Subject: Re: sansui QS500
Only the QSD-1 utilized 3 separate Vario-Matrix decoders, they gave in to simplicity after that. Not even the coup-de-grace QSD1000 went over a single band after that. D1s were used to decode the first run of “Star Wars” and the even earlier “Tommy”. But a well tuned QSD-2 (and I include the QRX 6001,7001,8001and 9001 receivers here) can sure come close. As far as I know, the receiver series put the entire QSD2 into them, not cut down versions like some demodulators were. The main problem with the receiver units is that beside sucking off a common power supply (no great shakes to a Sansui really) you could NOT record the 4 channel DECODED output from them unless you went through the headphone jacks. Curious, because you COULD on the non Vario Matrix receivers (QR4500 and 6500).
The problem with the outboard QSD-2 is the same problem with the QSD1, QSD 1000, and the Tate, RARITY and EXPENSE !! I’m STILL kicking myself for selling the D2 I had back in the 80s, I’ve never seen or heard of one since. The other difference between the D1 and 2 is the SQ decoder on the D2, which is OK if you haven’t been spoiled by Tate or CBS.
I guess I should ask at this point which receiver you have (and if I can get it off of you <g> ). The type B Vario-Matrix was actually earlier, the main difference being in components, and a slightly lessamount of front-rear separation. Again, a well tuned one (and they’re a bitch to tune) gives a type A a run for its money, everything still goes to the same quadrant, but the sound-field is much “closer” to you. A fun thing on the type Bs is they often had more modes, ie, I have a QRX-5500 that has QS synthesizer Hall, Qs Synthesizer Surround, QS Hall, and QS Surround, along with “Phase Matrix”a n earlier form of Vario-Matrix SQ. The
differences are sometimes subtle, sometimes gross. The type B receivers were flashier (power meters,etc) except the 8001/9001,which were styled curiously after the aforementioned type B’s. The 6001 and 7001 were rather plain, but much better build quality than the 8001/9001. Also the B receivers had more inputs. Strange that Sansui never put all of its eggs in one basket, the 9001 is woefully lacking in inputs, IMHO.
That’s the ones I know about. There’s QSD4’s out there somewhere, maybe I’ll get to hear one someday. Come to think of it, I’ve never seen or heard a QSD-1000 either. BTW, the QSD1 can take preamp level input.
The search for the Grail goes on………..
Subject: Re: sansui QS500
QS and other type of decoder, and one of the switch positions is labeled QS. This gear is painted flat black with white silk screening. It has a simple look that is intended to appear professional, and is rack mountable. This is stereo gear, but obviously they expected that
people would stack it in racks and use it for quad as I am doing. I wonder if a QS decoder was ever built in this style? Oh well, I’ll be lucky just to get my hands on any decoder with Vario-matrix circuitry.
I will more than likely use the receiver to make a matching decoder that will rack mount, unless I find a QSD-1. It has a CD-4 unit, and I could build a combo decoder out of it. It is a QRX 5001. What do you know about the decoder in it? Thanks, The Quadfather
PS: by the way, you wrote “the other difference between the D1 and 2 is the SQ decoder on the D2 which is OK if you haven’t been spoiled by theTate or CBS. CBS? What’s CBS?
The 5001 is a type B Vario. The QSD-1 is rack mount,a s are the QSD-4 ( I believe) and the QS encoders, I had a QSE5B years ago that was a twin to the QSD-1 physically. CBS made a series in the 70s that was actually made in America, the CBS SQL-200 and the SQL-400A. The 200 was even available in kit form. The 400 was the first SQ decoder I ever heard
that made me think the matrix actually worked, it had phenomenal separation for its time (25-35 db between corners) and even had LOGIC assisted stereo synthesis. Logic was fully adjustable. Apparantly only 100 were made, I’m not sure on the 200,a nd never released to the general public. This unit really foreshadowed the Tate and Audionics decoders that came later. (Im still kicking myself for selling THIS one too.) Also, a bunch of 400’s were made in 200 cabinets, and proclaimed that they were 400’s by a sticker on the back. If you ever see or hear of either of these,GRAB IT!
Subject: Re: Tate “Surround” = QS?
The 7001 and lower were using Sansui’s own (sounds like salad dressing, don’t it?) CD-4 chips, while the 9001 used JVC chips and had automatic carrier level as well, I really liked the demodulator when my 9001 used to work. I find the Tate decodes QS very weirdly, I think a lot of it is out of phase material directed to the wrong quadrant(s). Tab, you haven’t lived till you’ve heard QS through a PROPERLY calibrated Vario-Matrix decoder. Every one I’ve met has needed alignment. There are simple to complex mods you can do also. I know, WHERE ARE THEY? I’ll be home in N.M. next month and I’ll run off a bunch of copies for anyone interested, for cost or interesting swaps. Never let it be said that I’m selfish 🙂
Subject: Re: Make money, Earn fame
Here’s something: the QRX3000 used a decoder built out of Discrete components, it qualifies as a Type B, but it can possibly be built as it uses no IC’s. Trouble is, I’ve never seen a schematic for one, the service manual has a big whited out section where the decoder goes (talk about Xfiles). Also, we would have to look at improving the front-rear
separation, something the type A’s did by adding IC’s to the later typeBs. Anyone ever seen any documentation on any Type B Vario???
Subject: Re: Variomatrix Decoder
Outboard Sansui Varios are nigh impossible to get (a QSD1 is on ebay right now,over 500 bucks and still going) I haven’t seen or heard of a QSD-2 in 15 years, next best would be a Vario-Matrix reciever, namely, a QRX 6001, 7001, 8001, or 9001. They are fairly easy to preamp if you want more power output, and they all contain the QSD2 decoder/synth.