On Home Theater Review's companion site, Audiophile Review, I've often covered entry-level portable audio components and the question of how portable audio aficionados can migrate to room-based systems (or even if they will). And while there are lots of bargain-basement-priced low-power integrated amps, as well as a plethora of four- and even five-figure integrated amplifiers for big-boy systems, finding a great-sounding integrated amplifier with enough power, inputs, and outputs to put together a serious starter-priced high-performance audio system has been more of a challenge. Cue the music; enter the PS Audio Sprout100 ($599 MSRP).
The Sprout100 is the new, improved version of the original PS Audio Sprout. It doubles the rated output of the previous one from 50 watts to 100 watts per channel into 4 ohms. The new Sprout100 also adds a nifty remote, boosts PCM capabilities from 192/24 to 384/24, and adds DSD capabilities up to DSD128. Bluetooth sources run natively into the Sprout100's ESS Sabre 9016 DAC chip.
The Sprout's dimensions are almost as tiny as its name: just 6 by 8 by 1.75 inches. It can handle five different sources: vinyl, analog line level, digital via USB, digital via Toslink, and wireless Bluetooth. The vinyl input has 40 dB of gain and supports moving magnet cartridges with outputs between 3 and 10 mV with 47 kilohm loading. The analog input can handle a maximum input level of 2.1 VRMS and has 10 kilohm input impedance. The USB and Toslink digital inputs share the same "digital" source setting, and if you want to use Toslink, the USB input must not be active. The Bluetooth uses an internal antenna, so there's nothing external to connect.
The Sprout100's outputs include one pair of speaker connections that use a banana-type connection. PS Audio supplies four adapters, though, so you can use spade lugs, bare wire, or even a bi-wire connection. The Sprout 100 also has a single subwoofer output, as well as a pair of stereo RCA line-level outputs.
The built-in headphone amplifier features a new discrete "zero impedance Z-feedback" circuit that PS audio claims can "drive virtually any pair of headphones you can throw at it with perfect transient impulse response." This improvement is due primarily to the headphone amplifier's high slew rate of 1300 volts/microsecond, which is 100 times faster than the previous Sprout's headphone design.
Bluetooth comes in many varieties with different codecs. The Sprout100 uses Bluetooth 2.0 with no additional aptX or LDAC compression/resolution enhancements. According to PS Audio, they tried including aptX but found that the coverage range and overall fidelity were no better for the added cost and complexity, so they opted for plain vanilla BT 2.0.
Controls on the Sprout 100 are about as simple as they can get. The front panel has two knobs; one is a volume control, the second is the source selection. The only two additional features on the front panel are the quarter-inch headphone connection and a small LED light in the upper right-hand corner. This LED's color changes depending on the Sprout100's current settings. Red is protection mode (which you hopefully will never see), white indicates the bass-boost function is active, blue means the bass boost is turned off, and dim blue or white is mute mode.
The bass boost was easily the most controversial feature on the original Sprout since it could not be turned off. On the Sprout100 you have the option of turning it off one of two ways: when you connect a subwoofer to the subwoofer output the Sprout100 automatically senses it and turns off the bass boost. You can also manually toggle the boost by pushing in the volume control for a long press, and the light will change from white to blue (or vice versa).
The Sprout 100's compact remote may not be adorned with bells, whistles, and flashing lights, but it has the essential controls laid out in an elegant minimalist fashion. The remote lets you turn the Sprout100 on and off, mute, and adjust the volume up or down. If you want to change the source you will have to get off your duff and turn the source selector on the Sprout100's front panel. Remember, though: exercise is good for you. One more detail: I suppose that the remote has a replaceable battery but finding out how to replace it looks challenging since there is no obvious battery compartment or screws to unscrew anywhere on the unit.
Click over to Page Two for Performance, The Downside, Comparison & Competition, and Conclusion...