SQ: Sony SQD-2020 SQ Decoder

[patwalsh]

is the SQD-2020 compatible for a quad turntable? I can't imagine its not, but I don't see a phone input on back.... need help

 

[cupboy]

is the SQD-2020 compatible for a quad turntable? I can't imagine its not, but I don't see a phone input on back.... need help

High level inputs only. Plug turntable into preamp or receiver and plug tape output into the decoder.

 

[patwalsh]

@cupboy - not sure I follow, what I am looking to do is replace my JVC cd-4 demodulator with the Sony since it decodes SQ as well as cd-4 discrete. The JVC has phono input for red\white RCA cables and 4 channel out - that goes to the 4 AUX inputs on the back of my receiver.

On the Sony - can I plug my turntalbe into the front preamp input - and then would the output - high\low left\right go to the AUX inputs on my receiver? would this set up give me both quad formats SQ and CD4 discrete, depending on which setting is chosen on the front?

That make sense??

 

[patwalsh]

I actually think I got it now.. does the rca cables from the turntable go directly tot he receiver, phono input, then from the receiver pre amp out to the Sony SQD-2020 pre amp input, and then the would the output - high\low left\right go to the AUX inputs on my receiver? would this set up give me both quad formats SQ and CD4 discrete, depending on which setting is chosen on the front?

am I getting close?

 

[Owen Smith]

I doubt the SQD-2020 decodes CD-4 at all.

 

[patwalsh]

Why do you say that Owen? there are 4 selecter buttons on the front and there is a discrete option.. I don't know - I am looking for inout from people in the quad world who have one.

 

[Owen Smith]

Why do you say that Owen? there are 4 selecter buttons on the front and there is a discrete option.. I don't know - I am looking for inout from people in the quad world who have one.

There is a posting earlier in this thread with a link to the SQD-2020 manual, you could download it. I believe it takes a 4 channel input (from Q4, Q8 or CD-4) and passes it to the outputs. So you could connect the output of the CD-4 demodulator to the SQD-2020 discrete input.

 

[DuncanS]

Why do you say that Owen? there are 4 selecter buttons on the front and there is a discrete option.. I don't know - I am looking for inout from people in the quad world who have one.

I just had a look at the manual link Circular Vibes gave in #79, and I'd agree with Owen. I'd say the discrete selector is for a 4 channel input pass through, as in from a tape machine, not for CD-4 demodulation. I would expect to see a pilot tone indicator on a CD-4 demodulator.

 

[Circular Vibes]

The discrete button on your SQD 2020 is for a discrete input, which means that you can plug in a 4 channel input such as a tape deck or the output from a CD4 demodulator or the leads from a 4 channel turntable such as the ones from Panasonic that had a demodulator built in. It will not demodulate CD4 discs for you. I have the same decoder in my system, if it did CD4, I would not have a need for another piece of gear. The SQD 2020 is not a pre amp, it goes on a tape loop. You still need to plug your turntable into a phono input or pre amp.

 

[patwalsh]

Thanks guys - that's exactly what I needed to know.. Is there a product out there that decodes both SQ and CD4 discrete?

 

[John Svensson]

Short answer is "Yes". There were four channel receivers which had a built-in CD4 demodulator, and most or all would have featured some sort of SQ decoder circuit also. Probably neither one would have been optimal though, i.e.,Tate's never came as part of an integrated amp. If you have a bunch of CD4 and SQ records and your budget allows.... your best bet would be to get a good multi-channel amp, an outboard CD4 demodulator, and a new Involve unit to play your SQ/QS vinyl.

 

[The Bushmaster]

Sanyo DCX-3500K (receiver) has a decent SQ decoder and a decent CD 4 demodulator. Not the best but, good.

 

[patwalsh]

I can not figure out how to connect mine correctly. I am relatively new to the quad world. I have tried the turntable to the Phono 1 on my receiver (Pioneer QX 8000) and then from the every 'out' on the receiver to the SQ Decoder Sony 2050, and then the output on the decoder to the aux ports on the receiver. I have tried from the turntable to the decoder and than from the decoder to the aux ports on the receiver... I can not get this to work - I have tried every connection scenario possible (I think) I can get stereo output, but not quad...

I have a CD-4 discreet demodulator and its pretty simple - RCA jacks from the turntable to the input on the demodulator and 4 channel out to the aux ports on the receiver - front and rear amp... works great. but I cant get this to do the same.

Are these SQ decoders only for recording to tape decks? am I missing something?

Thanks for helping

 

[patwalsh]

here is the back of my receiver...

 

[soundcentre]

Greetings from England Pat,

It is amazing but that history repeats itself over forty years after I bought the brand new Pioneer QX8000!

If you have read my previous comments on this subject in this thread you have your answer.

The Sony decoders, (mine were SQD2020 and SQD2010 and still are), they did not work as intended through the QX8000 or any other receiver I have tried.

Currently this is two Sansui QRX9001's and the same goes for the Sansui QSD2 if used with a receiver.

These SQ or in the case of Sansui QS decoders were intended to be add on units to an existing stereo system in the early to mid 1970's.

If your Sony SQ decoder is used with two separate stereo amplifiers as intended in the instruction manuals supplied (at least here in England) then all is well.

I was given this information by a Sony service engineer in the 1980's when I purchased the service manuals.

Apparently the department made money from repairing the damage caused to four channel decoders after the guarantee ran out!

By comparison a CD-4 demodulator will work well with your QX8000. I just hope that you do not suffer capacitor breakdown as I did over five years with mine.

Pioneer made an SQ decoder called QD210 and I still have the letter from the importer, advising me to buy one to play SQ records with, back around 1973.

Suffice it is to say that it did not work properly which is the problem that you are having now.

If you have the equipment to try your SQ decoder with two stereo amplifiers and four loudspeakers you may be pleasantly pleased.

I hope so and best of luck.

David

 

[patwalsh]

David - Greetings from New York

Thanks very much for detailing out everything for me. I missed the earlier comments. I am having great results with my QX8000 and CD-4 demodulator. I know the QX8000 isnt as highly ranked like some of the high echelon quad receivers, but I really do like it. Not that I wouldn't want to upgrade, but I am happy with it. What did you think of yours? Do you still have it or has it been replaced long ago.

Thanks,
Pat

 

[patwalsh]

David - Greetings from New York

Thanks very much for detailing out everything for me. I missed the earlier comments. I am having great results with my QX8000 and CD-4 demodulator. I know the QX8000 isnt as highly ranked like some of the high echelon quad receivers, but I really do like it. Not that I wouldn't want to upgrade, but I am happy with it. What did you think of yours? Do you still have it or has it been replaced long ago.

Thanks,
Pat

 

[soundcentre]

Greetings again Pat,

I bought the QX8000 in September 1972 as a first move into quadraphonic sound, having seen it advertised in Malta in 1971 and becoming available in England around the same time.

It gave much trouble in terms of tantalum capacitor breakdown and after several trips to Shriro UK Limited, later called Pioneer UK, it must have been the only one with an all UK made line up of capacitors.

I sold it and the Pioneer QD210 SQ decoder when I upgraded the receiver in 1977 for the Sansui QRX9001.

In terms of its sound it was by comparison to the later designs, like listening to a kitchen transistor radio having a very coloured sound. The decoding of four channel records was virtually non existent and what I needed was something which decoded them and sounded much better. The advancement of electronics in amplifiers in the period especially from Japan being very marked indeed.

It was also disappointing to buy at £200 a new tuner amplifier as we called them back then, only for it to be replaced with the QX8000A with the QD210 inside it, instead of the so called Quadraliser. This latter was a basic 3db regular matrix not dissimilar to Sansui QS in its original form.

When sold by me in 1977 it was working better than it had previously by virtue of all the capacitors having been changed and something which Pioneer UK were also carrying out with the equally unreliable QX949. This unit had been purchased by someone in the Republic of Ireland who regularly brought it over to Iver Heath in England, at his own expense.

Pioneer were so embarrassed by these failings that they put a car on for the customer to and from the London Heathrow Airport just for his trouble!

These products were meant to be premium items and bad publicity could have been very damaging to the company. I could not fault the service that they gave me. Just a pity that Pioneer in Japan chose to use poor quality components in the first place.

In all external appearance it was a very attractive piece of hi-fi equipment and if you enjoy it then I hope that you continue to do so.

Just remember that SQ decoders including the Pioneer QD210 do not work well with an amplifier or receiver that already incorporates a matrix device!

Best Wishes to you.

David

 

[mgmuscari]

The Sony decoders, (mine were SQD2020 and SQD2010 and still are), they did not work as intended through the QX8000 or any other receiver I have tried.

Currently this is two Sansui QRX9001's and the same goes for the Sansui QSD2 if used with a receiver.

These SQ or in the case of Sansui QS decoders were intended to be add on units to an existing stereo system in the early to mid 1970's.

If your Sony SQ decoder is used with two separate stereo amplifiers as intended in the instruction manuals supplied (at least here in England) then all is well.

Electrical engineer here. I just spent my whole weekend working through the power supply of my SQD-2020 tracking down a bad zener diode that was causing one of the voltage rails going to the B board to go way too high, screwing with the logic operation. I had to do some very careful tracing back from the front-back logic and AGC sections to figure this out. These circuits share common ground. The output buffer amplifiers also share the same ground. There is absolutely zero electrical difference between the grounds on the outputs. You can probe the grounds of both the front out and rear out RCA connectors if you don't believe me, and you will find 0 ohms impedance. There is no consequence to hooking this unit up to a 4-channel receiver or amplifier. I have mine feeding a Pioneer QC-800a preamp on a tape loop so that I can select which quad decoder to use with the tape monitor switch. That feeds a Pioneer QM-800a 4ch amplifier. Whatever you heard from that service engineer is just superstition.

In software engineering we call this mindset "cargo cult programming." An engineer who doesn't exactly understand the principles of operation of a particular component will ritualistically preserve some bit of code across many programs without understanding its intended or actual effects, just knowing that it was there at some point for some reason. This often means that the piece of code in question serves absolutely no function in the program in question, or even worse, causes some kind of deleterious effects.

SQD-2020 owners, fear not, you can feed your 4-channel receiver, preamp, or amplifier directly from your SQD-2020. Use the 'low' output for the rear channels as that's line level. The 'high' output is very hot and will likely cause clipping in most components you'd try to feed from it. In case you're wondering, the difference between the 'low' and 'high' outputs is electronically trivial. The 'low' output is implemented as a leg in a simple voltage divider - each rear channel has a pair of resistors feeding the 'low' circuit off the 'high' one.

One important thing to do to get the best signal out of these units - observe the unity gain principle. Use the input level pot on the back to adjust whatever 2-ch signal you're feeding in to a reasonable level. You should not see the output level meters pass +3dB when you have the master volume and channel trim pots turned to max. This will avoid clipping & distortion within the SQD-2020 and ensure that you're getting a nice clean signal back into your preamp. I balanced my unit with the master volume set to max gain, and the channel pots at 12 o'clock, adjusting the input level sensitivity until engaging the tape monitor switch on my preamp to cut in the SQD-2020 made no difference in the level being fed to the power amp.

 

[Pontoneer]

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 .