SQ: Sony SQD-2020 SQ Decoder

[Q8]

I find that the HR-99 and HR-100 really knocks my socks off for regular 8-Track playback. And some people say that the dolby NR in the HR-100 is pointless, I don't think that. I can definately tell the difference. Too bad that Pioneer didn't actually make a 4-channel recording 8-Track deck. The pioneer motors can drag just about any tape through smoothly. Also, I can't help but feel that the QH-44 is the cutest Q8 deck ever made, lol

 

[Q8]

Also StarTrek1701 sent me the SQD-2020 owners manual so PM me your email address if you need it.

 

[Hank]

There is a 2020 on ebay right now.

 

[surteess]

I have SQD-2000, 2010 & 2020 - they are all good little units (when correctly calibrated).

The main differences are -

SQD-2000 - total discrete components mounted on 2 A4 size single-sided pcbs (mounted one above the other)

SQD-2010 - custom ICs mounted on 1 A4 single-sided pcb

SQD-2020 - total discrete components mounted on 1 A4 double-sided pcb (riveted to join tracks from one side to the other - when unit is faulty resolder both sides of ALL rivets that normally fixes the issue).


SQD-2010 is in my opinion the best option (provided it is setup - leave the internal pots alone!!) it must have also been the most expensive to design, using the custom ICs - I have yet to find any information on the ICs. This unit does not normally "pump" like the other discrete units.

I have service manuals for all 3 + about 40 other quad manuals from Sony/JVC/Technics etc

The only things I am still searching for is a copy of service/owners manual for my Sony SQE-2000 (SQ encoder) & ST-5555 (Tuner)

Here is my setup - I also have a very understanding lady also living in the house!!! (and a Griffon dog who loves music & does not chew any cables)

System 1 – mix of Sony & JVC & Toshiba & Eversonic

VT-700 (Tuner)
SEA-V7E (Equalizer)
SQD-2000 (Decoder)
4VN-880 (Amp)
KD-10 (Cassette)
HR-40 (4-Channel Headphones)
Eversonic (4 off) 50W 5-way


System 2 – mix of Sony & JVC & Philips

VT-700 (Tuner)
SEA-V7E (Equalizer) - front
SQD-2010 (Decoder)
SEA-V7E (Equalizer) - rear
4VN-880 (Amp)
5911 (4-Channel Remote)
5944 (4-Channel Headphones)
733K (CD)


System 3 – Sony & Technics & Magnat

ST-5150 (Tuner)
TA-1150 (Amp) – front
SQD-2020 (Decoder)
TA-1150 (Amp) – rear
D-5A (CD)
EAH-400 (4-Channel Headphones)
Magnat-6 Speakers (4 off) 160W 3-way

System 4 – PC system, to transfer SQ/QS LPs to CD

PC with sound blaster Live 5.1
Sound Forge software
Sound Laundry software
SL-10 (Turntable)
Terratec Phono Pre-Amp Studio


I also have the following other pieces in my collection.

Cosrad HS 4000 4-Channel Headphones
Hafler 101A Preamp
KD-10 Cassette – used for spare parts
JVC ECA-102 4-Channel Reverb.
Marantz ST-400 Tuner (modified by myself to include AM Stereo PCB)
Pioneer QD-240 CD-4 Demodulator
Quad 405mkII Amp (home made copy - nice Chrome case that changes colour when hot!!)
Sony SQA-100 Decoder (3)
Sony SQA-200 Decoder
Sony SQA-2030 Decoder
Sony SQD-1000 Decoder (2)
Sony SQD-2020 Decoder
Sony SQD-2050 Decoder (2)
Sony SQD-2070 Decoder
Sony SQE-2000 Encoder
Sony ST-80F Tuner (3)
Sony ST-88 Tuner (2)
Sony ST-2950 Tuner
Sony ST-5555 Tuner
Sony TA-88 Amp (3)
Sony TA-1055 Amp (3)
Sony TAH-10 Headphone adapter
Technics SH-400 CD-4 Demodulator
Technics SH-3433 Scope

Plus Service manuals for most of the above.

Plus approx 500 Quad LPs & about 50 Quad cds

*Don't forget that most 70s Japanese gear is equipped already with world transformers - check out the little raised rectangle on the back of the sony used in original photo - "CAUTION - DO NOT REMOVE SCREWS" go on unscrew it, hey presto world selector, really good if you want to buy on ebay & trasnport to 220-240V countries* like I do.

 

[cupboy]

Only Akai & Panasonic offered Q8 recorders that recorded in Quad. All other Q8 recorders play back in Quad, but only record in stereo! Ridiculous.

Manufacturing a record head for 4-channel recording that avoided crosstalk was probably was too expensive at the time.

 

[Q8]

So I have a couple questions about the case options for the 2020. I know there was an optional wood case. Were there different finishes? Does anyone have good pics?

Also there was another case option. Even more rare. The Acryl case. Is that some sort of plastic case? Is it like clear acrylic? Does anyone know about those or have pictures?

 

[Quad Linda]

As I recall, the wood case was a lot of $$$, perhaps $100 new. I'm not aware of an acrylic case being sold to consumers. Many pieces of hi-fi have had promotional acrylic cases given to dealers to show the gear's innards. I suspect that the acrylic case you're mentioning was either one of those, or manufactured as aftermarket.

Many Sony models of the time did come with wood cases. My 2 ch Sony STR-7065A came standard with a wood case.

So I have a couple questions about the case options for the 2020. I know there was an optional wood case. Were there different finishes? Does anyone have good pics?

Also there was another case option. Even more rare. The Acryl case. Is that some sort of plastic case? Is it like clear acrylic? Does anyone know about those or have pictures?

 

[Q8]

I did it! I just received in the mail, two, count em' two! New old stock in the box Sony Wood Cases for the SQD-2020 and other sony seperates. One only missing the hardware (4 screws), the other complete with the hardware. I will help cure Sony decoder baldness now. Lol. One of these will really jazz up the 2020. The other, not sure yet, probably will hold on to it in case I get a 2010 or one of those other Sony quad preamps. If I were to trade it, it would have to be for one hell of a quad trade (just sayin', if someone PM's for it, it had better be a cool trade for me to consider, lol).

 

[soundcentre]

I derived a lot of pleasure from reading this post, but be aware that these Sony decoders were intended to transform your 1970's stereo system to 4 channel SQ. They were not however intended to be connected to a one box four channel amplifier or receiver, with a common earth!

Such a connection will likely cause breakdown of the output transistors to the SQD2020 and worse still, failure of the chip set in the SQD2010 in the long term.

Careful study of the instruction manuals, (for those who have them), even more careful to those with service manuals will confirm the above.

This is why the decoders have two different line level outputs to rear amplifiers and tone controls for rear, (bass and treble), only. They are intended for use only with separate rear channel amplifiers. In the 1970's the Sony 3140F with screw driver adjustable line level controls was recommended), as the rear power amplifier.

Back in the 1980's I was informed by a senior technician at Sony UK, (then located at Sunbury on Thames), that the company had repaired many units where the suspected connection as illustated in the accompanying manual, had not been followed.

At that time I was seeking the SQD2010 of which I now have two. I was told to make sure that they work before second hand purchase, as no replacement chips were available circa 1986/7!

As a matter of interest a basic SQ encoder is shown in the service sheets for resetting the many variable circuit board mounted capacitors in an SQD2020. This easy to make up device is used to inject at the appropriate points a 1kHz tone, generated by a standard audio generator connected to it.

I have been known in the past to replace output transistors when these failed and found them not too particular to correct decoding after recaliberation. This even though exact replacements became difficult to source.

The best recommendation is to leave well alone, do not connect to a common earth 4 channel amplifier, follow Sony's instructions to the letter and enjoy.

This advice comes after only forty years of wielding a soldering iron and an amazing lack of that dreadful pumping effect so beloved of people who do not like instructions!

Best wishes.

David

 

[Q8]

I derived a lot of pleasure from reading this post, but be aware that these Sony decoders were intended to transform your 1970's stereo system to 4 channel SQ. They were not however intended to be connected to a one box four channel amplifier or receiver, with a common earth!

Such a connection will likely cause breakdown of the output transistors to the SQD2020 and worse still, failure of the chip set in the SQD2010 in the long term.

Careful study of the instruction manuals, (for those who have them), even more careful to those with service manuals will confirm the above.

This is why the decoders have two different line level outputs to rear amplifiers and tone controls for rear, (bass and treble), only. They are intended for use only with separate rear channel amplifiers. In the 1970's the Sony 3140F with screw driver adjustable line level controls was recommended), as the rear power amplifier.

Back in the 1980's I was informed by a senior technician at Sony UK, (then located at Sunbury on Thames), that the company had repaired many units where the suspected connection as illustated in the accompanying manual, had not been followed.

At that time I was seeking the SQD2010 of which I now have two. I was told to make sure that they work before second hand purchase, as no replacement chips were available circa 1986/7!

As a matter of interest a basic SQ encoder is shown in the service sheets for resetting the many variable circuit board mounted capacitors in an SQD2020. This easy to make up device is used to inject at the appropriate points a 1kHz tone, generated by a standard audio generator connected to it.

I have been known in the past to replace output transistors when these failed and found them not too particular to correct decoding after recaliberation. This even though exact replacements became difficult to source.

The best recommendation is to leave well alone, do not connect to a common earth 4 channel amplifier, follow Sony's instructions to the letter and enjoy.

This advice comes after only forty years of wielding a soldering iron and an amazing lack of that dreadful pumping effect so beloved of people who do not like instructions!

Best wishes.

David

Interesting. It seems that like me, most people, especially nowadays use this incorrectly. I would also bet that Sony reps sold them at the time as an add-on upgrade to the poor decoders in the receivers people already had. Or to add SQ to a QS only receiver. I would imagine that people also connected these to the other Sony quad preamps.

Would connecting the 2020 to two stereo preamps prior to the 4-channel amp or receiver alleviate this risk?

Also it seems that many QQ members have been running these the incorrect way for a great number of years without serious issue. Not sure if I should be worried or not.

 

[soundcentre]

Interesting. It seems that like me, most people, especially nowadays use this incorrectly. I would also bet that Sony reps sold them at the time as an add-on upgrade to the poor decoders in the receivers people already had. Or to add SQ to a QS only receiver. I would imagine that people also connected these to the other Sony quad preamps.

Would connecting the 2020 to two stereo preamps prior to the 4-channel amp or receiver alleviate this risk?

Also it seems that many QQ members have been running these the incorrect way for a great number of years without serious issue. Not sure if I should be worried or not.

Your question above is answered by the word YES!

Many dealers were keen to shift these units from their shelves, exactly as you indicate and with the result that I quoted from a Sony engineer above. If you have used a Sony SQD2010 or SQD2020 without incidence and do not suffer the pumping effect at all, then no worries. You have had much more luck than me since taking up SQ in 1973!

Best wishes.

David

 

[quadsearcher]

I only mention this because I was thinking of getting one. I got the schematic when I was looking into SQ. The grounds for front and back are clearly connected to each other and the center tap of the mains transformer as they should be. If back needed to have a separate floating ground from the front there would need to be a second power supply. There is only one power supply circuit and one common ground.

Now, if there was a production change not covered by this schematic then anything is possible. Measuring resistance between front ground and back ground at the RCA connectors should show zero or very close to it, and this would be evidence that the schematic is correct. If someone has an ohmmeter and a 2020, please check this for me, if the units do not follow the published schematic I'll cross the 2020 off my want list!

 

[soundcentre]

I only mention this because I was thinking of getting one. I got the schematic when I was looking into SQ. The grounds for front and back are clearly connected to each other and the center tap of the mains transformer as they should be. If back needed to have a separate floating ground from the front there would need to be a second power supply. There is only one power supply circuit and one common ground.

Now, if there was a production change not covered by this schematic then anything is possible. Measuring resistance between front ground and back ground at the RCA connectors should show zero or very close to it, and this would be evidence that the schematic is correct. If someone has an ohmmeter and a 2020, please check this for me, if the units do not follow the published schematic I'll cross the 2020 off my want list!

The issue lies with the equipment that the matrix decoder has to work into. For example you would never expect to connect a pair of four channel headphones to any such arrangement as a Sony SQD2010 or SQD2020. Unless that is you want to hear the decoder working. That is to say, to listen without the masking which the decoder provides only to loudspeaker usage. These units were specifically designed to convert your existing stereo to quadraphonic and encompass level and rear tone circuits, because the manufacturer correctly guessed that many would be purchasers, did not have matching front and back loudspeakers.

Although capable of working with middle of the road hi fi of 1970's origin, these decodes really fly today with the best quality inputs, both in terms of cartridge, turntable and especially RIAA amplifier.

They should sound quite open and almost ethereal in operation, clearly enabling the listener to detect the different types of mixing used in the original recording down to CBS SQ standard. Of the two, the later SQD2010 with its very fast and silent acting logic is the superior. This is not to say that forty years ago an SQD2020 could not pass muster, but all these years later with 69 transistors and 84 diodes and a double sided printed circuit board, likely since to have at least one dry joint out of hundreds, the IC Built generation seem to last longer.

I have had years of satisfaction from them, I hope you discover a working unit of your choice and enjoy it.

Best wishes.

David

 

[Q8]

I'm not trying to be rude here, but your answer seems to be to a completely different question.

The subject was that the design of the 2020 and 2010 was such that connecting them directly to a 4 channel receiver or amp would cause physical damage to them.

Also even though quad headphones don't work well, that is my only complaint about the 2020/2010 as a preamp. It would have been nice to have headphone ports.

 

[soundcentre]

I'm not trying to be rude here, but your answer seems to be to a completely different question.

The subject was that the design of the 2020 and 2010 was such that connecting them directly to a 4 channel receiver or amp would cause physical damage to them.

Also even though quad headphones don't work well, that is my only complaint about the 2020/2010 as a preamp. It would have been nice to have headphone ports.

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.

 

[Q8]

I'm not aware of an acrylic case being sold to consumers. Many pieces of hi-fi have had promotional acrylic cases given to dealers to show the gear's innards. I suspect that the acrylic case you're mentioning was either one of those, or manufactured as aftermarket.

Woo hoo, I actually found a German Sony catalog page selling the HA-40 acrylic case that fits the SQD-2020. That doesn't prove that they actually made or sold any, but I would imagine that there are at least a handful out there. Talk about a collectors item!

http://audioidiots.com/merk.catalogus.scanned.groot.php?catalogusID=83&pagina=006&merkID=

Also on that page is the TAC-1N like I just got.

Cool stuff. I wish I could get my hands on some US or UK quad-era Sony catalogs. Or any country in English.

Did the Japanese catalogs just print in Japanese or did they do the dual Japanese/English thing?

 

[Owen Smith]

I just love those early 1970s Sony designs with the beautiful knurled silver knobs and the wooden cases. My dad had a Sony stereo Receiver like that which did service until the late 1980s. Alas it developed multiple faults and was ditched, I have neither the model number nor a photo. The mains switch had such a satisfying action to it as you swung it up. Happy memories, I recorded Queen at Live Aid using it plus a Sony top loading 3 head cassette deck of similar vintage.

Sorry to derail your thread, but the pictures of that early 1970s SQD-2020 brought back memories. Those knobs, sigh.

 

[Quad Linda]

I had an STR-7065A in the 70's, replete with wood case. My cousin has had it now for 30 years. I still have my SQuid-2020.

 

[Owen Smith]

I had an STR-7065A in the 70's, replete with wood case. My cousin has had it now for 30 years. I still have my SQuid-2020.
View attachment 11031

That's not the same as my dad's receiver but is very similar. The mains switch bottom left clearly is the same. I loved that mains switch so much when I was younger I got told off for just turning it on and off repeatedly.

 

[Q8]

What started me down this rabbit hole of quad was finding a SQR-4750 at a yard sale




Those pics aren't mine. Just found a couple pics on the net. Coincidentally and unfortunately, one of the channel level knobs stem was broken off mine as well. The pot still works. Trying to figure out if there is a way to fix that without replacing the whole pot. It's a cool receiver though.

I also have a Sony SQD-2020, a Sony Q8 deck and a Sony Quad reel deck.