Top positive review
5.0 out of 5 starsGreat sound quality, and correct audio polarity
Reviewed in the United States on April 10, 2019
rev 6/1/20
This CD is apparently based on a modern DSD or high-res digital copy of the same analog master which has been used for various CD-releases, including the 1986 and 1994 releases. The 1986 release was apparently made with a 1st-generation digital deck with Apogee aftermarket input filters. Apogee filters were popular among recording engineers for their superior detail, spaciousness and imaging compared to the stock filters. The 1994 release was apparently made with an early commercial oversampling A-to-D converter, which didn't need complex input filters and probably had 20-bit linearity. I prefer the earlier releases, but only the 2016 release is available as reasonably-priced new CD's. Used CD's are always a gamble since you might get one that looks like it was used as a coaster. But if you buy a used version, you could buy the 2016 release to pay the record company its due.
In case you wonder what I'm using as a player, it's a $100 2017 Nobsound Bluetooth 4.2 Lossless Player, which I gave five stars on Amazon in 2018 and which can handle anything a CD can throw at it. I assume that it's even more amazing with high-res source material, but it's not worth it to me to improve audio beyond what the Nobsound can extract from CD's. Recording engineers need extreme resolution to keep their mixes clean, but it's not necessary just for listening.
Not many people seem to care about audio polarity, but they should because they would probably discover that some of the CD's which they consider to be mediocre just have the wrong polarity and are actually phenomenal with the right polarity. Identifying the correct audio polarity is just a matter of using a good player and listening to the CD when you're in the mood to hear it, so that you're more intent on hearing it and more likely to hear subtle details, and less likely to hear nonexistent problems. You would alternate between the two polarities (such as by listening to one of your favorite tracks for a while with one polarity, and then with the other polarity) until the differences become apparent, or until you get tired of it, in which case you would stop and continue the next time you're in the mood to hear it. (Sometimes it can take a while for the truth about a CD to break through mental blocks caused by your beliefs about how it sounds.) A polarity control would help to speed up this process by allowing you to flip the polarity a bunch of times while playing a passage which is particularly sensitive to polarity, and by eliminating all variables except polarity.
Quite a few CD's, including some very popular ones, have the wrong polarity, and some of these, such as Steely Dan's Alive In America, some (or perhaps all) versions of Pat Metheny Group, and the single-CD version of Steven Wilson's Aqualung remix, don't just sound better, but become much more transparent and alive when the polarity is corrected. (The Pat Metheny Group SHM-CD has the wrong polarity, which could be corrected, but it's also slightly sped up, which ruined the CD for me. I suspect that it was sped up in a misguided attempt to compensate for the lifelessness caused by the polarity error.) I've tried both polarities of the 2016 Animals CD (which has the right polarity), and it definitely sounds better with the right polarity, but I wouldn't call it a stunning improvement.
How to change audio polarity
As far as I've been able to determine, the only new consumer gear with polarity controls consists of a few high-end preamps, such as those by Audio Research (each of which has an Invert button on its front panel, and I assume on its remote control). However, there are a couple of alternative approaches. One is to invert .wav's or FLAC's with an audio editor. Another is to flip the polarity of each speaker connection, which you could do with switches as explained below:
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WARNING
If you add a polarity switch in line with each speaker cable, as described below, do not flip the polarity at high volume levels, or you might damage your amplifier or speakers.
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An example of a simple polarity control is a DPDT light/wall switch with cross-connected throws (throw A+ to throw B-, throw A- to throw B+) in line with each speaker connection - apply the input across the poles and take the output from across the throws, or vice versa. Wall switches and suitable enclosures (plastic outlet/switch boxes) are readily available, and the switches have screw terminals and hefty switch contacts.
For solid connections, solder wire terminals on the speaker cables, and on the cross-connecting wires. Actually, one end of the cross-connect should share a terminal with the speaker cable, to ensure the best connection between the speaker cable and the cross-connect. I would avoid using the push-in terminals on the back of the switch because a good connection requires a combination of large surface area and oxygen-free metal-to-metal contact (almost a like a spot-weld), the latter of which requires wiping under high pressure. (This is why I recommend daisy-chaining the cross-connects onto the speaker cable - otherwise, there would be two wire terminals on each screw terminal where a speaker cable and a cross-connect meet, and the bottom terminal wouldn't be subjected to wiping as the screw is tightened, which would compromise its connections to the switch and to the other terminal.) Gold is ideal for audio connections, but a sufficient connection can also be obtained with a screw terminal screwed down on a wire terminal as tightly as possible without stripping the screw.
Polarity control for balanced connections
If you're lucky enough to have components with balanced (differential) connections, you could create an interconnect with a line-level version of the polarity switch described above. However, the same warning applies - before flipping the polarity, mute the audio signal before it gets to the polarity switch, or immediately after the switch, or you might damage your system.
