seldom reviews A/V receivers. We made an exception for Arcam's FMJ SR250 ($3600) because it's that unusual two-channel device: one that includes room-correction software, in this case Dirac Live. Many of us who listen in multichannel are comfortable with room correction, but a week doesn't pass without my hearing or reading someone say that they bypass room correction when listening to music in stereo. Spock-like, I find that illogical and, from experience, pointless.

If one accepts that, just like careful speaker positioning and acoustic treatments, room equalization exists to correct for the corruption of sound imposed by room reflections and modes, then using it for a stereo pair of speakers is no different from using it for the same speakers in the same positions when they are only the front L/R pair of a multichannel array. The interactions among speakers, room, and listener are exactly the same.

Objections can be raised. Some say that inserting DSP into the signal path compromises the sound, but in fact, no physical devices need be addedthe resident DSP, already necessary for converting and decoding digital signals, simply uses a different algorithm to pass the signal(s) along. If you play vinyl, yes, DSP does mean more hardware in the signal path; you have to decide for yourself, hopefully without bias, whether or not the improvements in sound performance outweigh any degradation by the conversions and DSP.

Although the FMJ SR250 has but two main channels and two switchable subwoofer outputs, that it is an audio-visual receiver is apparent from the fact that it has the same user manual as Arcam's multichannel AVRs. However, like many modern stereo integrated amps, it has analog inputs and outputs and a power-amp stage, and supports digital inputs and streaming sources (though it lacks WiFi). It also has FM and DAB tuners, and HDMI inputs and outputsthe music lover can also use it for watching TV and movies.

A brief run in New York City

I unpacked the FMJ SR250 in my Manhattan apartment and hooked it up to my front left and right speakers, Bowers & Wilkins 802 D3s, which aren't too difficult to drive but have a reputation for loving power and for being very revealing. Source signals were stereo analog and S/PDIF from my main preamp and server, respectively. The SR250 handled all with aplomb, which didn't surprise menot only had I naïvely assumed from its model number that its specified power output was 250Wpc, but the Arcam is big and heavy enough to sustain the illusion, measuring 17.1" wide by 6.7" high by 16.7" deep and weighing 33.3 lbs.

I've been auditioning with the B&Ws a series of power amps, with power-output specs ranging from 200 to 500Wpc and prices from $1200 to $12,000. The SR250 fit right in with that company. When I at last read the fine print, I learned that the SR250 is specified to output 90Wpc in class-G. For those new to class-G, Arcam's website provides a good explanation. John Atkinson summed it up well in his favorable review of Arcam's FMJ P49 power amplifier in the November 2015 issue:

"The output stages are operated in class-G, meaning that there are actually two pairs of positive and negative voltage rails feeding the output transistors. These transistors are usually powered from ±35V rails, but when the input signal voltage would lead to clippingat around 50W into 8 ohms MOSFET 'lifters' switch to ±65V rails, allowing the signal to be amplified by the same devices up to the specified 200W without clipping. (These lifters are said to be capable of turning on and off with as much as 60A peak current in less than a microsecond.) Class-G allows the power supply to be more economically designed, as the higher voltage rails have only to be able to supply current for a fraction of the signal's duty cycle, the lower voltage rails supplying the bulk of the continuous current demanded by the loudspeakers.

"A superficial reading of Arcam's literature suggests that the output devices are biased into class-A. But with an 8 ohm load, that would mean a standing current of 1.75A for each channel and a very hot-running amplifier, even if the heatsinks were much larger. Closer reading reveals that the output circuit "includes a proprietary error-correction circuit that modulates the modest standing currents in the output stage and ensures a near-constant output impedance for peak currents of up to about ±4 amps, corresponding to well over 50W into 8 ohms. The P49 thus behaves exactly like a classical class-A amplifier up to this power level in terms of performance but without the heat penalty."

The SR250's performance in my Manhattan system was proof that its two analog class-G power amps were quite powerful. From the diaphanous to the monumental, the SR250 did well with all types of music, though I didn't hear quite as much soundstage detail as I do with the bigger, more expensive amps. I wasn't cruelI didn't try to push the Arcam beyond what I asked of the othersbut the overall sound was equally smooth and unfatiguing. This was very encouraging; I was unlikely to lean on it so heavily in Connecticut, where I have Monitor Audio Silver 8 speakers in a smaller room.