LISTENING: Fully battery-powered wireless streamer & amplifier system (Yeeco - TI TPA3116D2, TalentCell 12V battery)

A few weeks ago, I read this review on an independent audiophile site about an inexpensive Nobsound Class D amplifier based on the TI TPA3116 chip. I was curious so I ordered an equivalent one off Amazon - the little Yeeco Bluetooth-capable amplifier shown above with box contents including the 12V power supply for <$US32 (for an even cheaper package, here's one without the switching power supply, <US$25).

As you can see, the reviewer linked above gave the product some positive comments on the sound. I was curious to listen and since we know that Class D amps like these are very efficient, how about we run the playback system - music streamer to amp to speakers - completely wirelessly and battery powered for a listen also?

MUSINGS and LISTENING: On Absolute Polarity / Phase... (And on the joy of the modern audiophile.)

Hey guys and gals, I thought for this post we'll spend a bit more time on the topic of "absolute polarity". As you can see from the post last week in the comments, our man in Japan Yamamoto2002 posted a link to his page where he has an interesting test signal for all to listen to.

If we look at the test signal he used, it's an asymmetrical waveform where half of it appears to be a standard sine wave, the other half has been "flattened" off which results in numerous harmonics if we are to display it on an FFT. One of the files is simply the inverted version of the other to test whether this polarity change is audible. Notice that the waveform is bandwidth limited, and there is no "ringing" after going through a digital filter.

MEASUREMENTS: Topping D10 DAC. (And a few words on "absolute polarity / phase".)

Hey guys, getting busy around here as I'm preparing for summer holidays coming up in a couple of weeks :-).

I did want to post a "quick" report however on the Topping D10 DAC (<US$90) I got last week... It's for an upcoming project of sorts which I'll post on over the months ahead. What I wanted was a DAC that could be powered off USB, reliable with Window and Linux compatibility, that's reasonably portable, and of course of high signal accuracy.

Notice the DAC manual shows some AP measurement graphs... I guess Topping believes in showing objective accuracy :-). Nice.

GUEST POST: Why We Should Use Software Volume Control / Management by Bennet Ng. (Plus discussions on resampling options, true peaks, etc...)

I received an invitation from Archimago to write something about volume control. While I am of the opinion that digital and analog volume controls can coexist to achieve an ideal gain stage, this article is mainly about PCM digital volume control.

The basic conclusion we can say regarding digital volume control is that as long as the playback device has higher bit-depth than the file source, it is possible to losslessly reduce the volume of a file until the playback device's bit-depth limit is reached. For example, with an ideal 24-bit device, it is possible to playback a 16-bit file 48dB lower without losing quality, because one bit has about 6dB of dynamic range (the exact formula of bitdepth and dynamic range is 6.02*n-bits + 1.76).

POLL RESULTS: Music streaming service adoption among audiophiles in 2019...

Click on image to zoom.

Yeah, I know. Music streaming as a subscription model is the latest "revolution" for music lovers. This is why I decided to put up the recent poll in mid-March while we were concurrently also running the blind test as reported on in the last few weeks. Above, you see the overall results based on the visitors to this blog.

Remember that for the poll, I allowed voters to select up to 3 options. As a result, even though there were 616 respondents, a total of 809 selections were made. This means that up to ~30% of people selected more than 1 option and these are represented in the percentages above.