I have a few music tracks that are my go-to tunes when evaluating stereo systems. They’ve risen to the top not because they test different sound qualities specifically, or because they reflect any show-offy declarations of musical taste, but because they’re just great songs — ones that I’ve listened to thousands of times throughout my life. I know them intimately and can spot playback distinctions like an owl catching a flicker of movement from a mouse buried under 10 inches of snow. Plus, I never tire of them, and when I listen I focus on the delivery, not my fickle reactions to the music itself.
Auditioning the Monoprice Stereo Hybrid Tube Amp via such perennial favorites presented a special challenge. The shelf system is a 25-watt tube amp system that also has Bluetooth, so you can feed it from your smartphone or tablet. That makes it a hybrid system, using a solid-state power amplifier but a tube pre-amp. The tricky part in evaluating it is identifying what’s making the music sound so: Is it the four vacuum tubes making it sound a certain way, or the speakers and cables, or the fact that it’s streamed through the ether via Bluetooth? The only option in critical thought is to go with your gut, and the only way to find out is to fire up those tubes.
I did so in my den, a smallish room with wooden walls — about the perfect size for shelf systems. If you’re new to the idea of vacuum tubes, they predate more efficient solid-state transistor amplifiers, which are driven entirely by electrical signals, and are effectively the mechanical equivalent in terms of boosting signals and powering speakers. Though outdated by decades, they’re thought by audiophiles to generate a warmer, more realistic sound by virtue of their mechanical operation, especially when the sound is delivered via lossy Bluetooth. They give back the more subtle audio signals that Bluetooth strips away.
Having a hybrid system such as this amplifier permits modern audio sources to pair with the vacuum tube. When you turn it on, simply pair your device with the system and select your track. The tubes glow orange, as does the VU (volume unit) meter on the front. The amp looks retro, particularly with the aluminum cages protecting the vacuum tubes while showing them off. You have the option of cable inputs for audio source, and there’s a headphone jack, as well, so you’re able to control those variables as you like. (You can also upgrade the speakers.)
I cycled through my tracks and found the system to be much warmer within all of them than my go-to, and much more expensive, shelf system, the Joey Roth Ceramic Speaker and Subwoofer ($1,095). The Monoprice system did more with less, generating robust sound at high volumes through relatively small speakers, though having the subwoofer helped, too, of course. The tube amp also created a more intimate audio experience that, while not as crisp as my go-to Roth system, was exceptionally satisfying and enjoyable. And, naturally, the benefit seemed to match with the song — the more vintage Goo Goo Dolls and Queen sounded slightly better on the tube amp, while Lady Gaga and Maroon 5 tracks favored the Roth system. The Monoprice, notably, was also far better than any other Bluetooth speaker or shelf system that I can think of at this price point. I tried the same tracks in a portable BT speaker and a more mainstream shelf system, and the Monoprice’s sound was significantly better. In fact, I had to keep reminding myself that the entire system cost so little — an unbelievable bargain for such a classic experience.
Aesthetically, the amp will look great on your shelf, with its tubes, piano-black shell and silver faceplate. The build quality is solid, but not as polished as pricier vacuum tube units targeted toward the audiophile crowd. The faceplate has some rough edges, the bass and treble dials aren’t nearly as smooth-turning as higher-grade equivalents, and the illuminated VU meter looks a bit chintzy, even as it sits there bouncing happily away to the beat of “Bad Romance.” There’s also a persistent hum emanating from the Monoprice when powered on, but that’s part of the tech — and the charm. Vacuum tubes hum, and this one hums along pretty damn well.