QSD-2 or QRX-x001?

[KeithD]

I currently have a QR-6500 and QR-4500. However, would like the Vario-Matrix experience. I'm wondering which would be the better route: getting a QSD-2 to plug into my QR series receiver (currently just using the 6500 in quad mode.) Or, look for a QRX-x001 receiver? If I do that, I prefer the aesthetics of the 8001/9001; however those are fairly expensive and seem to need significant maintenance/are difficult to work on. The 7001 and below would be ok, but no better looking than the QR series. I am very impressed with the build quality of the 6500/4500, and have no troubles with either. I assume the QSD-2 would be zero maintenance?

So, which makes more sense? The QSD-2 seems to sell for around $400 on the auction site, which seems like a lot, but the only alternative seems to be buying a QRX-x001 receiver for about that much (5001, 6001, 7001) or much, much more (8001/9001).

 

[kevzep]

The QRX8001 is a sleeper, doesn't have that dreaded Dolby Board, I'd be heading towards that......

 

[Sansuiman]

The 8001 is indeed a sleeper. Just slightly less power than the 9001, and no problematic Dolby section as Kev stated. BUT...it still has the same dreaded board with the via's (pass through joints) as the 9001 so that much will still need attention unless you find an 8001 already so restored.

The 8001 does sometimes come up at a surprisingly decent price - relative to what a 9001 fetches these days anyway - if you are willing to lay in wait for the right opportunity.

If you have two QR's already, and they both work well, the QSD-2 may be worth considering to use with one of them. If you buy an 8001 and have it restored you are probably going to be near 3x the typical price of a QSD-2, all in with purchase and restoration costs.

Sound characteristics of the QR-4500/6500 amplifier section are not much different to my ear from the 8001/9001 (I own a QR-6500 a QRX-9001 and a 999 so have made the comparison myself), excepting lower WPC ratings. Neither QR is a slouch power-wise, unless you happen to have difficult or very inefficient speakers, and the 8001/9001 aren't that much newer that there was a major advance in amp design between them and the QR series.

Aesthetically speaking, yes the 8001/9001 are great looking units, and cast a rather imposing presence. They clearly mean business, and present notably more complexity - for those who like that kind of thing - with the added power meters and sheer number of different controls on the panel. And I do understand that despite this being about sound, looks do matter to many vintage collectors. I know I enjoy a good looking stack of gear, and the 9001 is a good anchor for one no doubt.

If pursuing a 8001/9001, figure on budgeting $1100-1800 to buy and have professionally restored. That's a chunk of change, and while the QSD-2 isn't what I'd call cheap, it is more easily attainable and will provide the very same quad decoding and synth functions as an 8001 or 9001 when coupled to a four channel amp.

 

[KeithD]

Thanks for the detailed reply. I know what you are saying about the 8001/9001. QRX Restore gets $1385 for their complete service! So, yeah, that's on top of the purchase price. Seems like most say that even if you get an 8001/9001 in working condition, it WILL need service/restoration. I have yet to tackle a double sided board. There is one in my Pioneer SX-828 and I'm not sure I'm going to take that on. Currently doing battle with restoring a Pioneer QX-949, and not liking it! Will not do another.

I agree with your analysis from a price standpoint, the QSD-2 would be a much less expensive route. Since you have both QR-6500 and QRX-9001, what is your opinion about the differences you hear between the two with respect to synthesized quad? Is the 9001 that much better than the 6500? I'm just wondering if it is worth the investment to upgrade my QR listening? I really wish there was one in my area I could listen to. Not unhappy with the sound of the 6500/4500, but I've never heard Vario Matrix. Don't feel like spending lots of money for only incremental improvement.

Aesthetically the meters would be nice, but I would not buy an 8001/9001 just for that. After looking at the QRX-x001 series, I would not be able to use a 7001 or lower as my sole receiver, since they don't have enough inputs to meet my needs (Phono, CD/Aux 2 channel, two 2 channel tape in/out, one 4 channel SACD). So, I'd need to have an 8001/9001 or 5500/7500, but the latter two do not have the best decoders/synthesizers.

 

[KeithD]

Actually, now that I look at the 9001 owner's manual, I see it only has 4 inputs: phono, 2 channel tape, 4 channel tape, and 4 channel AUX. The 8001 has an additional connection of "Dolby Adapter" in and out. Can that be used just like a tape connection? If so, that gives a 5th input. If not, even the 8001 would not have enough inputs for me.

 

[Sansuiman]

Yes, the Dolby adapter in/out functions identically to a tape monitor loop so could be used as an added input. Not sure if it is routed before or after the tape monitor loops on the 8001, so if you are using outboard processors (like and EQ) it may or may not affect the source attached to the Dolby adapter loop.

Source routing on the 9001 is a bit odd too, as far as the auxiliary input is concerned, since it is a separate toggle switch independent of the rotary source selector. I still wonder why Sansui designed it that way rather than adding an additional position to the rotary switch. There is no technical reason apparent to me why it wasn't done that way, but I suppose they had a reason.

 

[KeithD]

Yes, the Dolby adapter in/out functions identically to a tape monitor loop so could be used as an added input. Not sure if it is routed before or after the tape monitor loops on the 8001, so if you are using outboard processors (like and EQ) it may or may not affect the source attached to the Dolby adapter loop.

Source routing on the 9001 is a bit odd too, as far as the auxiliary input is concerned, since it is a separate toggle switch independent of the rotary source selector. I still wonder why Sansui designed it that way rather than adding an additional position to the rotary switch. There is no technical reason apparent to me why it wasn't done that way, but I suppose they had a reason.

OK, thanks. The QSD-2 is looking more flexible and certainly more affordable. Could also use it with my Pioneer QX-949 once it is restored. Do the boards in there generally need reconditioning, or are they pretty reliable as is?

Thanks!

 

[Sansuiman]

I've not seen the inside of a QSD-2 so am it sure if it uses a dual sided board as in the 8001/9001, but I suspect not, or at least not the same board as used in the 8001 and 9001. I've not read any accounts or poor reliability from the QSD-2 in any case, after 22 years of collecting Sansui gear and hanging out in forums that discuss it.

Qsd-2 is functionally the same decoder/synth circuit used in the QRX 7001-9001, all of which were derivative (and slightly decontended) versions of the reference version fitted in the QSD-1. Bottom line, a QSD-2 gets you the very same QS quad functions and performance as a QRX-7001-9001, less the SQ and CD-4 modes present on the 8001 and 9001.

If you think you want to add SQ and CD-4 decoding to your setup, an 8001 or 9001 makes more sense, or you'll end up needing other outboard decoders for those formats. Depends on how hard core of a quad listener you are, or may plan to be. I've not used either format myself, but there seems to be consensus the Qrx-8001/9001 CD-4 capabilities are very good, while the SQ decoder is deemed adequate from my reading on the subject.

 

[sKiZo]

Don't discount the x6-7001 receivers. Same vario-matrix system as their bigger brothers if you don't need the power or can get beyond the aesthetics. I got a 6001 on the cheap as a backup when I put my 9001 on the bench and it did yeoman duty here. Worked well enough in fact it took me about a year to finish the 9001's restoration ... <G>

PS ... I run an outboard amp on the front channels, so power wasn't a concern. Can't say I was all that impressed with the looks, but nothing a paper bag couldn't cure ... ;-}

I DO think the SQ mode is a necessity ... I run most of my stereo source thru the SQ decoders with excellent results. Only time I use any of the other modes is for material I know is encoded in QS or CD4. I seldom use the matrix and usually reserve the hall mode for orchestral.

 

[sKiZo]

Worth mentioning, make sure you've got some extra room in the rack if you go with an x8-9001 ... them suckers is HUGE. I built my cabinet with one of those monsters in mind. On the plus side, that gave me plenty room for a larger monitor for the HTPC ...

 

[KeithD]

Qsd-2 is functionally the same decoder/synth circuit used in the QRX 7001-9001, all of which were derivative (and slightly decontended) versions of the reference version fitted in the QSD-1. Bottom line, a QSD-2 gets you the very same QS quad functions and performance as a QRX-7001-9001, less the SQ and CD-4 modes present on the 8001 and 9001.

If you think you want to add SQ and CD-4 decoding to your setup, an 8001 or 9001 makes more sense, or you'll end up needing other outboard decoders for those formats. Depends on how hard core of a quad listener you are, or may plan to be. I've not used either format myself, but there seems to be consensus the Qrx-8001/9001 CD-4 capabilities are very good, while the SQ decoder is deemed adequate from my reading on the subject.

QSD-2 has both QS and SQ decoding, but not CD-4 (which I have no use for.) Only have one SQ record I bought out of curiosity when I picked up the Pioneer quad. I would use the synthesizer function almost exclusively.

 

[KeithD]

Another benefit of a QSD-2 (or -1) would be that I would not be tied to one receiver. I could use it with any quad receiver and still have the benefits of vario matrix. If one receiver goes down for service, I just hook the box up to another one. I plan to have two quads in my collection for sure. One will always be a backup.

 

[Sansuiman]

Ok, I had forgotten the QSD-2 has QS well as SQ. And yes, having an outboard decoder means you can use it's capabilities with any amp or receiver (although if using with a stereo amp, will need a second for the rear channels of course).

It does give you more flexibility and doesn't require the space of one of the heavy hitter receivers. Even the 7001 is a large form factor receiver, even if not to the same extent as the 8001/9001. The QX-949 is a big boy too, as are the QR-4500/6500.

 

[KeithD]

Sansuiman, since you have both QRX-9001 and QR-6500, could you comment on the synthesized quad sound of each?

Thanks!

 

[Sansuiman]

I've found the QR-6500 synth mode to be entirely unimpressive versus the Vario-Matirx synth mode. I hate to say that as the QR series receivers are quite well built, but the quad performance has never done anything at all for me. Outside of that shortcoming, they are great solid units.

Now, I have a sample size of one to go by, so perhaps my 6500 is not in spec (I've done nothing to it save for cleaning the controls and replace some bulbs) and isn't working as intended. I got the 6500 as part of a package deal, years after I already owned a couple of 9001's so my impression was colored a bit I'm sure by starting off with the more advanced model QS gear and then hearing the earlier iteration.

The 6500 isn't in rotation right now, but when last used I had a QSD-1 mated to it for quad synthesis mode, and ignored the integral quad capabilities as I just didn't care for the way it sounded compared to a 9001 in surround synth mode. And I did give it a fair shake before I made came to that determination.

 

[sKiZo]

I drove a QR here for years and can't say it ever disappointed me for sound quality. Biggest difference was having the SQ mode available ... as mentioned earlier, I run most of my stereo material through that with outstanding results.

Ladies and germs ... fire up ... the wayback machine!! Here's my quad system circa 1970ish. Check out the QR4500. Bought that from a little old priest in Pasadena I did ...

PS ... worth mentioning - an amazing amount of material was either SQ or QS encoded without it being specifically sold as such. QuadraphonicQuad has the bible on what's what if you're interested in experimenting around.

And ... the QR series had a lot more I/O if you're into that sort of thing. More speaker outputs, pre out, etc ... quite the workhorse if you want to run a few rooms on one receiver.

 

[KeithD]

I've found the QR-6500 synth mode to be entirely unimpressive versus the Vario-Matirx synth mode. I hate to say that as the QR series receivers are quite well built, but the quad performance has never done anything at all for me. Outside of that shortcoming, they are great solid units.

Now, I have a sample size of one to go by, so perhaps my 6500 is not in spec (I've done nothing to it save for cleaning the controls and replace some bulbs) and isn't working as intended. I got the 6500 as part of a package deal, years after I already owned a couple of 9001's so my impression was colored a bit I'm sure by starting off with the more advanced model QS gear and then hearing the earlier iteration.

The 6500 isn't in rotation right now, but when last used I had a QSD-1 mated to it for quad synthesis mode, and ignored the integral quad capabilities as I just didn't care for the way it sounded compared to a 9001 in surround synth mode. And I did give it a fair shake before I made came to that determination.

This is what makes me so interested in hearing Vario-Matrix. I started out with Pioneer SA/TX-8100 driving A and B speakers, with the B speakers in the rear run through a Pyle speaker volume control to attenuate the rear sound level. Thought that was pretty good. Then I picked up a Pioneer QX-949, and thought the simulated SQ or RM quad was a noticeable step up. Then picked up a Sansui QR-4500, and was shocked that it sounded even better at simulated quad than the Pioneer 949. I think that is saying a lot about Sansui quad technology - the bottom QR receiver sounds better than the TOTL Pioneer in simulated quad, though most Pioneer collectors acknowledge Pioneer quad technology was not that good, but the 949 does look goooood!

So, now I wait with anticipation to hear Vario-Matrix. I hope it's all I anticipate!

Nice setup sKiZo! A lot of extra components there. Not sure what all of them are!

 

[sKiZo]

Me neither ... <G>

Here's a basic tour of the system I put together a while back. I really should update it someday as there's been a few changes ...

See sKiZo's system!

 

[KeithD]

Me neither ... <G>

Here's a basic tour of the system I put together a while back. I really should update it someday as there's been a few changes ...

See sKiZo's system!

Very nice tour of your system, and nice setup! Way more than I'd be able to keep track of, but sure is cool!

 

[Hipocrates]

Here's a basic tour of the system I put together a while back. I really should update it someday as there's been a few changes ...

Pretty cool stuff man!