I have some interesting findings on this front. I finally managed to acquire what appears to be a genuine QS pressing of
Permissive Polyphonics, complete with the blue sticker (for some reason this is weirdly difficult to obtain - another bidder drove the price way higher than I wanted to go). However, after spending some time A/B’ing it with my other quad copies of this album (EV-4 LP, CD-4 LP, Quad Reel), I’m not convinced that it’s QS at all - I think it’s actually the EV-4 LP simply re-packaged as QS.
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Here’s screen-grabs of the first track, “Marrakesh Express”. EV-4 on the left, QS on the right. Both were decoded using the Surround Master’s “Involve” mode. I was originally planning to use my ElectroVoice EVX-4 to decode the EV pressing, but the SM gets much more separation out of it.
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They’re pretty much identical in terms of channel separation. The only real difference I could detect between the two is that the sound quality of the QS pressing is far superior. The EV-4 pressing appears to be missing quite a bit of top end by comparison. Samples of the first 30 seconds from each source are posted below:
EV-4 LP - First 30 Seconds
QS LP - First 30 Seconds
I also have the CD-4 LP and Quad Reel of
Permissive Polyphonics, so I recorded that same track off those two sources to see how they fared. The reel is on the left, CD-4 LP on the right.
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What’s immediately evident here is that this is not the same quad mix as the EV-4/QS version. This 'alternate' mix is quite a bit more active and adventurous. On this version, the vocals suddenly jump to the left rear channel at around 2:30. This does not happen on the EV-4 and QS LPs. Another interesting difference is on the EV-4/QS mix, the synthesizer blasts at around 0:08 and 0:20 last slightly longer and pan/pulsate much faster.
To make things even more complicated, “Marrakesh Express” can also be found in quad on the
Popular Science Test Record (PR401) and the
4-Channel Stereo sampler (PR-D700), both of which received multiple releases in different quad vinyl formats. In my collection, I happen to have all three versions of
Popular Science (SQ, QS, CD-4) and the SQ pressing of
4-Channel Stereo. So I recorded in that same track off of all those sources into the same ProTools session, wondering whether which quad mix I’d get.
Top Left =
Popular Science QS (Involve Decode)
Top Right =
Popular Science CD-4
Bottom Left =
Popular Science SQ (Involve SQ Decode)
Bottom Right =
4-Channel Stereo SQ (Involve SQ Decode)
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As it turns out, they all match the alternate, more adventurous mix found on the CD-4 and reel of
Permissive Polyphonics. The QS decode from
Popular Science is remarkably similar to the discrete reel - a testament to how good the SM's QS decoding ability is.
I guess the question going forward is: for all the Project 3 titles that were issued in EV-4 and QS, are any of them genuine QS? Or are they just re-packaged EV-4?