The Sprout100 is a small integrated amplifier made by the Colorado company PS Audio. One chassis combines stereo amplification, digital conversion, an MM phono input stage, a headphone output and a wireless receiver. It is aimed at desktop and small living room systems where a single unit has to replace several separates, and the casework is offered with real walnut side panels.
Key specs that matter
Output is 50 W per channel into 8 ohm and 100 W per channel into 4 ohm. The headphone output delivers 500 mW into 32 ohm and 125 mW into 300 ohm. Conversion uses an ESS Sabre 9016 chip that accepts PCM up to 24 bit and 384 kHz and DSD up to DSD128. PS Audio rates the noise floor at better than 84 dB, with THD plus noise held under 0.01%. The chassis measures 15.7 cm wide, 4.8 cm high and 20.8 cm deep, and the unit weighs 1.3 kg.
Engineering and use context
Inputs include asynchronous USB Type-B for a laptop or desktop computer, an optical digital socket, a moving magnet phono input on RCA, a stereo RCA line input and Bluetooth wireless. There is no coaxial digital input, so a CD transport with only a coaxial output needs a converter or an optical connection. Bluetooth lets a phone or tablet stream to the amplifier without cables. On the output side the Sprout100 has a stereo RCA line output, a dedicated subwoofer output and a front headphone jack. The line output lets the unit work as a preamplifier for a larger external power amplifier, which gives an upgrade path without discarding the Sprout. A remote control is supplied. Because the amplifier, converter and phono stage share one enclosure, the only cables needed in a basic system are the speaker leads, a power lead and the source connections. The small footprint allows it to sit beside a monitor or on a shelf where a full width component would not fit.
Pairing
Compact bookshelf speakers or desktop monitors in a room of about 20 m2 match the power available, and a powered subwoofer connected to the dedicated sub socket can extend bass below what small woofers reach. A vinyl player using an MM pickup can be wired to the phono socket as is, while a moving coil cartridge needs a step-up device first.
Alternatives
The PS Audio Stellar Strata is a bigger PS Audio integrated that also includes a DAC, with an MM and MC phono section added in the later Strata MK2 version.