Saturday, 21 November 2020

On "Measurements, Listening, and What Matters in Audio" by Robert E. Greene, with unfortunate Robert Harley "counterpoint".

It has been a busy week, so alas, I didn't get a chance to finish some recent measurements in time for the weekend. Will aim for next week!

The other day, I read Robert E. Greene's editorial on The Absolute Sound's webpage titled "Measurements, Listening, and What Matters in Audio". Nice, I didn't think I would ever read such coherent introspection in those (virtual) pages. Probably also one of the first times I have seen the mainstream audio press willing to consider the "beginning of audio wisdom" (hat tip to Proverbs). Of course, seeking wisdom plus achieving a more rational basis in this hobby are overarching themes in many of the articles on this blog. So too, Greene's reference to concentrating on the "fundamentals", the foundation of acoustics whether it be in the production chain (ie. "microphones") or the reproduction/perception system (ie. especially "speakers and their room interactions") are not unfamiliar to readers here - we covered some of this earlier this year. Absolutely agree, Dr. Greene, including the part about "I think that almost everything in audio can be explained by measurements" is a fair and in these days, a very safe statement to make.

Wishing you good health.

Now as for Robert Harley's "counterpoint". Oh my... Surely Harley's ramblings cannot be the last words on this topic because clearly there are issues!

Saturday, 14 November 2020

MEASUREMENTS: S.M.S.L. SA300 - Infineon MERUS-based Class D desktop amplifier. (Screwed up New York Times - Wirecutter/Butterworth measurements/review?! And Klipsch on TIM.)

"BAS" on screen indicates I'm using the bass-boost EQ here.

Today, let's have a look at the little SMSL SA300 desktop amplifier I'm showing above sitting beside the Topping DX3 Pro V2 DAC (previously measured and reviewed here).

As mentioned previously, I found myself in the position of needing to update my computer workstation desktop speaker system. I figured, instead of staying with powered/active speakers, since I do have a few bookshelf speakers around the home, why not try some passives on the desktop as well?

While active speakers are great in that the built-in amplifiers and transducers can be well-matched and optimized, the ability to "mix-n-match" passive speakers while opening up the potential to upgrade amplifiers I think is fun for the hobbyist. As such, I found myself drawn to getting a small low-power Class D amplifier like this.

Since the amplifier will likely be left on 24/7, I wanted something that's highly efficient but provides adequate power. This SMSL device internally is powered by the Infineon Technologies MERUS MA12070 Class D amplifier which uses their "multi-level" modulation such that the switching output can have half-voltage levels which adds an extra level of control and power savings. The device is rated to provide up to 2x30W continuous into 8Ω or 2x80W into 4Ω but realize this is with 10% THD+N. What will be more interesting to me is how much power is available into something like 4Ω with ≤0.1% THD+N, and the noise this switching device produces. Let's see if this amp lives up to hopes of "high-fidelity" playback...