A little surprised at the absence of the bottom octaves, I queued up Holly Cole’s album Temptation (DSD64/DSF, Acoustic Sounds). The track “Invitation to the Blues” opened with tons of bass power and detail. So what happened on “Folia Rodrigo Martinez”? Well, while there’s lots of bass on the Holly Cole album, it’s not as deep as the bass on “Folio Rodrigo Martinez”. In the midrange, Cole’s voice caressed the superbly recorded songs with rich harmonics and delicate vocal nuances—a real hi-fi showcase which contradicts the urban audio legend that excellent performances are invariably poorly recorded.
At the risk of overdoing female vocalists (is that possible?), I queued up Rebecca Pidgeon’s The Raven (176.4/24 FLAC, Chesky/HDTracks, remastering by Bob Katz). On “Kalerka,” Pidgeon’s soprano exhibited a bit of sibilance I’ve not often heard before on this recording. Throughout, the album sounded a smidgen overemphasized in the upper midrange, though still very clean and detailed.
I wanted to check how music via Bluetooth compared to music from a wired computer connection, so I ripped the CD La Folia, 1490-1701 in AIF format to my iPhone and played “Folia: Rodrigo Martinez 1490” over Bluetooth. I cranked the volume setting on the iPhone’s Music app to maximum and adjusted the headphone’s output with the PMA-50’s volume control until the PMA-50’s Bluetooth gain was compatible with the iPhone’s Bluetooth gain. Through the Bluetooth connection, everything sounded very clean; however, the highs were a bit overemphasized. I should note that although I tried the Bluetooth connection after the amplifier had broken in, I didn’t make a special effort to break in the Bluetooth connection itself. I don’t know if that would have made a difference, but I couldn’t live without my phone long enough to give it a try. Wait—did I just admit I can’t live without my iPhone? How sad.
Sound with Speakers
I didn’t expect a lot of bass from the Soliloquy speakers’ 5¼" mid/woofers. Often, speakers designed to work well with an SET’s low damping factor sound lean and thin driven by solid-state amplifiers, which tend to have fairly high damping factors. So I was pleasantly surprised when I heard robust, powerful bass from the PMA-50 with the Soliloquies. In particular, the low end on “Invitation to the Blues” was more powerful than expected, with lots of detail. Holly Cole’s vocals were quite clearly defined, and highs were smooth but extended.
As expected, through loudspeakers “Shenandoah” showed more dimensionality. There actually was a decent soundstage! The tonality of de Grassi’s guitar was rich and full. On another song on this album, I was startled when de Grassi whacked the body of his guitar—great transient response! Since the Soliloquy speakers were easy to drive, the PMA-50 never came close to clipping. Unless you try driving low-sensitivity speakers quite loudly, I suspect the PMA-50 will work fine in a small room.
I didn’t have a classic integrated amplifier to compare to the PMA-50, so I used another type of integrated amp, the Light Harmonic Geek Out 450. Reviewed in Issue 251, the Geek Out sees daily use driving a variety of headphones in my office computer system. J. River Media Center version 20.0.63 is the music playback software I use with the Geek Out via its supplied 6" USB cable. Like the PMA-50, the Geek Out includes a DAC and a headphone amplifier, but not a power amplifier to drive speakers.
Starting with “Folia: Rodrigo Martinez 1490,” transients created by the percussion instruments really snapped. High frequencies were extended but not peaky. For a headphone amplifier, the Geek Out 450 really has a surprisingly good soundstage. It doesn’t compete with speakers, of course, but for headphone listening it’s pretty remarkable. Bass was powerful and extended. Only a few other headphone amps have produced deeper low end.