Dynaco 4-Dimensional Stereo Demonstration Disc

18 May

Dynaco 4-Dimensional Stereo Demonstration Disc

Vanguards first demonstration disc, which was later reissued in SQ, although slightly altered

Reference Series Releases contain:

Original DY encoded Stereo file for personal decode evaluation (MLP only)

DYd decoded versions on MLP, DTS,AC-3

 

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EV-4: The Mystery Solved? – Part II

16 May

Something i should have added in the first part of my investigation is that not all of the ‘QD’ releases are subject to having been released in EV-4 and QS formats. The last EV-4 encoded release appears to have been 5051 (Enoch Light – Big Hit Movie Themes) so it’s fair to say that any album from 5052 onwards marked QD is QS.

Now i will attempt to show how it is ‘possible’ to distinguish an EV-4 encoded album from a QS one, although i must state that when it comes to QS encoded albums the pictures may not be so clear cut, the visual phase response is just a snapshot of a rather complex mathematical  equation, so if you attempt to try this method yourselves, please take your time! Hopefully you’ll see why.

Unfortunately i don’t have more than one copy of any of the Project 3 quad albums so i’m unable to show how a particular albums visual phase response difference compares between the two, but i’m sure that the two albums chosen will give an adequate picture, so to speak.

We’ll start with one of the demonstration albums that were only released using EV-4. This is the album i released a few days ago, ‘Enoch Light – 4 Channel Stereo’. The first picture shows the standard waveform of the complete album that was used for decoding purposes, and included on the release.

The next view is a snap shot of the waveforms spectral phase. It would be very easy to take too much notice of this as it only shows a visual representation of what the program sees and isn’t truly correct, but for the purpose of this experiment it will be more than adequate.

As you see, there is a large amount of zero phase information on almost every track, surrounded by large amounts of random phase information, including some small amounts of out-of-phase information on a couple of tracks.

This could be considered fairly standard for a stereo album and normal for an Amplitude Matrix system like DY and EV-4. As will be seen later, there is no evidence of any +-90 degree information above or below the zero degree line.

Now for the next album marked QD, which is ‘Tony Mottola – The Best Of’

and its spectral phase

I’m sure that you’d agree the difference is instantly obvious, there being less ‘random’ phase information and a slightly lower level of zero phase information. But more importantly there is evidence of +90 degree information on two of the tracks.

Although it is QS encoded, due to the way the audio is encoded and this being just an overview snap shot, there is no guarantee that there will always be such marked proof as shown here. Closer examination by expanding the view horizontally per track would probably show up smaller groups of ‘information’ on either the -90 or +90 degree line.

Because of this it’s not advisable to go by just one track from an album, but at the bare minimum one half of it, preferably the whole album.

To end  i’d like to re-emphasise that this issue is probably why many state that their ‘previously thought to be EV-4 album’ decodes perfectly well through a QS decoder is because it is QS.

The program i have used is Adobe Audition 3, which was once a paid for programme but has, in the last few years, been officially available as a free download. To save having multiple links i’m making the whole package (including updates) available.

 

EV-4: The Mystery Solved?

15 May

One of the most annoying rumours that has seemingly stuck like glue with the quadraphonic community is that the AM systems DY & EV-4 are compatible with the PAM system QS.

Like a lot of these things that have become ‘accepted general knowledge’ there was a point where it all started and after 48 years, and there having been no obvious sign of anyone looking it the what, where and why’s of it, i felt it was another of the quad ‘myths’ that needed slaying once and for all.

It actually wasn’t hard to find a lead to how it all started, and for those that have a collection of ‘Project 3’ quad albums, i have a question for you.

Have a look at the record labels and you’ll probably find you have one or more where the record number ends with either: QD, SQ OR CD-4. I very much doubt anyone has a copy that actually ends in QS.

But Project 3 did release albums in QS. So what’s the deal?

As we all know, Project 3 were the only label that released many of their quad releases using one or more of the commercially available systems, many being made available in all four. So where does this leave the QS copies.

When originally sold, the system the record was in had a label stuck on the cellophane announcing which it was, but once that was removed the only way to normally tell was via the record label, and as you’ve possibly found, there are no labels with QS on them.

A simple-ish test has proven that a couple of half a dozen albums i tested were in fact QS, even though the label stated QD, the others being EV-4, as you would expect with the label stating QD.

The label originally started releasing quad albums when the EV-4 system was released and included the other systems a year or so later when they were released. It’s obvious now that instead of starting to use the QS prefix for QS encoded albums, they continued using QD, only changing when SQ came onto the scene.

I’m guessing this is where it all started. Whether it was by mistake, or some misguided idea, i believe this is soley responcible for the idea that the two systems are ‘compatible’.

This does leave those with a collection of Project 3 quad albums that are marked QD unsure whether they are EV-4 or QS. Well there is a way of telling, but it’s ever-so slightly technical, so i’ll leave it for another day to show you how to tell them apart.

 

Harmony For Elephants

15 May

Somewhat off the blogs normal course, i’d like to bring this release to the memberships attention

Harmony For Elephants

 

The re-birth of a 4DD-5

13 May

Having previously mentioned that i’ve started to (finally) modify one of my JVC CD-4 demodulators, i find the modification has turned more into something of a redesign, so whilst waiting for even more parts to arrive to allow continuation work on the main board, as well as an additional sub-board, i thought i might do a pbotographic record of how it goes.1526201814030-1128117357

Of course, whether it works or not….. Lol

Supersonic Quadraphonic Sound Spectacular EVd

10 May

Supersonic Quadraphonic Sound Spectacular EVd

Reference Series Releases contain:

Original EV-4 encoded Stereo file for personal decode evaluation (MLP only)

EVd decoded versions on MLP, DTS,AC-3

 

DY & EV-4/Stereo-4 Reference Decode Series

7 May

As part of the close-down of the blog i’ve been promising to release a small number of the demonstration records from the 1970’s for each of the major Quadraphonic matrix systems, which will include not only a decoded version of the album using the last of my decoding process’s, (the **d series) but also the original encoded stereo file on the DVD-A portion to allow comparisons between different methods of decoding that particular matrix system.

To start the ball rolling i’m starting with one of the two Amplitude Matrix system’s  (namely DY & EV-4/Stereo-4). Unlike the later systems SQ, QS etc, they were developed before the use of 90 degree phase shifting, so were quite basic and limited in what could be expected from them.

Firstly, it is/was impossible to decode the four channels back to their original positions using hardware decoders, instead the decoders were programmed to “create an effect” giving about 1db of rear left and right separation. This meant the encode and decode equations were completely different, something that didn’t happen once 90 degree phase came into use.

There has been much spoken about a QS decoders ability to actually decode the two AM systems, but that normally comes from those whose knowledge of matrix systems is either seriously limited or non-existent.

It does appear that most people are more than happy with some noise coming out of the rears, irrespective of whether it’s right or not. It’s more than likely the major reason why people believe they are hearing it as decoded is down to phase.

I’ve yet to read, or hear, of anyone who has gone near the subject, most probably because they a) have a good reason not to and/or b) they just don’t know.

So what do i mean? QS is, as i’ve previously mentioned, one of the Phase Amplitude Matrices, using +-90 degree phase shifting to enhance the encode/decode process. Of course, like anything matrix encoded, QS encoded material requires the inverse of the encode equation to be used during decoding, a part of which means the rears are shifted back to their original phase.

And here’s the rub. By attempting to decode DY or EV-4/Stereo-4 through a QS decoder, as well as being mathematically incompatible, the resulting rear channels are no longer on phase in releation to the front channels. Those who have heard the effect of out of phase speakers when setting up a stereo system will be well aware of the illusion of increased channel separation and space can becomes apparent, but that’s all it is, an aural illusion.

So, as well as making available these demonstration albums, i’m also making available a small script for those who use Adobe Audition v3 to allow correction to the rear channels to bring them back in phase with the fronts after using a hardware QS decoder.

This script is supplied ‘as is’, it makes no attempt to do any form of decoding, just correction. It is very small and ONLY for use on the rear channels of DY or EV-4/Stereo-4 material after being ‘decoded’ by a hardware QS decoder. I offer no help with this script, or in the use of it with Adobe Audition v3, or anything involved with Adobe Audition.

So, to the first of the three EV-4/Stereo-4 and one DY demonstration albums i plan to release:

Enoch Light – 4 Channel Stereo (EV-4/Stereo-4) New v2

Reference Series Releases contain:

Original EV-4 encoded Stereo file for personal decode evaluation (MLP only)

EVd decoded versions on MLP, DTS,AC-3

 

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