AV Receiver Reviews

Two channels driven continuously into 8-ohm loads:
0.1% distortion at 114.1 watts
1% distortion at 134.1 watts

Five channels driven continuously into 8-ohm loads:
0.1% distortion at 80.2 watts
1% distortion at 95.6 watts

Seven channels driven continuously into 8-ohm loads:
0.1% distortion at 77.3 watts
1% distortion at 90.4 watts

Analog frequency response in Direct mode:
–0.02 dB at 10 Hz
–0.01 dB at 20 Hz
–0.10 dB at 20 kHz
–3.12 dB at 50 kHz.

Analog frequency response with signal processing:
–0.10 dB at 10 Hz
–0.03 dB at 20 Hz
–0.41 dB at 20 kHz
–67.31 dB at 50 kHz.

This graph shows that the TX-NR636’s left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1% distortion at 114.1 watts and 1% distortion at 134.1 watts. Into 4 ohms, the amplifier reaches 0.1% distortion at 187.9 watts and 1% distortion at 215.0 watts.

There was no multichannel input to measure. THD+N from the CD input to the speaker output was less than 0.006% at 1 kHz when driving 2.83 volts into an 8-ohm load. Crosstalk at 1 kHz driving 2.83 volts into an 8-ohm load was –70.30 dB left to right and –79.45 dB right to left. The signal-to-noise ratio with an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –110.26 dBrA.

From the Dolby Digital input to the loudspeaker output, the left channel measures –0.01 dB at 20 Hz and –0.31 dB at 20 kHz. The center channel measures –0.01 dB at 20 Hz and –0.29 dB at 20 kHz, and the left surround channel measures –0.01 dB at 20 Hz and –0.29 dB at 20 kHz. From the Dolby Digital input to the line-level output, the LFE channel is +0.07 dB at 20 Hz when referenced to the level at 40 Hz and reaches the upper 3-dB down point at 96 Hz and the upper 6-dB down point at 107 Hz —Mark J. Peterson

Video
The Onkyo passed all of our standard video tests, whether it output the source as 1080p or upconverted it to 3840 x 2160 (consumer 4K). While it did pass the MA standard-definition (480i) upconversion test, the result was smoother on motion when the Onkyo upconverted the 480i source to 1080p and let the set (a 4K Samsung here) perform the final step of the upconversion (1080p to 4K). (The rating here is based only on the upconversion to 1080p.) If you own or plan to buy a 4K set, always compare the upconversion in the set to any outboard 4K upconversion (in a disc player, AVR, or pre/pro). If you see no visible difference, we recommend using the upconversion in the set.

While it does pass 3D, the Onkyo will not upconvert 3D sources to 4K—but neither will other AVRs we have tested into a 4K set. —Thomas J. Norton