SQ: Sony SQD-2020 SQ Decoder

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I really like the DynaQuad passive speaker matrix surround sound decoding method, all you need is 1 additional speaker connected to the "+" Left and Right speaker outputs, no additional amplifiers or decoders are needed.


Kirk Bayne
 
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I had an SQD 2020 a few years back ; I also sold them when new , along with other Quadraphonic kit ( not to be confused with Quad , which is the trademark of The Accoustical Mfg Co , Huntingdon ) .

Thanks to using these when new , I clearly remember what they ‘should’ sound like , and while the one I had , more than a decade ago , operated , it did not decode correctly - I put this down to ageing of the many discrete components inside , and also the possibility that previous owners may have been inside at some point .

When I bought the unit on impulse after spotting it on eBay , I had built up a reasonable home cinema system including , amongst other items : the Sony TA-E1000ESD AV preamp with Dolby Pro Logic ( I always wondered why Sony never included an SQ mode into any of their home cinema products , given the DSP capability ) ; the SDP-EP9ES AC-3 decider ; 5x TA-N55ES Power amplifiers ; IMF TLS80II loudspeakers ( Front ) ; B&W DM2A loudspeakers ( rear ) , and a home made centre speaker using the same mid/treble units as the IMFs . I had a variety of source components ranging from my Michell Gyrodec , several Revox and Ferrograph tape recorders , video sources from U-Matic , Laserdisc , Beta , VHS , Mini DV and latterly DVD ; oh and a SonyVPH 1270QM projector .

Anyway , I connected the SQD 2020 between the relevant outputs of the AC-3 decoder and the four power amps using the discrete inputs , and an additional 2ch input from the TA-E1000 to the input for decoding SQ records .

while there was output on all channels it just never was right .

I enquired at my local Sony Centre ( where I had spent many thousands ) . Their very competent engineer looked at it and said he wouldn’t attempt it , but had made enquiries and apparently Sony Japan had one specialist engineer who still worked on these and could restore and recalibrate, but it would take many months and would be expensive . I decided not to bother and eventually sold the unit on ( with full disclosure ) .

Some time later , I tired of the AV system and went back to my roots , building instead a quality 2ch music system ( as much as anything due to pressure from the lady of the house ) .

Out went the IMFs and B&Ws ; in came my Quad ESL63 Electrostatic Loudspeakers ; all the Sony electronics , including the projector went ( I don’t even have a TV now ) and in came Quad 77 pre , CD and Tuner , and the 707 Power Amplifier ( which was designed to match the ESL63s ) ; my SME Series III pickup was upgraded to a Rega RB700 arm with AT-OC9 and I got the QC power supply for the turntable . Sold three of my five Revoxes and both Ferrographs ; keeping just a std speed 1/4tr A77 and the high speed 1/2tr B77 , plus my Uher 4200 report , Nakamichi 700 and Tascam 133 ( for use with my slide projectors ) .

That has been my kit for the last decade now and I don’t miss AV . I still have a lot of video kit in my edit suite ( I work in video production ) but for relaxation I like to listen to music and still buy records regularly .

I've now come full circle ; after selling my train set when I was about 15 to fund my first hifi system , building up to a Transcriptor Hydraulic Reference turntable , Quad 33/405 amplifier and Kefkit 3 loudspeakers , before getting into AV and home cinema .

I even have model railways in the house again , thanks to my son who is into them in a big way - so everything comes back round again .

Maybe one day I’ll add a decoder / amp plus rear speakers to my existing system , but nothing will really match the ESLs .
Sad that most will not even attempt to work on vintage quad. Sony was not the best for SQ ,Lafayette was a bit better. Audionics and Fosgate were the best for SQ, today you can get the Surround Master. I always recommend using the same speakers for front and rear. Expensive yes but worth it in the long run. I would never settle for two channel stereo!
 
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I really like the DynaQuad passive speaker matrix surround sound decoding method, all you need is 1 additional speaker connected to the "+" Left and Right speaker outputs, no addition amplifiers or decoders are needed.


Kirk Bayne
The cheap way to do it yes. Wets your appetite for real quad though. But even DynaQuad is better than no Quad at all!
 
Sad that most will not even attempt to work on vintage quad. Sony was not the best for SQ ,Lafayette was a bit better. Audionics and Fosgate were the best for SQ, today you can get the Surround Master. I always recommend using the same speakers for front and rear. Expensive yes but worth it bin the long run. I would never settle for two channel stereo!

I know the ideal is to have four identical speakers ; cost isn’t so much the issue as space , since the Electrostatics are doublets and radiate to the back equally as to the front , hence need to be at least six feet out from the wall .

That being said the concentric panels with a stepped time delay create the illusion of a point source some distance behind the panels and they produce a 3D stereo image like nothing else : this together with the complete absence of cabinet colouration is why many rate them as the best loudspeakers in the world .

When I had my AV system , it was a 5.0 system as with transmission lines there is no need for a subwoofer , I kept the five speakers as similar as possible : the B&Ws were small transmission lines with the same HF units as the IMFs , and the centre speaker I constructed also used the Coles 4001 , Celestion HF1300 and Kef B110 as in the IMFs ( although I had four of the midrange drivers in the centre speaker which allowed them to extend their response somewhat , in a wide IB enclosure ) . The Sony power amplifiers had a very low source impedance which kept the TLs under control which resulted in a complete absence of boominess , which can be a trait when partnered with lesser amplifiers .

If I did decide to add rear channels , it would be with something compact , but really I am very happy with 2ch sound which is very natural and tends to be very close to what you hear if you go to live concerts , which I’m just now starting to get out to again .

If ever looking for another decoder , it would probably be the Fosgate Tate , which I know is a scarce item , and add another Quad power amp for the rear channels . I have a few pairs of compact speakers around the house , including B&W DM5s and Rogers LS3/5a , which would be candidates , most likely the latter .
 
I really like the DynaQuad passive speaker matrix surround sound decoding method, all you need is 1 additional speaker connected to the "+" Left and Right speaker outputs, no addition amplifiers or decoders are needed.


Kirk Bayne

Yep that was the method advocated by David Hafler and also known as Hafler surround .

you are basically using the difference signal between the two channels .
 
Yep that was the method advocated by David Hafler and also known as Hafler surround .
you are basically using the difference signal between the two channels .

It is indeed a great method, I've used it for decades. I'm not remotely religious but listening to the Festival of Nine Lessons and Carols live on Radio 4 on Christmas Eve from King's College, Cambridge has become something of a tradition for me. I've just finished listening to this year's broadcast, as I often do, using one of my little Op Amp Hafler difference circuits to feed the rear amps. It is remarkable how effective this simple technique is in recreating the beautiful acoustic of the chapel in realistic way. Given material made with high quality stereo miking, and using four identical full range floor standing speakers, it frankly puts a lot of supposedly more sophisticated, 'artificial' processes to shame (and all for the cost of a £2 Op Amp and a few resistors!). Who needs Atmos?!!
 
using one of my little Op Amp Hafler difference circuits to feed the rear amps.

IMHO, it would be useful to post the schematic of your Hafler/DynaQuad (line level active) decoder (maybe in the QQ library).

I built myself a (line level active) DynaQuad decoder in the spring of 1983, I used it (with my 2 stereo receivers) until the fall of 2000 when I got a new receiver with DS decoding.


Kirk Bayne
 
IMHO, it would be useful to post the schematic of your Hafler/DynaQuad (line level active) decoder (maybe in the QQ library).

I built myself a (line level active) DynaQuad decoder in the spring of 1983, I used it (with my 2 stereo receivers) until the fall of 2000 when I got a new receiver with DS decoding.


Kirk Bayne
See this thread www.quadraphonicquad.com/forums/threads/akai-ss-1-universal-synthesizer.5331/page-4 link to the page with my schematic but check out the entire thread!
 
My reference to none use with a four channel amplifier comes from my own bitter experience and the advice of both Sony UK and the printed manuals that came with them.
I believe that the none use of headphones on these units stems from the unsatisfactory reproduction of SQ over phones, which would have been ok with discrete inputs. Sony were into promoting SQ after all.
If you want to use headphones, then get an SQD-2000.
 
SQD-2020, the quintessential SQ decoder. One is staring at me across the room. The meters look very cool with my SH-3433 scope above it. Even when I get a Tate, I will NEVER sell this piece. SQD-2020, CR80-DSS and 4DD-5 are the pieces that define an era. All three are attached to the B&K preamp on my main system.

Even though I sold this stuff back then, I don't remember SQA-100. It looks like an SQA-200 on its side. Never sold either one. We didn't stock them. Didn't sell many SQD-2020's, although I sold more of these than any outboard decoders, except the Marantz plug-in modules. I own an SQA-2B and an SQA-1. I also have an SQD-2010.

Thanks for posting this, Quadrockasaurus! It's bittersweet to see these ads. Quad had such promise at that point.

Linda
SQueaky Wheel
So do you like the 2010 or 2020 better for decoding?
 
If you want to use headphones, then get an SQD-2000.
Logic type decoders don't work well over quad headphones. Bouncing levels between two closely spaced drivers produces little effect. Lower separation decoders, those without any logic would produce a better effect, over quad phones. That sense of spaciousness is due to the ears sensitivity to phase differences, you get more of those differences by using quad phones than you do with stereo phones. The simple decoder that I described sounds great through phones, and is adjustable for the effect that you like.
 
What Linda said. HIGHLY recommended.
Well needless to say I already have one - along with the two Tates and
What Linda said. HIGHLY recommended.

oh I do already - the V2 (why do I think of 🚀 rockets??!!) as well as aAudionics of Oregon Space & Image Composer and two Tates - none of them properly set up or used much (and available to a good home) but I was wondering if it’s possible to set up the 2010 as a output monitor for the SM v2 going into my Marantz 8102 ?
 
Well needless to say I already have one - along with the two Tates and


oh I do already - the V2 (why do I think of 🚀 rockets??!!) as well as aAudionics of Oregon Space & Image Composer and two Tates - none of them properly set up or used much (and available to a good home) but I was wondering if it’s possible to set up the 2010 as a output monitor for the SM v2 going into my Marantz 8102 ?
Are you saying you’d love to send a working S&IC to my lovely abode for a mere pittance (of course I’d pay for shipping?) ‘cause I’d show it a good time? (y)
 
Sony 2020 does a better job than 2010 or Marantz SQA-2B & SQA-1, both dedicated modules which I own.

My recommendation is to get a Surround Master.
Same here on the 2020 vs. the 2010. Back when I got the 2010 I expected it to be better than my 2020, but it wasn't. I have my Surround Master hooked up through the discrete input of the 2020, so I get the benefits of the SM and the meters of the 2020.
 
Great idea. The Sony 2010 and the 2020 both have VU meters. Stereo VU meters are fascinating to watch...twice as much so with Quad!
Well I have a few receivers with meters or scopes which are both amusing but also help - a if you dare adjust the balance between front and back etc tr
Are you saying you’d love to send a working S&IC to my lovely abode for a mere pittance (of course I’d pay for shipping?) ‘cause I’d show it a good time? (y)
describe pittance? … the lamp has gone on the display but I think it’s otherwise ok. Needs someone prepared to use it properly.

I’m in Australia 🇦🇺 so shipping might be pricey too?
 
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