Saturday, 25 April 2020

MEASUREMENTS: Soditer "Fourth Generation" USB Type-C Headphone Adaptor (Realtek ALC4042).

These days, many recent smartphones no longer include analogue headphone jacks. Implicitly, the idea is to favor wireless Bluetooth headphones instead. As a result, if you want to hook up your wired headphones, one would need to buy a headphone adaptor which may come with your phone (for example, Apple at the beginning included their Lightning to 3.5mm Headphone Adaptor and these days may include some Lightning EarPods).

Recently, I upgraded my phone to the Huawei P30 Pro which does not have headphone output, so I was in the market to get one of these for the phone's USB Type-C digital connector.

Many of these headphone out / DACs are inexpensive, and the adaptor I have here today - the Soditer USB Type-C Headphone Adaptor - ~US$25, is advertised as supporting hi-res playback (even up to 32/384), and is claimed to provide up to 35mW into 32Ω headphones. Let's have a look...

Saturday, 18 April 2020

MEASUREMENTS: Roland Mobile UA-M10 DAC (PCM, 1-bit, 4-channel, Balanced Out)

Roland UA-M10. Note colorful level LED, 2 volume buttons, 2x3.5mm outputs; the one on the right labeled "A", and the one to the left where I have a cable connected "B".
In late 2019 when I visited my friend one afternoon, he showed me an interesting DAC he owns. It's the Roland Mobile UA-M10. This device has been on the market for awhile (since around late 2015), it's also a little more expensive than most small-form-factor, USB-powered DACs out there these days at around US$200-250.

Physically, it's a small, light, aluminum box with two volume buttons up top and a bright LED indicator that dances with the music when playing. The bottom surface has a couple of rubber strips across the length of the box that protects from scratching whatever surface you're putting it on - nice touch. Like many other USB DACs these days, it's completely powered by the micro-USB 5V input. The heart of this box is the AKM AK4414EQ DAC which interestingly is a 4-channel DAC (see datasheet). The device makes use of this by having both a headphone out phono plug on one end plus a line out phono output on the other, each of which could be playing independent content. The driver has the ability to tell the DAC which mode it should operate in.

Saturday, 11 April 2020

MEASUREMENTS: NB Cables "The Vigilante", Raymond Cables, Canare 4S11, Slinkylinks Silver Speaker Cables. (And related thoughts on audiophile "snake oil".)

Continuing on from the investigations into LCR parameters for speaker cables started a few weeks ago, today, let's have a look at a few more cables with the REED Instruments R5001 (remember there are limitations of course but comparisons can still be made across cables). As you can see in the previous article, the cables I measured were zip-cord types compared to my DIY "Colorful Speaker Cable". Today, let's look at commercial speaker cable offerings and check out some numbers for each.

Among the cables in the montage above, notice that I do have a more "exotic" cable, the silver conductor, Slinkylinks Biwire with gold banana plugs (asking price back in the early 2010 for 4m/13' was NZ$1840 = ~US$1100 today). As with last time, let's go through the measurements one by one, ending off with those Slinklinks.

Sunday, 5 April 2020

MUSINGS: COVID-19 mortality, age distribution, underlying health conditions and hope beyond...

As I publish this, it's April 5, 2020. We are in the midst of the coronavirus/SARS-COV-2/COVID-19 pandemic. The world is afraid. Borders are shut. Stores are closed. Concerns with crime increasing as a sign of social stress and perhaps distress.

We're also at a bit of a loss in terms of leadership through this. Again, speaking from a North American perspective, there is no "vision" of what the future might hold or any talk as far as I am aware of plans to relax restrictions. If anything, it's the opposite, an atmosphere of rule by fear with threats of further shutdowns. As I expressed in the second half of March, we are in a state of fear, with "abundance of caution" being as good a catchphrase as any of what's happening here; uniformly expressed among governments and public health experts.

In all this, let's look at some statistics and think about this more, shall we?

Saturday, 4 April 2020

REVIEW: Optimal Audio and Video Reproduction at Home (Vincent Verdult, 2019)

For those reading this blog, I think I've been quite consistent over the years in expressing my views about audio/visual technology. I think my philosophy around the importance of focusing on the objective and being careful with purely subjective evaluation has been clear.

As such, once awhile when I am contacted to consider a new product or asked to provide an opinion, I will of course evaluate through that perspective.

A couple months back, I was contacted by Vincent Verdult to have a look at a book he recently published by Focal Press, succinctly titled Optimal Audio and Video Reproduction at Home, released in 2019. I was sent the 346 page paperback from the publisher, it's also available in hardcover and eBook editions. Let's spend some time with the contents of this book and consider how one might find it helpful especially as an audiophile.