- Written by Stephen Hornbrook
- Published on 22 September 2011
The Pioneer VSX-1021K 7.1 A/V Receiver On The Bench
The 1021 did ok on our video processor tests, passing the Overscan, Whiter-Than-White, Blacker-Than-Black, Luma Multi-burst and Luma plate tests. However, the Pioneer failed the Chroma Multi-burst and plate tests when the source is set to either YCbCr 4:2:2 or YCbCr 4:4:4. Setting the Pioneer's video convert mode to off will solve these issues as long as you are using HDMI as the input. In order to convert analog video signals to HDMI, video convert must be enabled. Just be sure to set your Blu-ray player to RGB mode for the best picture quality when running video convert mode. For any sort of resolution scaling, like 720p/1080i sent from a cable box, video convert mode must be turned on.
For the audio bench tests, we used the CD input and set it to Pure Direct mode to bypass all internal processing. Although the VSX-1021 is not rated for 4 ohm loads, we went ahead and tested them anyways.
At 6 dBV with a 1 kHz test tone, the Pioneer has 0.156% THD+N with an 8-ohm, load and it moves up to 0.2% with a 4-ohm load. The entire spectrum is filled with even and odd harmonics as well, with the peaks measuring around 60 dBV below our test tone.
Increasing the power to 15 dBV, the 8 ohm number drops to 0.054%, and the 4 ohm load drops to 0.046% THD+N. The excessive harmonics continue here as well.
With a 10 kHz test tone and a 4-ohm load and 6dBv we got 0.03% THD+N and on the 8-ohm load we got 0.016%.
Moving the voltage up to 10 dBV, the 8-ohm number moves down a bit to 0.012%. For the 4-ohm load we bumped the voltage up to 12dBv and got 0.025%. Again the secondary harmonic peaks around -70 dBV.
With both 4-ohm and 8-ohm loads at 2V of output, we see significant harmonics from the amplifier, and the B-A peak is present on the 4-ohm load, but is not nearly as large as other peaks at 18 kHz and 21 kHz. There is curiously no B-A peak at all on the 8-ohm load, but still some very high harmonic noise. The Pioneer has at most 60 dBV of headroom here.
Increasing the voltage we see the same performance, with lots of harmonics and 60 dBV of headroom.
On the IMD test with 60 Hz and 7 kHz tones, the 4-ohm load is once again much better than 8-ohm, measuring 0.067% versus the 8 ohm's 0.31%. There is a second order harmonic at 14kHz that leaves around 60 dBV of headroom with the 8-ohm load and 70 dBV with the 4-ohm load.
When we move up to 8 dBV, the IMD for 4-ohm goes to 0.056% and with 15dBV on 8-ohm we get 0.12%. The second order harmonic remains the same as the previous test.
Looking at the THD+N vs. Frequency graphs, the 4-ohm load is fairly even across the board, staying between 0.04-0.05% with a steep drop right around 10 kHz to 0.005%. However, with the 8-ohm load the Pioneer hovers above 0.2% for most of the spectrum, and then once again has a steep drop down to 0.005%. This helps to explain why the 1 kHz test showed so many harmonics yet the 10 kHz test was relatively clean in comparison. The random peak at 1.5 kHz on the 8-ohm load can be ignored, as that's a random testing glitch.