Optoma NuForce STA200 Power Amplifier

Depth and Dimensionality Plenty

Equipment report
Solid-state power amplifiers
Optoma STA200
Optoma NuForce STA200 Power Amplifier

For the last couple of years I’ve been listening primarily to systems using switching (Class D) power amplifiers, so it was illuminating to go back to a linear solid-state design. I hesitate to make any gross generalizations, but listening through the STA200 provided a more organic and less coolly objective view of the music than most switching amplifiers I’ve used recently. Near the end of the review period, my venerable Pass Labs X150.3 power amplifier (circa 1996) was returned fully restored and updated by Pass Labs. Harmonically the STA200 had far more in common with the Pass X150.3 than any of the switching power amplifiers I use regularly. Perhaps there’s something to the idea that amplifiers that employ similar technologies share a certain intrinsic characteristic sound.

The STA200 displayed exemplary dimensionality. Lateral image placement was as precise as I’ve heard from any amplifier. Depth delineation was equal to the Pass Labs X150.3, and on some selections I felt the STA200 did a better job of defining the edges of each instrument or vocalist than the Pass could. The Bel Canto REF M600 did an even slightly better job of defining image edges and produced an even larger soundstage, but it did not better the STA200 in overall dimensionality. The REF M600 was slightly inferior in depth recreation compared to the STA200. In comparison, the REF M600’s soundstage was wider, but less deep than the STA200’s.

The STA200 had a darker than absolutely neutral harmonic balance that is quite similar to the Pass X150.3. Depending on the other components in your system you might find, as I did, that I preferred this less spotlighted upper midrange on modern pop, but on some classical and vintage jazz I preferred the Bel Canto REF M600’s slightly brighter harmonic rendering. I must stress this wasn’t a radical difference, but it was enough be readily identifiable.

One particular performance area where the STA200’s sonics were closer to those of the Bel Canto REF M600 than the Pass X150.3’s was dynamic speed and agility. Here the Pass seemed a bit less fleet. It lacked some precision in its transient attack and decay that both the REF M600 and the STA200 had little trouble traversing. Perhaps this sonic difference could be attributed to the REF M600’s and STA200’s S/N figures, which both bettered those of the Pass.

In bass control and definition the STA200 displayed a nimbleness that matched the best amplifiers I’ve heard. The bass rendition was definitely tighter and better defined in the STA200 than in the Pass X150.3, where the lower octaves were fluffier and slower by comparison. Once more I found the STA200’s basic low-frequency personality closer to that of the Bel Canto REF M600.

Currently I have the Spatial M3 Turbo SE loudspeakers set up so they receive a full-range signal with no crossover-set bass roll-off. This system also has a pair of JL Audio Fathom f112 subwoofers configured for a 45Hz, 24dB-per-octave crossover slope. Both the STA200 and the Bel Canto REF M600 generated fast, tight bass that melded well with the Fathom f112.

On my own recordings played back through my nearfield system I found the STA200 was among the more truthful amplifiers I’ve used. I did some A/B testing where I compared it with the NuForce ST-10 amplifier. I found the NuForce produced a bit larger soundstage, but it was a dead heat between the two amps in image specificity, low-level detail, dynamic contrast, and bass extension.

Basic solid-state power amplifiers are not, due to their essential nature as boxes with parts inside, sexy objects that inspire a lot of audiophile lust. Perhaps that is why so many manufacturers feel the need to tart up their basic power amplifiers with thick front panels, cool meters, or artistically sculpted, rad-colored enclosures. The STA200 will never be accused of looking sexy or especially stylish—unless you are into stark minimalism. But if sound quality and solid-state reliability are your primary purchasing criteria, the STA200 should be on your radar. You may not be blown away by the STA200’s looks, but its sound turns it into one sexy beast.

Specs & Pricing

Type: Solid-state, Class AB
Output power: 80Wpc into 8 ohms
Input: RCA analog (single-ended)
Input impedance: 51k ohms
Output impedance: 30m ohm
Dimensions: 14" x 3.4" x 8.8"
Weight: 13 lbs
Price: $1299

3178 Laurelview Ct.
Fremont, CA 94538
(510) 897-8600

Associated Equipment
Source devices: A 2013 MacPro Desktop with a 3.7GHz Quad-Core Intel Xeon E5 processor with 16GB of memory and OS 10.11.5, running iTunes 12.4 and Amarra Symphony 3.3, Pure Music 3.0.1, Audirvana+ 2.5, Roon 1.2, and Tidal 1.3.
Analog sources: VPI TNT III w/Graham 1.1 tonearm and ClearAudio Victory II cart; VPI HW-19 with Souther SLA-3 tonearm and Denon 103/van den Hul cartridge
Phono preamps: Vendetta Research SCP-2B and Vinnie Rossi LIO
DACs: Mytek Brooklyn, PS Audio DirectStream Jr. DAC, Cary Audio DMC-600SE Music Hub, Grace m9xx
Amplifiers: Bel Canto REF M600, April Music S-1 monoblocks, NuPrime ST-10, Pass Labs X150.3
Speakers: Spatial M-3 Turbo SE with two JL Audio Fathom f112 subwoofers; Audience 1+1, Role Audio Sampan FTL, Dali Opticon 1, ATC SCM7 II, with one Velodyne DD 10+ subwoofer
Cables and accessories: WireWorld Silver Starlight USB cable, WireWorld Eclipse 7 balanced interconnect, AudioQuest Carbon USB cable; AudioQuest Colorado single-ended RCA interconnect, Kimber KCAG single-ended and balanced interconnect, Audience Speaker Au24e speaker cables, PS Audio Quintet, Dectet, Octet, and Premier power conditioners