have the QRX5500 like I want, and have the best possible QS decoding and synthing quad from stereo??

any ideas on where I could find a QSD-1 and what it might cost??

how about the QS-1? if I'm more into synthing rather than decoding would this work OK?
 

quadanasaziland

500 Club - QQ All-Star
Since 2002/2003
Joined
Mar 13, 2002
Messages
579
Location
never never land
thanks again quadanasaziland.

just to make sure I got this all right...

so basically my 5500 will synth quad from stereo recordings, but not as well as the A models or the QRX 001's ect ect?

so if I got my hands on a QSD-1 then I still have the QRX5500 like I want, and have the best possible QS decoding and synthing quad from stereo??

any ideas on where I could find a QSD-1 and what it might cost??

how about the QS-1? if I'm more into synthing rather than decoding would this work OK?
Qsd-1 and a 5500 would be a sweet setup! I have a QuadBob restored and moded D-1 that I am considering parting with that said I have been considering it for a couple of years. When I do decide to part with it, it wont be cheap. The QS-1 is a first generation decoder. It doesnt matter if you are decoding or synthing it's all the same as far as the units capability, 1st generation is 1st generation.
 

RenoKen

Member
Joined
Aug 13, 2007
Messages
36
Location
Reno, NV
Thanks for the review. Sort of followed the developmenmt during the 70s when I was overseas in the Air Force, but had forgotten the details.
Ken
 

jsrstereo

Senior Member
Since 2002/2003
Joined
Jan 22, 2003
Messages
210
Location
oklahoma city
Here are a couple question regarding the "Hall" setting on my QRX VarioMatrix decoder:

I understand that the Hall setting passes the in-put signal un-altered to the front channels, and that the rear channels get the extracted out-of-phase portion of the in-put signal, but with just enuff blend from the in-phase (mono) portion of the in-put to create a subtle stereo surround field for the rear.

Question #1: is any part of the above statement incorrect? If so, then just what is going on with "Hall" as opposed to the active logic steering of the "Surround" setting?

Question # 2: is there any logic steering at all going on with any portion of the signals in the "Hall" setting?

Thanks from John
 

jsrstereo

Senior Member
Since 2002/2003
Joined
Jan 22, 2003
Messages
210
Location
oklahoma city
Here are a couple question regarding the "Hall" setting on my QRX VarioMatrix decoder:

I understand that the Hall setting passes the in-put signal un-altered to the front channels, and that the rear channels get the extracted out-of-phase portion of the in-put signal, but with just enuff blend from the in-phase (mono) portion of the in-put to create a subtle stereo surround field for the rear.

Question #1: is any part of the above statement incorrect? If so, then just what is going on with "Hall" as opposed to the active logic steering of the "Surround" setting?

Question # 2: is there any logic steering at all going on with any portion of the signals in the "Hall" setting?




Thanks from John


Bump
 

quadanasaziland

500 Club - QQ All-Star
Since 2002/2003
Joined
Mar 13, 2002
Messages
579
Location
never never land
Yea just the straight stereo feed to the front channels and any thing OOF to the rears. Band/ball team in the foreground, croud in the rears, great if you want that LIVE feel. Only steering would be the OOF stereo info to the correct rear channel.



Here are a couple question regarding the "Hall" setting on my QRX VarioMatrix decoder:

I understand that the Hall setting passes the in-put signal un-altered to the front channels, and that the rear channels get the extracted out-of-phase portion of the in-put signal, but with just enuff blend from the in-phase (mono) portion of the in-put to create a subtle stereo surround field for the rear.

Question #1: is any part of the above statement incorrect? If so, then just what is going on with "Hall" as opposed to the active logic steering of the "Surround" setting?

Question # 2: is there any logic steering at all going on with any portion of the signals in the "Hall" setting?

Thanks from John
 

Disclord

900 Club - QQ All-Star
Joined
May 19, 2005
Messages
944
Location
Plattsburg, MO (just outside Kansas City)
Just thought I'd add some info in regards to SQ...

CBS and Motorola created a 3-chip set for full-logic SQ decoders - one chip did the SQ dematrixing (it was a horrid 3-pole design and was used by almost every mass manufacturer of SQ equipment), one chip did the directional detection (Wavematching) and the final chip contained the 4 VCA's that raised or lowered the front/back volume as required - when implemented all together, the decoder was a Full-Wavematching with Front/Back Logic decoder. In 1974, the Front/Back Logic was dropped and CBS' "Vari-Blend" Logic was substituted. So the decoder would be a Full-Wavematching w/Vari-blend decoder. Only the rear channels were blended together to eliminate the CF signal... CB signals appearing in the front were left alone, unlike the Front/Back logic, where they were eliminated. Sony produced their own IC that did Wavematching and Vari-blend on a single chip. Layfette Radio was the first company to make a stand-alone Full-Wavematching SQ decoder that had the Vari-Blend circuit (the SQ-W). The Sony SQD-2020 was the first Full-Wavematching w/Front-Back Logic decoder offered to the public (it used 100% discrete circuitry too) - it was also sold to the professional market as a 'companion' piece to the SQE-2000 SQ Encoder. The CBS Full-Logic decoders were slow-slow-slow (50-100 millisecond attack times!!!) and had very audible logic artifacts, while the SQD-2020 had a super-fast 3ms attack time and much reduced artifacts. Sony planned to eventually introduce the SQE-2000 encoder to the consumer market, but had a 2-year "exclusivity" deal with CBS to supply it to them for resale first. The phase shifters in both the SQD-2020 and the SQE-2000 are 5-Pole. (The Fosgate 101A is 6-pole, the Audionics is 8-pole). Anyway, due to declines in the quad marketplace, the SQE-2000 was never sold to consumers - interestingly, Jim Fosgate used the Sony SQE encoder to create test recordings when designing the 101A Tate II decoder. Sony never produced an SQ Position Encoder - only CBS Labs did. All CBS Labs designed SQ encoders/decoders used precision-aligned 10-pole phase shifters with no more than 1 degree of phase error. For the consumer decoders, the only 'standard' CBS had was a maximum phase error of 20 degrees - they had NO standards for sound quality, logic attack/release times, minimum channel separation, etc... it was up to each company to design their SQ decoder how they wanted it... Dolby Lab's would never allow such a thing to happen!!!

The CBS/Motorola IC's were also second-sourced by Fairchild Semiconductor. In Japan, Sony came out with a selective cancellation-based SQ decoder, akin to the CBS Paramatrix, but it was never released in the USA or anywhere else but Japan. The CBS SQ Matrix WAS standardized in Japan - it and QS were "co-standards."

BTW, Sansui had an agreement with Hitachi to make the Vario-Matrix IC's available to any 3rd party company that wanted QS Vario-Matrix in their product, but there were so few QS encoded albums available in America that no company took them up on it. Back in 1989, when Sansui was still around, I talked to one of their engineers who told me that they (Sansui) still had very large quantities of the QS Vario-Matrix chips available - I ended up buying a full set of them directly from Sansui for $19.00.
 

Wagonmaster_91

300 Club - QQ All-Star
Since 2002/2003
Joined
Mar 11, 2002
Messages
372
Location
Dallas,TX
Disclord, since you brought up the Sony SQE2000 maybe you (or someone on the board) can answer a couple of questions about that unit.

First, on the left rear of the unit there is a knob with four settings for the SQ Mode : Normal, INT, F.O. and B.O.
Do you know what these mean?


Second, on the right rear there is a 12+ DC input (or is it an output?). What is that for?

Thanks,
Mark
 

Attachments

jdmack

1K Club - QQ Shooting Star
QQ Supporter
Joined
Feb 27, 2005
Messages
1,221
Location
Maryland
First, on the left rear of the unit there is a knob with four settings for the SQ Mode : Normal, INT, F.O. and B.O.
Do you know what these mean?
I would guess that "F.O." and B.O." mean "Front Only" and "Back Only." "Normal" might mean no decoding, or it might mean normal SQ decoding. Not sure what "Int" would mean.

J. D.
 
2
Group builder
Top