Gain Riding Logic - did it ever sound good?

[national-kid]

Happens all the time...Companies declare a technology as "commercial" too soon and their potential customers sour on it.

I think that the digital surround standards in recent years are much worse than they were in matrix surround. (People don't learn. History repeats itself over and over.)

 

[Doug G.]

The thing I remember most about when I first read about SQ was the "helical motion" aspect of groove modulation and, at first, trying to imagine a stylus moving in a helical way which, of course, a stylus in a stereo cartridge cannot do.

Doug

 

[par4ken]

Can you say "Double Helical Modulation"! I love that term as much as Thermionic Valve!

As for those 3dB decoders I used my Audionics 106A for years and it sounded great. I preached the gospel of quad to everyone! While not everyone was wowed (only discrete could really do that) I was forever sold. Even that simple Dyna style speaker connection was so much better than straight stereo.

But I do agree that greed caused the premature release of products as well as (even more so) the premature end to the enterprise.

 

[Sonik Wiz]

Can you say "Double Helical Modulation"! I love that term as much as Thermionic Valve!

As for those 3dB decoders I used my Audionics 106A for years and it sounded great. I preached the gospel of quad to everyone! While not everyone was wowed (only discrete could really do that) I was forever sold. Even that simple Dyna style speaker connection was so much better than straight stereo.

But I do agree that greed caused the premature release of products as well as (even more so) the premature end to the enterprise.

My long gone girlfriend Jann said I was greedy and scolded me for premature release. Despite the helical modulation.

 

[ar surround]

My long gone girlfriend Jann said I was greedy and scolded me for premature release. Despite the helical modulation.

 

[chucky3042]

I can't help but notice the low frequency drop off below ~100Hz for both the Sansui and Surround Master decoders, the other decoders are basically flat to 20Hz, any idea why this is so?


Kirk Bayne

It tests flat on tone.......dunno

 

[chucky3042]

Perhaps what's most interesting is that matrix encode quad remains fascinating to this day. It was fascinating to me back then and it is so now. Anyone can make a discrete recording, but matrix encoding/decoding is black magic.

Thats one of the reasons I like it, there is still the romance/ black magic

 

[Sonik Wiz]

I love ya man!

 

[par4ken]

I can't help but notice the low frequency drop off below ~100Hz for both the Sansui and Surround Master decoders, the other decoders are basically flat to 20Hz, any idea why this is so?


Kirk Bayne

Is that a measured result or subjective? I have noticed (subjectively) a reduction of bass with a number of different decoders. The Audionics S&IC has no such bass loss, what goes in comes out! I replaced the output coupling caps in my QSD-1, changing from 1µF to 10µF, the same as in the Composer. The (subjective) bass response is now is about the same as with the Composer. So do most decoders use too small an output capacitor? You wouldn't think so unless the unit is driving a very low impedance.

The only other thing is that QS uses a lot of anti-phase blending, if the bass is recorded as mono as is usually the case with LP's, then some bass would cancel. When using Surround mode (which I mostly do) out of phase blending is applied before the stereo signal is even decoded and so bass loss could occur. When Scott designed his original pre-synth circuit he added in a capacitor to prevent bass blending and thus avoiding cancellation of the bass.

 

[J. PUPSTER]

My long gone girlfriend Jann said I was greedy and scolded me for premature release. Despite the helical modulation.

Dude, TMI, restrain yourself!

Is that a measured result or subjective? I have noticed (subjectively) a reduction of bass with a number of different decoders. The Audionics S&IC has no such bass loss, what goes in comes out! I replaced the output coupling caps in my QSD-1, changing from 1µF to 10µF, the same as in the Composer. The (subjective) bass response is now is about the same as with the Composer. So do most decoders use too small an output capacitor? You wouldn't think so unless the unit is driving a very low impedance.

The only other thing is that QS uses a lot of anti-phase blending, if the bass is recoded as mono as is usually the case with LP's, then some bass would cancel. When using Surround mode (which I mostly do) out of phase blending is applied before the stereo signal is even decoded and so bass loss could occur. When Scott designed his original pre-synth circuit he added in a capacitor to prevent bass blending and thus avoiding cancellation of the bass.

Now this is some interesting info I need to digest; please take note Scotty banger boy

 

[kfbkfb]

AFAIK, the CBS Professional SQ decoder (model 2400?) used gain riding logic exclusively, I believe this SQ decoder was provided to the BBC for their SQ matrix evaluation in 1974 (SQ didn't do well in the tests).

Anyone heard this gain riding only SQ decoder?


Kirk Bayne

 

[tonyE]

My long gone girlfriend Jann said I was greedy and scolded me for premature release. Despite the helical modulation.

You introduced too much Intermodulation Distortion into your RMS harmonic motion.

Next time remember than 2nd order harmonic distortion is much more pleasant that 3rd order!

And don't push it too much or you'll run into clipping.

 

[Doug G.]

My long gone girlfriend Jann said I was greedy and scolded me for premature release. Despite the helical modulation.

Did you tell her her bass was flabby and not tight?

Doug

 

[ar surround]

I can't help but notice the low frequency drop off below ~100Hz for both the Sansui and Surround Master decoders, the other decoders are basically flat to 20Hz, any idea why this is so?

I do find myself boosting the bass with the Surround Master on much material. (Some of this is due to the room: The SM is connected to directly to a second set of analog inputs and not subjected to Audyssey room correction.)

 

[MidiMagic]

True... you ought to see her drive a stick shift and shift at redline while wearing 4 inch pumps... amazing.

Reminds me of how gain riding behaved.

 

[par4ken]

AFAIK, the CBS Professional SQ decoder (model 2400?) used gain riding logic exclusively, I believe this SQ decoder was provided to the BBC for their SQ matrix evaluation in 1974 (SQ didn't do well in the tests).

Anyone heard this gain riding only SQ decoder?


Kirk Bayne

I thought that SQ did well in the tests. BBC wanted 100% mono compatibility, that's why they came up with Matrix H. A complete waste of time and money IMHO.

 

[MidiMagic]

Absolutely correct! How could anyone release a quadraphonic decoder with 3db of separation and think it's good? Greed.
And it was greed that caused all the different systems, too. That's why we had 33rpm and 45rpm, VHS and Beta, etc, etc. Eventually, one typically wins out, but in the case of quad, it was too many and too confusing.

I thought it was good at 3 dB (I couldn't stand the cogging effect of discrete.). The Dynaco diamond was especially good.

Part of the problem was intellectual property, patents, and royalties paid to patent holders. Greed. Every company wanted its own system to be the standard, so they didn't have to pay royalties.

We got stereo records without these problems because it was patented in 1933 and the patents had already expired. There were no royalties on the 45/45 system.

If greed was the only reason, we would have had QS. Sansui offered its system royalty-free ... except that all of the matrix royalties belonged to Peter Scheiber as determined in court. His patent was general enough to cover all matrix systems.

 

[barfle]

Wife happy, me happy... and, with all of this working from home, my "under the radar" expenses are now up to $700 and my "make up my own mind, don't need approval" is up to $1000... so I'm happy (she handles the bills).

Off topic, I know.
When we got married, we figured out a way to not fight about money. Both of our oaychecks went into a joint account, and we each had our own accounts that were supplied by an allowance, which has increased over the 46 years since then. I spend my money my way, she spends hers however she wants. She usually pays the bills, but it’s not an obligation. She just likes to be confident.

 

[Sonik Wiz]

Absolutely correct! How could anyone release a quadraphonic decoder with 3db of separation and think it's good? Greed.
And it was greed that caused all the different systems, too. That's why we had 33rpm and 45rpm, VHS and Beta, etc, etc. Eventually, one typically wins out, but in the case of quad, it was too many and too confusing.

At the risk of being serious for a moment, your comments are thought provoking both in specific and the big picture.

Specifically a quad systems with 3dB separation (that both SQ & QS were guilty of isn't much) but for a center L/R or center F/B the Sansui system offered ~7dB separation. Enoch Light & his Ping Pong Brigade sounded pretty dramatic in that situation.

The 45 RPM record was not a competing technology but a complimentary one so teenagers could spend less $$ to sample & get hooked on a song & then spend more $$ on the album.

True that, about VHS & BETA, and don't forget the various video disc systems. Is this motivated by greed? I see greed as an excessive desire for wealth and power. The key word is excessive. In a free market capitalistic economy when a technology or service is being considered the two questions asked is: does it have value to the consumer? Can money be made from it? Certainly any business wants to make money & have the dominant product. While there are examples of greed in this case it seems mainly of offering to the public today what can be done today, whether it is 1972 or 2022. I mean we can do things today in audio that we couldn't do 20 years ago. What of all the in between ? Should it have been kept in the lab waiting to be perfected?

In high school I had a friend whose dad owned a color separation company. They took photographic images & separated them into individual colors lith films to make CMYK four color printing plates, for ink on paper reproduction. He knew quality color. He lived quality color. He said he would never buy a color TV until it was perfected. He died with a B&W TV.

So these techno-trips can be quite evolutionary. I've certainly enjoyed the journey over the decades.

 

[kfbkfb]

IMHO, Dolby Labs had the right idea - monitor Dolby Surround encoded mixes thru a Dolby Pro-Logic (1) decoder (it's a roundabout way of saying compromise the mix so that the limitations of Dolby Surround are rarely audible)

If only CBS had required monitoring thru an SQ decoder (maybe a Sony SQD-1000 at minimum), it might have helped hide the limitations of SQ encode/decode.


Kirk Bayne