parts express

The nice folks at Parts Express sent over an amazing-sounding little amplifier, the $129 Topping TP30. It's a tiny desktop Class T amp design, with one analog RCA stereo input and one USB connection (the TP30 has a built-in digital-to-analog converter). The amp delivers 15 watts per channel to 4 ohm-rated speakers (10 watts into 8 ohms), and has a 3.5 mm headphone jack on the front panel.

With its extruded aluminum chassis, 8mm thick, CNC-machined front panel, and solid-metal volume control knob the TP30 wouldn't look out of place in a high-end system. It even feels expensive, but I have just one nitpick: the illuminated blue LED ring surrounding the volume control knob is too bright. I wish there was a way to dim it or turn it off. The amp measures a tidy 4.13 inches by 1.77 inches by 8.07 inches.

The USB interface utilizes standard Windows audio class 1 drivers (it worked fine with my Mac mini). Internal parts quality is superb; the TP30 boasts Elna capacitors, Dale resistors, and an ALPS volume control. The Burr-Brown USB digital-to analog converter chip accepts up to 48 kHz sampling rates with 16-bit resolution.

I compared the sound of the TP30 with my Audioengine N22 amp ($199), and they're both pretty good. The N22 has a fuller, warmer tonal balance, but the TP30 has a more immediate, detailed sound with more tightly controlled bass. I used my Audioengine P4 speakers for all of my speaker-based listening tests. It's interesting, the TP30 is a digital amp and takes digital signals "straight-in" via its USB port; the N22 is analog-only and is a more traditional Class A/B amplifier design. It sounded softer, and a wee bit less defined than the TP30.… Read more

One of my audiophile pals, Dave King, e-mailed me the other day about his latest find, the Dayton B652 ($25 per pair). It didn't arrive in time for my Top 10 audio bargains blog the other day, or it would have surely been included.

I've known Dave for 20 years, and we've listened to a lot of hi-fis together, so I know he's got great ears. And he knows how to get my attention: "I'm certain I recently discovered the absolute diminishing returns point in hi-fi loudspeakers. They remind me a lot of Wharfedale Diamond speakers of yore, but the B652 has a 6.5-inch midwoofer instead of the Diamonds' 4.5-inch." The original Diamonds were a really big deal in the 1980s; they were easily the best budget speaker of the era, but even then they were more like $60 or $70 a pair. They were probably made in England, the Dayton B652 is built in China.

It's a mid-size, black vinyl-covered monitor speaker, 11.7 inches high, 7.1 inches wide, and 6.5 inches deep. The front baffle hosts a 6.5-inch polypropylene woofer and a 0.6-inch polycarbonate ferrofluid-cooled tweeter. Dave liked the fit and finish well enough, but he wasn't too happy with the Dayton B652's spring-clip wire connectors. I agree, clip connectors never have much grip on the wires, so they can fall out when you move the speakers. I've seen those things on $100 speakers, but on a $25 speaker you can't really complain about spring clips.

One of the Dayton B652's more interesting design features is its acoustic suspension (nonported woofer. I like that because acoustic suspension woofers tend to sound better than ported ones, and Dave was impressed by the Dayton B652's bass definition. The downside to acoustic suspension designs is the bass doesn't go as deep as ported woofers do. The Dayton B652's bass is reasonably flat to 70 hertz, and Dave likes to use subwoofers with most speakers anyway. When I pressed him on the matter he said he thought most folks would be well-satisfied with the Dayton B652's bass on its own. … Read more