VSX-82TXS Measurements & Analysis

The Pioneer VSX-82TXS houses a 690VA Transformer, two 10,000uF 71V caps which is a fairly robust power supply for a receiver in this price class. 60V caps would have been sufficient to yield 130wpc power figure this receiver boasts, but its nice to see they have some design margin which ensures the caps will never be in an over voltage situation even if the voltage fluctuates dramatically during a high line condition. Taking this receiver apart was a bit of a pain thanks to its 21 chassis screws. I was starting to think this receiver was HEMP hardened to withstand a nuclear pulse.

Preamp

The preamp section was able to accommodate up to 4Vrms in and deliver up to 7Vrms out into a 100 ohm load without clipping or distortion. This is a much higher voltage than will ever be seen in real world audio signals and indicates this receiver will mate well with a variety of power amplifiers if more power is needed.

SNR Tests

I was mildly disappointed with the higher than average SNR measurements I got from this receiver. With 200mV in and 1 watt out, I was able to achieve 76.8dBv (unweighted) which is about 6dB worse than I've seen on similar priced receivers from Yamaha or Denon. With the power section bypassed, the preamp delivered a slightly better SNR (78dBv) as expected. If you mate this receiver with high efficient speakers in close proximity to the listening position, you may detect a slight audible hiss during low passages.

Amplifier Efficiency

Amplifier Efficiency Measurements for linear a/b amps such as the ones employed in this receiver typically range from 40-50% depending on the load the power supply of the amplifier sees. The closer you get to full load, the higher the efficiency usually becomes (assuming you aren't over taxing the power supply and power devices of the amp causing excessive thermal losses). The Pioneer VSX-82TXS achieved around 50% efficiency which was quite impressive for a receiver employing a conventional linear amp design.

Note: All power output figures above were conducted at 1kHz and 0.1% THD + N

Power Bandwidth

The Pioneer VSX-82TXS possesses a wide bandwidth amplifier topology with a -3dB point in excess of 85kHz.

At full continuous unclipped power (166wpc x 1; 8 ohms, 138wpc x 2; 8 ohms - full bandwidth with less than 0.1% THD+N), the Pioneer VSX-82TXS still maintained good bandwidth linearity with a -3dB point of 51kHz despite we were driving the receiver way beyond its rated 130wpc power specification. Into 4 ohms, the VSX-82TXS was able to deliver continuous power levels at a whopping 235wpc x 1 and 190wpc x 2 with less than 0.1% THD + N. The amplifier section of this receiver is conservatively rated. Kudos to Pioneer.

Keep in mind most review publications don't do continuous power measurements and they usually publish power measurements into clipping at 1% THD + N. Our measurements are very conservative and it is clear that this receiver is a true workhorse for its asking price.

For more info on amplifier measurements, see: The All Channels Driven (ACD) Test

FFT Distortion Analysis

At 1 watt into 8 ohms, the PA350B exhibited impressively low distortion (8.82+ 60.009)dBv = 68.83dBV or 100*alog^-1(-68.83/20) = .04% THD + N which is clean as expected but not as stellar as similarly priced units we've tested in the past including the budget Yamaha RX-V659.

(29.964 + 40.251)dBv = 70.22dBv or 100*alog^-1(-70.22/20) = .03% THD + N which is still quite good and indicative that this receiver can deliver more juice beyond its power rating.

Amplifier Output Impedance & Damping Factor

The amplifier output impedance was around 150mohms (a bit higher than our desirable 100mohm or less mark) for the entire audible bandwidth up to 10kHz with sharp increase above at the upper 20kHz frequency range. This is good performance for an A/V receiver though not quite as stellar as we've seen in similarly priced units from the likes of Denon and Yamaha.

The amplifier damping factor is about what I expected based on the measured output impedance. It is uniformly good across the entire audio frequency range just barely meets our 50 mark for an 8 ohm load we like to see as a minimal requirement for receivers. All in all, it's a good measurement and this receiver will likely be able to consistently drive a wide range of loudspeakers with good results. We do suggest sticking with speakers that don't dip below 3 ohms for best results.