Do you really need a DAC that costs between $14,000 and $18,000? Bluebird Music thinks the Jadis Vacuum Tube JS5 or JS2 SL ...

The Spark 2 from Positive Grid looks like a miniature old-school amp, but it is, essentially, a computer with some knobs and a speaker. It has Bluetooth, USB-C, and an associated smartphone app.

The Diablo 333 amplifier is a fine example of the breed. It is the pricier of the company’s two integrated options, and sits in an extensive range that includes almost every part of the audio chain.