|Auditioning the KEF LS50 Black Edition, powered by SMSL SA300 Class D amp on computer workstation.|
Saturday, 17 October 2020
Saturday, 10 October 2020
Greetings everyone. It's great to interact with some of you over the years around contents I've posted in this blog. As you perhaps know, recently, I talked about resampling hi-res audio files in my article on "Post-Hi-Res" with the idea that the vast majority of albums we download as supposedly high-resolution content simply do not warrant the file size or bitrate. As such... I routinely just bring them back to 16/48 or 16/44.1.
Saturday, 3 October 2020
HOW-TO: CD Pre-Emphasis & Using SoX De-Emphasis. (And the decline of physical media with vinyl revenue > CD now.)
Have you ever ripped or downloaded an old music CD that just sounds way too harsh? Sounding like the EQ is accentuated with too much treble?
Back in the day, a number of CDs were processed with pre-emphasis used and we can see at least a partial list of pre-emphasized albums here. Typically these would be early CDs from the mid-'80s although as per the list there are also a number from the late '80s and even early '90s.
In those early years, DACs were incapable of true 16-bit resolution and noisy analogue brick-wall filters added high-frequency distortions. As a means of improving signal-to-noise, they boosted the high frequency content and corrected the tone on playback (see this Hydrogen Audio FAQ on Pre-emphasis). As you're probably aware, a CD doesn't just contain the 16/44.1 audio data but have encoded within each "frame" 8 bytes of CIRC error correction and another byte of "subcode" data which can be thought of as "control data"; like a precursor to today's much more complete metadata. One of the subcodes is the "pre-emphasis flag". When activated, a CD player will engage its "de-emphasis" circuitry/filter. These days, DAC chips themselves can implement digital de-emphasis as part of basic functionality.
Saturday, 26 September 2020
Well friends, it's time to publish some measurements of my new RME ADI-2 Pro FS R Black Edition ("FS R BE") unit as DAC. For background, refer to the Preview from August and a couple weeks back, I had published results discussing the ADC function.
As you might be aware, since 2018, I've been using the older RME ADI-2 Pro FS ("Pro FS") for ADC and DAC duties in my measurements. It has performed like a champ and in fact, given that the ADC function is almost identical between the two units, there's certainly no reason to retire the "Pro FS" from measurement duties.
What we know is that as a DAC, the "FS R BE" should perform better than the "Pro FS" due to the fact that the internal AKM chip has been upgraded to the AK4493 from the previous AK4490. On paper, this represents a +5dB improvement in SNR and +1dB improvement in THD+N so we're not looking at Earth-shattering differences in specs numbers. Let's see if we're able to measure these differences on the test bench and identify any other changes to the DAC's performance along the way...
Saturday, 19 September 2020
A Complex Path to Simple Sound
Saturday, 12 September 2020
About a month ago, I posted this preview of the RME ADI-2 Pro FS R Black Edition AD/DA converter. It has been a wonderful month of simply listening to this device without a care around performing measurements. For listening, I have it set up as per the image in my sound room with the Raspberry Pi "Touch" running RoPieee previously discussed.
So far, from a subjective perspective, it has been a joy to listen to music with this machine.
Alas, as a "more objective" audiophile, it came time to have a look at the performance for this device to check if I'm missing any significant limitations. Over the years, I've discussed limitations to human hearing as well as the idea that many of our audio electronics these days have surpassed human auditory perception such that while measurements of DACs or amplifiers can show limitations, often these are beyond the resolution thresholds of human hearing/perception. Remember that while not all measurable anomalies need to be chased after when the goal is simply to be able to enjoy music, technical "ideals" are useful for devices one may want to use as a "reference".
So to start, today let's just focus on the ADC side of this RME device. Remember that the RME ADI-2 Pro FS R Black Edition (again, let me just call it the "FS R BE" for short) is an evolutionary step from the ADI-2 Pro FS ("Pro FS") that I started using 2 years ago. Consider this article as building on some of what we already know about the Pro FS as an ADC from 2018 with requisite repeated tests comparing the two machines and using today's software.
Saturday, 29 August 2020
SUMMER MUSINGS: Modern Tech Life; obligatory home computer mechanic - NVMe replacement, WiFi Router. And thoughts about "high end", high priced DACs and value (Recent Darko & Sircom).
I was actually planning to just take a little break this week but given that it's almost September, I'll be away for Labour Day and school's starting for the kids with likely some virtual elements, I thought I'd just pen a not-too-long post not so much about audio but rather the highly computer-dependent world we're living in (with a bit about audiophile stuff to end).
Saturday, 22 August 2020
SUMMER MUSINGS: The Soundroom - speaker layout, vibration control & correction. (And importance for the subjective reviewer!)
I thought before summer's over, it was time to "shoot the breeze" again and talk generally about a very important topic that affects all of us audio enthusiasts with what I hope are some practical suggestions from my own "journey" here at home.
The image above of a room set-up came from an article back in 1960 entitled Room Acoustics for Stereo by Abraham B. Cohen (Electronics World, January 1960 - make sure to also check out Part 2 here from February 1960). This was a time when many homes were still transitioning from the monophonic single-channel era to the bold new world of stereophonic "3D" playback with an opportunity to virtually experience an actual soundstage in the comforts of the living room. Those must have been exciting times, perhaps comparable in my lifetime to the late '90s with the release of AC3/DTS receivers providing discrete multichannel home theater.
As you can see from the pair of articles, already back in 1960, the groundwork had been laid out for what constitutes conditions for good "stereorama" sound. Best practice tips to achieve a sense of realism, the variables related to speaker placement in a room, angles to target for from the sweet-spot, distance between speakers and orientation like toe-in. Room characteristics like absorption characteristics of materials, reverberation time, room layout were discussed as well; all this informed by decades of professional recordings and studio design that came before.
Saturday, 15 August 2020
Saturday, 8 August 2020
DIY: Raspberry Pi "Touch" Audio Streamer (2020) and RoPieee - US$160. Spectral tilt, educational articles, and anti-audiophoolery...
It has been awhile since I built my Raspberry Pi "Touch" Streamer discussed back in 2017. We're here now in 2020 and I had the need to put another one together. Since 2017, I've been using Roon more than Logitech Media Server (LMS) in my sound room so I thought I'd focus on installing RoPieee for this article although piCorePlayer remains my preferred software for LMS use (I still have LMS running on a Linux VM on my Server machine for remote playback of music away from home).
Raspberry Pi 3 B+ - $42
AC Adapter 5V/3A with switch (microUSB for Pi 3) - $10
Official Raspberry 7" touchscreen - $64
SmartiPi Touch 2 case - $30
SanDisk 64GB microSD - $13
RoPieee software - donation-ware download, your choice "standard" or "XL"
Saturday, 1 August 2020
Look what showed up at my door (finally!) the other day. This is the latest hardware update to the RME ADI-2 Pro line of converters, the RME ADI-2 Pro FS R "Black Edition" - quite the mouthful! Let's just use "FS R BE" for the rest of this article for short in reference to the name.
Currently, the street price is around US$2,000.
Back in mid January, RME debuted this latest iteration of the ADI-2 Pro at NAMM 2020. Since 2018, I have been in contact with Matthias Carstens (co-founder of RME) off and on about the ADI-2 Pro FS that I have been using for measurements on this blog. Shortly after NAMM, I contacted Matthias about getting an upgrade as I could use two of these ADI-2 Pro devices - one for the soundroom and another for my test bench - when the company starts shipping these.
Saturday, 25 July 2020
SUMMER MUSINGS: Post Hi-Res Audio. Why hi-res is often not for the best. Resampling, dithering and de-clipping.
It has been a good summer around here thus far with time off, working around the house, and of course time to enjoy the warm weather for a bit. Here in Vancouver, the late fall to early springs are typically dark and rainy so I'm happy to catch a few photons when I can :-).
With the pandemic, this will certainly be an unusual summer/year. Unless things change substantially, this will be the first year in 2 decades that I won't be traveling off the continent for vacation or work - heck, I can't even visit the USA at this point without at least 2 weeks of self-quarantine back in Canada. In that spirit of staying put and cleaning up this year, I thought I'd talk about a few related items that have been on my mind pertaining to my music library.
A few months ago, I wrote an article about remembering that for home audio, we must always think about the big picture triad of PRODUCTION - REPRODUCTION - PERCEPTION. So often, we in audiophilia spend disproportionate amounts of time on the hardware aspects of reproduction (what's new? how do these devices measure/perform?), or speak of subjective perceptual experiences. Much of that I think is a reflection of what our magazines, online sources, and forum topics revolve around. Maybe that's what the Industry also wants us to think/talk about. We so often forget that in fact, a huge amount of what we perceive - or can perceive - has already been "baked into the cake" from when favourite recordings left the studio (or perhaps specifically the mastering engineer's workstation).