Technics SA-8500x

[gvl_guy]

I'm pretty sure on here I saw that someone integrated an Involve Surround Master into the 8500x. That would make it nearly the perfect "vintage" quadraphonic receiver!

 

[par4ken]

While I have always rejected the argument that multiple systems killed quad, the actions of some of the players was not at all helpful.

Until looking at the Technics manuals I didn't realize just how little thought was given to matrix by Technics/Panasonic. They obviously didn't want to include circuitry that would in any way compete with the discrete format that they were championing!

In complete contrast Sansui while championing QS, included CD-4 in some models and even made a stand alone demodulator. The QRX receiver models also decoded SQ reasonably well. Had all the manufactures acted more like Sansui and less like Technics the format "war" need not have happened!

 

[MidiMagic]

Panasonic called its matrix decoder "Quadruplex". It seems to be an RM or QM decoder.

 

[DudeRocks]

I must agree with you & @kfbkfb. The matrix decoding is simple with no logic assist of any kind. The documentation for the CD-4 is pretty good but not even a schematic for the matrix decoder section, just a PCB parts lay out. However even from this I can tell that neither of the matrix decode modes are for SQ. There's only 4 transistors for the whole matrix PCB & you can't do SQ with that. You need multiple phase shift elements that has a certain repeating parts layout that makes it easy to tell they are 90 deg phase shifters as needed for SQ.

So one of the decode positions probably matches RM and one will have different blend coefficients that might be closer to EV-4. Still, no SQ, no logic.

Actually it sounds pretty good. I did my favorite test. Janis Joplin Pearl the Mercedes-Benz song. I have other albums for testing SQ but so far this is my favorite test as it's simple, there's a part where she says everybody now and her voice specifically goes over all 4 and is turned up to the rear channel. Even Dolby enabled modern receivers can handle that. So if we're talking about the Technics "crappy, basic, only 4 transistors, no logic" being able to pull off SQ then I'm not sure why bother modding it with a 700 dollar Surround Master. Here comes the fan boys. Lol.

 

[MidiMagic]

Actually, any RM decoder can play SQ, but it is a little different:

F and B are the same in both matrix systems.

SQ LF and RF are wider than in SQ, often at the L and R sides.

SQ LB and RB are at equal levels in all speakers..

 

[quadsearcher]

Actually it sounds pretty good. I did my favorite test. Janis Joplin Pearl the Mercedes-Benz song. I have other albums for testing SQ but so far this is my favorite test as it's simple, there's a part where she says everybody now and her voice specifically goes over all 4 and is turned up to the rear channel. Even Dolby enabled modern receivers can handle that. So if we're talking about the Technics "crappy, basic, only 4 transistors, no logic" being able to pull off SQ then I'm not sure why bother modding it with a 700 dollar Surround Master. Here comes the fan

I don't understand. Are you testing performance of a decoder by how well a sound mixed to all speakers comes out of all speakers? "her voice specifically goes over all 4"?

A poor decoder would perform as well as any decoder if using only that for comparison. (Or am I wrong here? Are there any decoders intended for the format being played that can't reproduce a signal assigned to all channels correctly in all channels?). Might as well have four mono channels, just turn up the back and voila! The opposite of a separation test, no?
Specs don't necessarily matter though, regarding music. What matters is if you like it. If it works, it works!

 

[DudeRocks]

I don't understand. Are you testing performance of a decoder by how well a sound mixed to all speakers comes out of all speakers? "her voice specifically goes over all 4"?

A poor decoder would perform as well as any decoder if using only that for comparison. (Or am I wrong here? Are there any decoders intended for the format being played that can't reproduce a signal assigned to all channels correctly in all channels?). Might as well have four mono channels, just turn up the back and voila! The opposite of a separation test, no?
Specs don't necessarily matter though, regarding music. What matters is if you like it. If it works, it works!

No, I think you missed the point. I'm actually in agreement with your comment and pointing out based on that comment the surround Master and Dolby is no better than RM in this regard. You are right if it works it works. I keep seeing fanboys saying the opposite of that because they read the specs were not full logic or only half logic so they must be "bad".

The test itself using that particular album you would hear music from the rear but specifically NOT her voice. You also missed here "I have other albums for testing SQ" and they also work very well on this, I recommend you try Santana abraxas and the introduction to the world of SQ. It's just easier/simpler to explain that the Pearl album is easier to identify when the SQ is working correctly. It's more exact to the moment and can hear if it's clearly working or not.

 

[quadsearcher]

No, I think you missed the point. I'm actually in agreement with your comment and pointing out based on that comment the surround Master and Dolby is no better than RM in this regard. You are right if it works it works. I keep seeing fanboys saying the opposite of that because they read the specs were not full logic or only half logic so they must be "bad".

The test itself using that particular album you would hear music from the rear but specifically NOT her voice. You also missed here "I have other albums for testing SQ" and they also work very well on this, I recommend you try Santana abraxas and the introduction to the world of SQ. It's just easier/simpler to explain that the Pearl album is easier to identify when the SQ is working correctly. It's more exact to the moment and can hear if it's clearly working or not.

"voice specifically goes over all 4 and is turned up to the rear channel." or "music from the rear but specifically NOT her voice"

I'm still confused, but no matter. It might be clearer to me if I pulled out the record, it has been a while. One of these days.

I do believe that most or all fans of surround here sincerely want to help other fans of surround in the hobby, and part of this is helping to find hardware that best plays back the content as it was intended.
Or not intended as the case of stereo to surround.
I hear Tate made a good decoder. But Hafler can be fun too.

Pearl would be a great choice for a digital reissue, I would think It'd be a big seller, BD or SACD..

Rock on!

 

[DudeRocks]

"voice specifically goes over all 4 and is turned up to the rear channel." or "music from the rear but specifically NOT her voice"

I'm still confused, but no matter. It might be clearer to me if I pulled out the record, it has been a while. One of these days.

I do believe that most or all fans of surround here sincerely want to help other fans of surround in the hobby, and part of this is helping to find hardware that best plays back the content as it was intended.
Or not intended as the case of stereo to surround.
I hear Tate made a good decoder. But Hafler can be fun too.

Pearl would be a great choice for a digital reissue, I would think It'd be a big seller, BD or SACD..

Rock on!

The Tate, the surround master, sansui 9001 and the 949A, I have not had a chance to hear and I'm not going to let my curiosity get to my wallet unless I stumble upon one of these things at an estate sale. I'll take your word for it! I went the route of the sleeper quad, Laphayette. Starting with a LA64 and a LR5000 and two LR3000s. Recently picked up a technics SA8500X where the quadraphonic works on it but the amps are going to need a recap.

From what I'm noticing, everything I've had hooked up to a vintage quad receiver or amplifier when playing stereo, You can choose stereo but if you have four channel on, it'll duplicate the front left right to the rear left right. I have actually had one of these that was not working where the SQ and CD4 etc just duplicated stereo no matter what. Janis Joplin helped me figure that out! Lol

 

[par4ken]

The Tate, the surround master, sansui 9001 and the 949A, I have not had a chance to hear and I'm not going to let my curiosity get to my wallet unless I stumble upon one of these things at an estate sale. I'll take your word for it! I went the route of the sleeper quad, Laphayette. Starting with a LA64 and a LR5000 and two LR3000s. Recently picked up a technics SA8500X where the quadraphonic works on it but the amps are going to need a recap.

From what I'm noticing, everything I've had hooked up to a vintage quad receiver or amplifier when playing stereo, You can choose stereo but if you have four channel on, it'll duplicate the front left right to the rear left right. I have actually had one of these that was not working where the SQ and CD4 etc just duplicated stereo no matter what. Janis Joplin helped me figure that out! Lol

It is normal for CD-4 to output as double stereo when playing a stereo record. The same if for some reason it is not picking up the CD-4 carrier. The same thing goes with most Q8 decks, they play double stereo, with a stereo tape inserted. Sometimes you can switch to just the front speakers, but why? Even double stereo IMHO is an enhancement over regular stereo.

Vintage decoders can vary greatly in just how effective they are. Any SQ decoder should do more than double stereo. For years I used the original Audionics decoder. It included no logic circuitry. Playing stereo you got stereo from the front, you also got sound from the back equal in level to the front but just a phase shifted combination of the original stereo pair. The effect was very pleasing even if not what you would call discrete. In the case of an SQ record played through that SQ decoder the intended directionality could be clearly heard if you sat in the middle of the speakers. The spaces between speakers was seemingly filled with a mix of the phase shifted cross talk components. While some people found the sound unimpressive I always thought that it sounded great. Playing QS through the same SQ decoder sounded fantastic as well. While the directional effects weren't always correct the resulting surround sound was very pleasing.

Comparing the RM decoder of the Sony SQD-2010 to the Involve Evaluation module I was struck by just how similar they sounded. The Involve shined by removing almost all the centre front vocal from the rear, while the Sony RM decoder had a fair bit of front leakage to the rear. In practice there was still enough front to back separation to focus the vocals to the front using the Sony. No logic circuitry is used by the Sony in the RM mode. The full logic SQ circuitry of the Sony is not suited well to stereo synthesis as it reduces the rear speaker levels too much.

QS Vario-matrix and especially Tate decoders can separate the channels in a very discrete like manor. This produces a much different surround experience than that of the more basic decoders. They do impress most listeners. In the case of QS surround mode and the Tate II Surround mode and S&IC Stereo Enhance mode, the stereo is pulled apart, stretched between the four speakers.

 

[DudeRocks]

It is normal for CD-4 to output as double stereo when playing a stereo record. The same if for some reason it is not picking up the CD-4 carrier. The same thing goes with most Q8 decks, they play double stereo, with a stereo tape inserted. Sometimes you can switch to just the front speakers, but why? Even double stereo IMHO is an enhancement over regular stereo.

Vintage decoders can vary greatly in just how effective they are. Any SQ decoder should do more than double stereo. For years I used the original Audionics decoder. It included no logic circuitry. Playing stereo you got stereo from the front, you also got sound from the back equal in level to the front but just a phase shifted combination of the original stereo pair. The effect was very pleasing even if not what you would call discrete. In the case of an SQ record played through that SQ decoder the intended directionality could be clearly heard if you sat in the middle of the speakers. The spaces between speakers was seemingly filled with a mix of the phase shifted cross talk components. While some people found the sound unimpressive I always thought that it sounded great. Playing QS through the same SQ decoder sounded fantastic as well. While the directional effects weren't always correct the resulting surround sound was very pleasing.

Comparing the RM decoder of the Sony SQD-2010 to the Involve Evaluation module I was struck by just how similar they sounded. The Involve shined by removing almost all the centre front vocal from the rear, while the Sony RM decoder had a fair bit of front leakage to the rear. In practice there was still enough front to back separation to focus the vocals to the front using the Sony. No logic circuitry is used by the Sony in the RM mode. The full logic SQ circuitry of the Sony is not suited well to stereo synthesis as it reduces the rear speaker levels too much.

QS Vario-matrix and especially Tate decoders can separate the channels in a very discrete like manor. This produces a much different surround experience than that of the more basic decoders. They do impress most listeners. In the case of QS surround mode and the Tate II Surround mode and S&IC Stereo Enhance mode, the stereo is pulled apart, stretched between the four speakers.

Don't forget the Lafayette "Full wave matching" SQ sounds pretty awesome as well. ACDC's back in Black, it doesn't matter if it's vinyl, CD, or on the radio his vocals are up front with guitars all around. Also Hotel California came over FM one day and the vocals were also kept to the front speakers the whole song. Even the rap rnb station was doing it. It's pretty cool to see how this works with modern music.

What I'm mostly looking forward to with the SA-8500X is the strain gauge support. I accidentally bought a SL-701 CD4 turntable that only supports SC, you can't turn it off to use another cart for the CD4! So I picked up two NOS EPC-451c and 450c in a bundle and am looking to try one of them in a modern TT running to the CD4 in the Technics.

 

[Sonik Wiz]

I hear Tate made a good decoder. But Hafler can be fun too.

Yes Sir Hafler can be fun. I prefer the slightly different EV-4.
Tate never made a decoder. Fosgate Audionics made a couple of great decoders that used the Tate DES (Directional Enhancement System).

 

[quadsearcher]

Yes Sir Hafler can be fun. I prefer the slightly different EV-4.
Tate never made a decoder. Fosgate Audionics made a couple of great decoders that used the Tate DES (Directional Enhancement System).

Thanks.
I thought i saw a mention of the the name on a faceplate of a decoder (or in a description of it) so thought it was part of the brand. . https://www.quadraphonicquad.com/forums/threads/fosgate-tate-ii-101a.1552/
My mistake. While in common usage the Tetrasound, or maybe the Fosgate 101A have been referred to as Tate, I was being lazy.
I'm just getting over a mild bout with covid. Have some time on my hands to be goofy I guess.