STR-DA7100ES Measurements and Conclusion
Benchmark Measurements and Analysis
We measured the Sony STR-DA7100ES' output impedance vs. frequency at 1W. It stays relatively flat across the bandpass, but does increase dramatically starting around 15Hz and 15kHz. This is a higher than typical output impedance then we are accustomed to seeing, but not surprising given the amplifier topology (a side effect of the LPF of the output stage). Care should be taken however to mate this receiver with a speaker that has a relatively constant impedance profile to avoid frequency response variations or inconsistency in sound.
The damping factor of the receiver was pretty consistent at around 20, dipping down significantly around 50kHz. Again this is lower than typically seen on receivers with linear amps in this price class.
Measuring attenuation versus frequency, we can see the Sony starts to show some gain at just over 20kHz which then drops off as the analog toroidal low pass filters kick in above that point. On the low frequency side we're looking at a really flat response with a gentle roll off below 100Hz (we're talking about 1/4 dB) with a steep fall off below 20Hz.
Wanting to get in a quick power measurement before we had to pack up the unit for Sony, we measured Max unclipped power into 8-ohms and showed that the Sony could easily drive a single channel from 40Hz to 20kHz at around 183 watts (20Hz was showing 162 watts).
At 1Vrms input to the Sony, the output is 2.67Vrms before the receiver limits the output to avoid clipping. This indicated that the Sony STR-DA7100ES' preamplifier outputs can drive most power amplifiers we are aware of to their maximum potential. Max input voltage before clipping was 2.188Vrms at which point Vout at the preamplifier was measured at 5.89V.
All power tests were done with all testing equipment and the receiver plugged into a voltage regulated APC S-15 and S-BATT unit.
Conclusions and Overall Perceptions
Sony is a company with a long and rich history in the electronics market. We were happy to finally take an in-depth look at their new receiver line. It's got plenty of power and enough features to keep most people satisfied. It misses on the finer details like on-the-fly and input level trims, but jumps all over new technologies like HDMI upconversion and video processing. I'd love to see Sony take some additional American input on their user interfaces and remote control design. We also recognize, though, that so often these types of products are integrated into home automation systems (or at the very least incorporated into the functions of a universal remote control) that many of its targeted users may not take much notice in these areas. Overall this is a nice receiver - both in terms of its build quality and looks and well as its ability to satisfy in the performance department.
The Score Card
The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:
Performance × Price Factor/Value = Rating
Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.
Audioholics Rating Scale
— Excellent
- — Very Good
- — Good
- — Fair
- — Poor
| Metric | Rating |
|---|---|
| Frequency Response Linearity | |
| SNR | |
| Output Impedance | |
| Measured Power (8-ohms) | |
| Multi-channel Audio Performance | |
| Two-channel Audio Performance | |
| Video Processing | |
| Bass Management | |
| Build Quality | |
| Fit and Finish | |
| Ergonomics & Usability | |
| Ease of Setup | |
| Features | |
| Remote Control | |
| Performance | |
| Value | |
