Electronics Today International ETI Australia. Issues from the 70's.

[Gabriel Santos]

I'm researching on diy SQ decoders and there were a issue of the ETI australia presenting the project bellow. I'm not sure which issue it was, but it is, for sure, something during the 70's, so, does anyone know what issue was it published or have such issue? It was taken from http://art-and-technology.blogspot.com/2015/12/sq-quadraphonic-dead-surround-audio.html

 

[Sonik Wiz]

I'm researching on diy SQ decoders and there were a issue of the ETI australia presenting the project bellow. I'm not sure which issue it was, but it is, for sure, something during the 70's, so, does anyone know what issue was it published or have such issue? It was taken from http://art-and-technology.blogspot.com/2015/12/sq-quadraphonic-dead-surround-audio.html
View attachment 39951

On the American Radio History website I get multiple search hits for ETI Au Project 420 but then the link goes dead:

ETI Australia

Maybe you will have better luck. At any rate the ARH website is a treasure trove for researching all things quad.

I have to laugh at the description "discrete SQ decoder". This is obviously just a basic SQ decoder with 10/40 blend on the output channels.

 

[Clint Eastwood]

I'm researching on diy SQ decoders and there were a issue of the ETI australia presenting the project bellow. I'm not sure which issue it was, but it is, for sure, something during the 70's, so, does anyone know what issue was it published or have such issue? It was taken from http://art-and-technology.blogspot.com/2015/12/sq-quadraphonic-dead-surround-audio.html
View attachment 39951

Welcome to the forum

 

[Gabriel Santos]

On the American Radio History website I get multiple search hits for ETI Au Project 420 but then the link goes dead:

ETI Australia

Maybe you will have better luck. At any rate the ARH website is a treasure trove for researching all things quad.

I have to laugh at the description "discrete SQ decoder". This is obviously just a basic SQ decoder with 10/40 blend on the output channels.

I've already looked up on ARH with no succes, they have some australian issues, but none of them have such project, the worse thing is that I don't even know which issue to look for, I'm guessing something between 72-75. And yes, it is just a wide frequency range shifter with the basic 10/40 blend, but I think I've seen a transistor based logic circuitry, thus discrete, in some sony decoder. All the research I'm doing is part of my electric engineering final paper on which I'm doing an analysis of this ETI circuit and also part of a bigger project. The final paper is gonna be a transfer function analysis of some relevant points of the shifter, which is almost done and took a huge effort to understand the transistor RC collector-to-emitter network. After that, once the final paper is presented to all the proffessors and I get my degree, I want to redesign the circuit into tubes, study the logic circuitry and, if possible, disign a tube based one.

 

[Soundfield]

I got the same 'unavailable' message on the American Radio History website as you SW. I discovered that the circuit was also published in the UK edition in June 1974 - but that that one is not there either (or anywhere else I could find).

Not sure what you really wanted the article for Gabriel, other than giving a printed board layout and a parts list it won't tell you much more than the circuit diagram shows you. As you realise, its as basic a decoder as you can get and has very little separation largely as a result of having such a feeble phase shift network. It was using a circuit like that in its earliest decoder (the SQD-1000) that Sony nearly managed to strangle the format at birth as its performance was so poor!

But, to be fair to ETI, I don't think ETI were making any claims for discrete 4ch system levels of performance but were rather just indicating it was made with discrete components rather than ICs (the Motorola set having been announced about that time).

 

[Gabriel Santos]

I got the same 'unavailable' message on the American Radio History website as you SW. I discovered that the circuit was also published in the UK edition in June 1974 - but that that one is not there either (or anywhere else I could find).

Not sure what you really wanted the article for Gabriel, other than giving a printed board layout and a parts list it won't tell you much more than the circuit diagram shows you. As you realise, its as basic a decoder as you can get and has very little separation largely as a result of having such a feeble phase shift network. It was using a circuit like that in its earliest decoder (the SQD-1000) that Sony nearly managed to strangle the format at birth as its performance was so poor!

But, to be fair to ETI, I don't think ETI were making any claims for discrete 4ch system levels of performance but were rather just indicating it was made with discrete components rather than ICs (the Motorola set having been announced about that time).

What should a expect? 90degrees+-10 from 100Hz-10KHz? Which is almost what the Motorola IC does.

 

[Gabriel Santos]

Do you guys think australian libraries have back issues scanned or even the paper versions? Or in the case of the UK edition, some library in London or elsewhere would have it?

 

[Sonik Wiz]

What should a expect? 90degrees+-10 from 100Hz-10KHz? Which is almost what the Motorola IC does.

Wow
You just made me realize if it's not in my collection or on line I've totally lost my savvy how to look elsewhere.

I would suggest taking a look at fellow member chucky3042 & perhaps drop him a message. He is in Australia, a surround sound fanatic & major partner with Involve Audio. If he's like me, he just might be in possession of the info you need.

Indeed welcome to the forum! Best of luck on your education & career. Stick around it's a great place to be.

 

[Gabriel Santos]

Wow
You just made me realize if it's not in my collection or on line I've totally lost my savvy how to look elsewhere.

I would suggest taking a look at fellow member chucky3042 & perhaps drop him a message. He is in Australia, a surround sound fanatic & major partner with Involve Audio. If he's like me, he just might be in possession of the info you need.

Indeed welcome to the forum! Best of luck on your education & career. Stick around it's a great place to be.

Thank you, will talk to him. And, as soon as I finish I'll translate the whole paper into english and post it somewhere. By the way, the transfer function of the RC collector-to-emitter network was obtained through a mesh analysis of the T model.

 

[DuncanS]

Do you guys think australian libraries have back issues scanned or even the paper versions? Or in the case of the UK edition, some library in London or elsewhere would have it?

I used to get papers for my research from the British Library via my University Library. The British Library has all UK published magazines etc. So if you can find out the year, issue, and which pages from ETI you require, you might be able to get your University to request it from the British Library. They do charge for the service. Sadly my parents threw out all my Electronics Magazines from 1969-79 otherwise I'd have it
Note: I do have all the Wireless World from 1975 onwards, until it became a joke of a magazine in the 90s.

 

[Gabriel Santos]

I used to get papers for my research from the British Library via my University Library. The British Library has all UK published magazines etc. So if you can find out the year, issue, and which pages from ETI you require, you might be able to get your University to request it from the British Library. They do charge for the service. Sadly my parents threw out all my Electronics Magazines from 1969-79 otherwise I'd have it
Note: I do have all the Wireless World from 1975 onwards, until it became a joke of a magazine in the 90s.

Good to know, but as Soundfield pointed out, I shouldn't expect to get more than the circuit diagram and parts list, which I don't think is worth paying whatever they charge. And about the wireless world, I also found a simpler circuit on a 70's issue available on AMH, so, thank you anyway.

 

[Gabriel Santos]

It also got to my knowledge that the AES has many articles published on there journals. What should I expect of such articles? Some technical coments of the phase shifting and/or some engineering level analysis?

 

[Sonik Wiz]

It also got to my knowledge that the AES has many articles published on there journals. What should I expect of such articles? Some technical coments of the phase shifting and/or some engineering level analysis?

Not replying about AES but some good information about phase shifts is here.

 

[Soundfield]

Tricky things broadband phase shifters- its all about the poles!

 

[Gabriel Santos]

Thank for all those who took their time in replying. I'm almost done with the calculations and soon I'll start the building of the circuit process, and I've been waiting to finally give a SQ Dark Side of the Moon a chance to being played in 4 channels for so long, yet I know it won't be a big time thing due to the lack of logic and the smplicity of the circuit. For what it's worth, does anyone know how different a well decoded, with logic, SQ version of the Darkside is from the quad 8 track counterpart?

 

[Gabriel Santos]

Note, I don't own the tape nor the tape deck, not just yet.

 

[Circular Vibes]

If you go for the 8track, get the UK version. The US version pictured is poorly decoded from the SQ, not discrete like the UK tape. This mix is also on BluRay but as part of an expensive set. The quad tape is expensive too so that has to be a comsideration. I have the SQ LP from the UK and it has been the most played (and worn) quad LP in my collection. Time to look for a new copy. My last one was free as the customer in the record store I worked in returned it claiming wear and sibilance. Guess my ears weren't so golden but I still played it a lot.

 

[Gabriel Santos]

This is what I got, a brazilian version of the SQ, any coments on such version?
View attachment 39972

 

[Gabriel Santos]

If you go for the 8track, get the UK version. The US version pictured is poorly decoded from the SQ, not discrete like the UK tape. This mix is also on BluRay but as part of an expensive set. The quad tape is expensive too so that has to be a comsideration. I have the SQ LP from the UK and it has been the most played (and worn) quad LP in my collection. Time to look for a new copy. My last one was free as the customer in the record store I worked in returned it claiming wear and sibilance. Guess my ears weren't so golden but I still played it a lot.

This is what I got, a brazilian version of the SQ, any coments on such version?