I am so sorry if this has been chewed on at length already....

[myquadquestions]

Here's my question, and thanks for any help.

In the 70's I worked for Lafayette Radio. At that time, I believe I had a simple Lafayette SQ-L.

Here is how I used it, and here is what I am looking for now.

I only used a stereo input, like from vinyl. I only wanted the difference between the channels for my rear speakers. Just the weird extracted stuff.

You know, where you just hear guitar, and synth, and the bass and drums were gone.

Or where you hear the reverb a lot more, and or the vocal or guitar can disappear.

I totally forget how I hooked it up, as I thought that I had the cheaper SQ-L. I think that mine is old and broke.

I am old, but not broke, thank goodness.

So, here I am,....with an old SQ-W, and a SQ-L, and I cannot get either to work. I do not have a SQ-M.

And what ins and outs should I be using to achieve this, and what unit?

I also don't remember if I was using the SQ setting or the Composer. I think it was the SQ that would extract the difference between channels.

Anyway, should I get these fixed? Just buy a good working SQ-W online, or what other Lafayette unit, or forget it, and just get a Fosgate Tate, 101 and call it a day.

And will the Fosgate Tate do what I want?

I want a rear synthesized dual channel of extracted information, given a stereo input signal.


Thanks again. I truly appreciate the help.

 

[Clint Eastwood]

Welcome to the forum

 

[Robert van Diggele]

Mqq, welcome.

 

[4-earredwonder]

Here's my question, and thanks for any help.

In the 70's I worked for Lafayette Radio. At that time, I believe I had a simple Lafayette SQ-L.

Here is how I used it, and here is what I am looking for now.

I only used a stereo input, like from vinyl. I only wanted the difference between the channels for my rear speakers. Just the weird extracted stuff.

You know, where you just hear guitar, and synth, and the bass and drums were gone.

Or where you hear the reverb a lot more, and or the vocal or guitar can disappear.

I totally forget how I hooked it up, as I thought that I had the cheaper SQ-L. I think that mine is old and broke.

I am old, but not broke, thank goodness.

So, here I am,....with an old SQ-W, and a SQ-L, and I cannot get either to work. I do not have a SQ-M.

And what ins and outs should I be using to achieve this, and what unit?

I also don't remember if I was using the SQ setting or the Composer. I think it was the SQ that would extract the difference between channels.

Anyway, should I get these fixed? Just buy a good working SQ-W online, or what other Lafayette unit, or forget it, and just get a Fosgate Tate, 101 and call it a day.

And will the Fosgate Tate do what I want?

I want a rear synthesized dual channel of extracted information, given a stereo input signal.


Thanks again. I truly appreciate the help.

My answer would be a resounding NO. Those old Lafayette Receivers were well thought of in their day but if you have the $$$$$, upgrade to a newer and more powerful new receiver with HDMI inputs and ALL the latest decoding modes.

Those Lafayette receivers weren't very powerful [I had one] and SQ/QS modes were to mildly put it....subpar.

Besides, finding someone to repair them and the cost of replacement parts [likely unavailable] would probably cost you more than the price of a new receiver.

BTW, WELCOME to QQforum!

 

[Quadzilla]

If I understand the OP correctly, he is looking for the best way to synthesize quad sound from stereo sources. I have a Tate decoder and it is excellent, but they are now quite old and parts are VERY hard to find … if not impossible. My suggestion would be to get a Surround Master from Involve Audio … http://involveaudio.com/surround-master/ There are plenty of posts about it on QQ.

 

[Soundfield]

I only wanted the difference between the channels for my rear speakers. Just the weird extracted stuff..

If that's all you want, it's incredibly easy to do by just hooking up your rear speakers between the positive terminals of your front speakers (known as the Hafler circuit if you need to look up the details). If you want to do it at line level to feed into a separate amplifier, and you can solder, it's also pretty easy - you just need an op amp configured as a difference amplifier. Have fun - the Hafler connection (although not a "quadraphonic decoder") works surprisingly well with a lot of stereo material.

 

[Quadzilla]

The Hafler method does work quite well with some stereo sources, but not all amplifiers are stable with this type of hook-up. Use with caution.

 

[ar surround]

The Hafler method does work quite well with some stereo sources, but not all amplifiers are stable with this type of hook-up. Use with caution.

Yes, be careful. Some people have blown out amps with this Hafler / Dynaquad hookup.

 

[myquadquestions]

Hey, thanks to all for the great responses.

"If I understand the OP correctly, he is looking for the best way to synthesize quad sound from stereo sources"

Yes, this is correct. I'm not looking for a receiver. I have 2 separate power amps, and a nice preamp with multiple outs.

I just want the processor. It looks like the surround master is tricky to find used.

 

[Quadzilla]

The Surround Master is likely hard to find on the used market, but a Tate isn't easy to find either. The Tate is a good unit, and mine was serviced by Bob Popham, but my Sansui QSD-2 stand-alone Variomatrix decoder does a better job of synthesizing stereo sources into quad. I understand that the QSD-1 is better, but a lot more expensive. Another option would be to get an older preamp/processor with Dolby Pro-Logic II.

 

[Soundfield]

"If I understand the OP correctly, he is looking for the best way to synthesize quad sound from stereo sources"

Yes, this is correct.

Sorry, I misunderstood, I thought you only wanted to perform stereo difference extraction.

 

[myquadquestions]

Thanks!

What I believe the old Lafayette unit did was to extract the "difference" between the 2 channels. Anything that was the same in both channels would cancel each other out, and make it disappear in the mix.

Strange guitar parts would pop out. Certain BGV's would pop out.

This is what I am looking for. So, in a sense, yes....

"I want to perform stereo difference extraction", .... using a processor to only process "extracted differential" sound for my rear speakers, independently powered.

Thanks again for all the help here. This is a very cool site. Glad I found it!

 

[Soundfield]

Thanks!

What I believe the old Lafayette unit did was to extract the "difference" between the 2 channels. Anything that was the same in both channels would cancel each other out, and make it disappear in the mix.

Strange guitar parts would pop out. Certain BGV's would pop out.

This is what I am looking for. So, in a sense, yes....

"I want to perform stereo difference extraction", .... using a processor to only process "extracted differential" sound for my rear speakers, independently powered.

Thanks again for all the help here. This is a very cool site. Glad I found it!

Ok, well that is exactly what the Hafler connection of rear speakers achieves (but it isn't in any sense quad synthesis in the way that the Surround Master for example operates - that is a much more sophisticated approach). I never had any problems using it with any of a vast array of amplifiers back in the day (it only adds a tiny percentage load increase to the output stage) but latterly I wanted to try and do it at line level anyway so I could control the front / rear balance more easily - so built a simple op amp difference amplifier into this little box :

Not as complicated as it looks since the difference circuit and buffer is just that single chip on the Vero Board - the rest is the regulated power supply!

 

[myquadquestions]

Thanks.

OK, so here is my question......

If I get a surround master, or a Fos-Tate does it goes in between my line preamp and power amp?

Or does it need a tape loop, ins and outs?

Let me be specific. I am using a Marantz SC-7S2 preamp.

I have multiple outs. I use one set of cables out, and into one Parasound power amp for my fronts, and a second out into a second Parasound power amp for my rears.

Can I leave the fronts as they are, and simply patch in the surround master in between output #2 and amp #2, JUST for the rears, and just use the rear outs of the processor,

OR!!!.....do I run one preamp output set directly to the surround master, and then direct all 4 outputs from the sound master outputs of the 2 power amp?

Thanks again for the assist.

 

[Soundfield]

If I get a surround master....

That's a big IF - the SM has not been available from Involve for some while now (and I've never seen one come up second hand) - a lot of us here are desperately waiting it's promised replacement in pre-amp form. Time for Chucky to update us on what, if any, progress there's been on that front perhaps?

 

[myquadquestions]

How does the Surround Master wire into my system, and does it go between the preamp and amp?

Why do I see this question about "compatability" ? Can it be used with a nice preamp, and 2 power amps?

Am I missing something?

And will this SM do pretty much what I am looking for, as I have expressed it?

THX! Again!!!!!!!!!!!

 

[myquadquestions]

If I could find a SM, would I need the one with SQ or without to achieve my goal?

Is SQ only for stereo input that is 4 channel encoded?

Sorry for all the questions.

And how would you compare the SM vs the Fos-tate?

THX~

 

[Soundfield]

How does the Surround Master wire into my system, and does it go between the preamp and amp?

This is what the SM handbook says :

"4ch - Four Channel Surround
PRE AMP to AMPLIFIER If you are connecting from a pre-amp to the input of the Surround Master, connect front and rear from the 4 CH SURROUND outputs of your Surround Master to the inputs of your POWER AMP (multichannel, or 2x stereo amplifiers, 4 x monoblocks and so on)
DIRECT to AMPILIFIER If you are connecting directly from your source (CD, DVD etc) to the input of the Surround Master, connect front and rear from the 4 CH SURROUND outputs of your Surround Master to your receiver amplifier (multichannel) inputs."

Connection is simple and if you can ever find one you'll find it works fantastically well (but if you only want it for synthesis and have no SQ encoded material to decode then, of course, you do not need the SQ version).

 

[myquadquestions]

Thanks to all for the great info.

It is really appreciated!!!