1. I programmed an automatic playlist generator, now called "mplay" (but possibly renamed for distribution so as not to be confused with other things with same name). I am now planning to "release" it to the public within a few months, I just barely started thinking about a release package in the last week of 2021. It is likely to be useful only to computer geeks like me who like music.
This has made programming background music from my wonderful album collection a snap. It also means my vast collection (800 albums and more being added all the time) is actually being used, and not just my top 10 favorite albums.
I was working on this on and off during 2021. In the last week of 2021 I finally got around to fixing some major bugs. It actually works as intended now, I think, for the most part. Previously it had a tendency to keep getting stuck (and never finishing), ignoring all my latest albums (which I hadn't realized), and repeating the same things far more than intended (which I long suspected, but I worried would it be hard to figure out and fix, but in fact only took a few hours of concentrated effort).
I never thought I would do such a thing. I now wonder how I ever got along without it. Why did I bother collecting so many albums I hardly ever actually played?
2. Improving the home automation control of the living room stereo. I already bragged about this last year, but the job had not been finished. I added home automation control of the Oppo (just in time for use by mplay generated playlists). Considerable work was also done making the programming and reprogramming the home control system to make control of the audio system more convenient.
3. Keeping the local Classical Music FM station sounding good. Twice this year KPAC developed audio problems. I reported them and they got fixed. The first time, the problems didn't get fixed for months. The second time, in late December, they got the problem fixed in less than a week after I reported it, and I even got a friendly call from the station engineer. The audio problems were identical on both FM and streaming. The station engineer said it was a network problem.
4. Tracking down a peculiar distortion problem. I figured out that sometimes Sonos attempts to add digital gain when it shouldn't. A Sonos Update appears to have fixed the problem. But I mostly use the Oppo nowadays anyway, except for testing, and when I do testing I'll be aware that this issue could pop up again, though I'm taking some measures (like not fiddling with the volume change buttons on the Sonos Node) to prevent it. This problem might or might not affect some earlier results, such as the miniDSP seeming to need 6dB extra headroom. I will be aware of that next time I do serious testing.
5. Fixing a low level buzz. I discovered I had a buzz about -55dB from normal levels, or -80dB from peak levels. This was fixed by cutting the shield and ground pin on the AES digital cable feeding the Emotiva DAC. Funny I had just written a post arguing that audiophiles shouldn't be much concerned about -110dB distortion potentially being added by jitter or other digital anomalies, while often ignoring -60dB noise and distortion. It turned out that I was yet another person ignoring a -60dB noise. The fact that this made no difference when I was comparing Hafler and Krell a few years ago suggests that if you can't hear a noise at the listening position, it probably doesn't matter much.
6. Testing and adding a new digital recorder. My biggest audio purchase this year was a brand new Tascam DA-3000 digital recorder, for making digital transcriptions of vinyl records and FM radio. I tested this to be certain it is bit perfect when used with the Lavry AD10 analog to digital converter, and with a clock cable. Without the clock cable, it is not quite bit perfect. Unlike my previous recorder, the Marantz PMD-580, the DA-3000 allows the Sample Rate Converter to be turned off, so I am recording the exact bits produced by the Lavry. I've already recorded a bunch of Sheffield direct-to-disc and Reference Recordings vinyl albums.
7. Switching to XLD (X Lossless Decoder) for copying CD's to my harddrive. Up until last year I had always used iTunes for copying. But iTunes does not always produce perfect copies, and I was becoming disturbed by the errors from some CD's I had acquired from an estate sale. XLD uses the Accuraterip database to ensure accurate rips. I also find it easier to use since I can place files into a folder of my own choosing. Before settling on XLD I also tried Poweramp CD ripper, but I didn't like it as much.
8. Over 100 albums have been added to my harddrive, including new transcriptions from vinyl. There are many hundreds more where those came from.
9. I now use Audacity's "repair" effect to remove pops from vinyl transcriptions.
10. Minor adjustments to the EQ since the last system crossover and EQ tuning work in 2020. I itended to do much more work but never got around to it. Anyway, the system sounds great, far better than anything I've ever had, mostly thanks to earlier work.
11. Reworked how my Sonos nodes in living room and kitchen are connected. I'm back to having two nodes in the living room, one dedicated to making HDCD decoding through the Denon DVD-9000. I have a labeled switch in the Kitchen which determine which kitchen source plays thought the Sonos Line in. Previously it seemed that always the wrong thing was connected and it was hard to change. I changed to unshielded CAT6a cables for the Living Room nodes, eliminating another possible source of hum (as compared with using the shielded cables).
12. Oppo now connected through Ethernet (with unshielded Cat6a cable). I hadn't even realized I had the Oppo on wifi only. That possibly explained a few (but very few) previously inexplicable dropouts.
13. Upgraded my computer CD/DVD drive to a metal cased Other World Computing unit. My old LG DVD drive started having problems.
14. Leveled the turntable stand. This required removing all the equipment from the stand--no easy job--and adjusting the feet on the stand to make it level, then putting everything back. Previously I hadn't trusted the "wobbly" feet on the stand. But once the stand is on it's feet, the wobble goes away.
15. Read the Linn LP12 Setup Manual. I am hoping to get my LP12, whose suspension started becoming very erratic in late 2021 (probably after I wrongly but briefly flipped the turntable on edge) fixed soon. But after trying unsuccessfully to fix it myself, I read the LP12 Setup Manual so I have some basic understanding. I hope to have my LP12 expert, Mark, over here soon to fix and, and now I'll have a better idea of what he is doing. I tried, unsuccessfully so far, to order a Linn Setup Jig from England. I obtained a Linn Spindle Oil Cap from a Linn Dealer in USA. (It's a black OEM one that the dealer claimed to hold tighter than the red original.)
16. Discovered the source of occasional audio distortion in the bedroom system. It turns out that I have sometimes set the audio level on the Mac to way over 100% by mistake...this is done simply by moving the scroll wheel while the mouse is over a VLT window.
17. Got an actual SanDisk interface for reading Compact Flash cards. This works about 100 times faster than the old Compact Flash reader I had from the 1990's (built into a floppy drive...). What had been taking 6 hours is now done in 6 minutes.
18. Copied all my Reference Recordings HRx high resolution discs to my harddrive. I didn't even realize until recently that I could do this. These are some of my favorite recordings, and now they are much more accessible as well as being available to my playlist generator.
19. Labeled all the Surround controls on my Kitchen system. I use two chifi preamplifiers and two Behringer DEQ's to adjust surround sound on the Kitchen system, and I could never remember which box or control did what. Now they are all labeled.
20. Verified acoustic response to 39kHz using M50. I had a vast array of microphones and systems for measuring up to 40kHz. Unfortunately, none of them were functioning completely, including my Mighty Mike, which needs a new capsule. I need to create an usual adapter cable for my Bruel and Kjaer SPL meter which could properly power a few B&K capsules I have, but I've never gotten around to it.
So, in at least a second major purchase in 2021, I purchased my long time dream, an Earthworks M50. I measured my system using that and my previous standard, a Dayton mike calibrated to 25kHz and compared the measurements.
It turns out my Dayton mike was essentially showing the correct response, with a few minor corrections in the very high end.
The HF curve is: a dip to 17khz, a peak above 20kHz (the Dayton was showing that peak a bit lower than actual) and ultimately a steep decline in the upper 30's, but not going below the 17kHz level until 39kHz. (The M50 shows about 4dB more response at 39kHz than the Dayton.)
I think a curve like this is fairly inevitable without a different supertweeter technology, such as my old ELAC 4pi, which could possibly be used now that I can create very steep phase linear crossovers.
Interestingly many of the highly regarded tweeters have peaks like mine in the 20-30kHz region. Lousy tweeters have peaks in the 10-20kHz region, or steeply rolled off response at 15kHz. The HF peak helps mitigate the loss of angular dispersion at the high end of a dome tweeter.
Of course, I do use a highly regarded cloth dome tweeter, I think one of (if not "the") best ever made for supertweeter usage, the Dynaudio D21AF, which the manufacturer rated to 40 kHz. I only wish I'd bought a bunch more of these in the mid 1980's when I had the chance.
But the magic is also in my crossovers, etc.
Dynaudio's response curve doesn't show any peaks, however. I think that's because it's an anechoic on-axis measurement.
Setbacks
1. The Linn LP12 developed a terrible suspension wiggle. I hope to have this fixed soon, but meanwhile I've been using the Mitsubishi LT-30, which isn't too bad I think, and this has also given me the opportunity to make transcriptions of 45 RPM records, which especially includes the ones from Reference Recordings. I should also be fixing some of my other turntables.
2. One of the two Emotiva Stealth DC Dacs used for amplifiers powering the Acoustat speakers failed. This means I can no longer do A/B amplifier comparisons without changing cables. I also hope to get this fixed soon.
Conclusion
Overall another excellent year for playing music and doing Audio Investigations and Improvements!
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