This is a review and detailed measurements of the Yamaha A-S701 stereo integrated amplifier with included DAC and Phono stage. It is on kind loan from a member and costs US $800.
The A-S701 is one of the best looking amplifiers I have tested. Yes the controls are plastic unlike the glory days when they were metal. But the feel is good, if a bit light. Here is the back side:
I left the "impedance" switch at default high. In AVRs if you select 4 ohm, it will actually power limit to pass regulatory testing for excess heat. I am behind in testing this amplifier so focused on the amplification stage and not the DAC or Phono. If I get time and owner can wait, I can test those as well.
Yamaha A-S701 Integrated Amplifier Measurements
As usual we start with our 5 watt dashboard after setting the volume control to get 25 dB gain:
This is better than I expect, landing the A-S701 in the upper range of our "very good" rating category as far as noise and distortion:
Noise performance is excellent at 5 watts and nearly so at full power:
Testing is done with CD direct unless otherwise noted. As you see above and manual states, it produces best performance. You lose all the controls though if you turn it on.
Frequency response is nice and flat in audible band:
For kicks, I tested the loudness response as you see above. I have never used an amp with variable loudness. The ones with switches made things louder, not less loud.
Multitone performance is respectable, sans the power supply noise:
Lack of much rise in distortion at higher frequencies translates into excellent performance in the 19 & 20 KHz intermodulation distortion test:
I wish crosstalk was better:
The amplifier is rated at 100 watts into 8 ohm and it nicely delivers that and then some:
It nicely scales to 4 ohm:
We can see the nice predictable power as we step through frequencies:
I think this is the first amplifier I have tested which doesn't cheat out on 20 Hz test signal.
The amplifier is essentially open for business on power up:
Amplifier Reactive Load Stress Tests
Let's use the loadbox to simulate resistive and non-resistive peak power going all the way down to 2 ohms:
It doesn't quite double down on each impedance half but it still produces a ton of power:
Keep in mind that these are stereo tests so total power is twice as much. Very nice.
I should note that the amplifier handled overloads during this test as if they were not there. No protection. No powering down. No nothing.
EDIT: DAC and Phono Input Measurements.
Yamaha A-S701 Digital Input Measurements
Unfortunately there is no pre-out so I can only test digital input when going through the amplifier. Then again, that is how you would use it. Here is our dashboard then with Toslink input:
Well, this is sad. Distortion spikes fair bit reducing SINAD by some 8 dB.
We also lose 6 dB in noise department:
Yamaha A-S701 Phono Input Measurements
Per above, this is again with amplifier engaged:
We are dominated by the amplified power supply noise which I could not further reduce.
RIAA equalization is not the greatest, losing bass response by 1 dB @ 20 Hz:
I would have thought Japanese companies know how to do a phono stage cold. Doesn't seem like it especially when one sees the early overload:
Conclusions
The Yamaha A-S701 is a beautiful integrated amplifier with a lot of functionality. Its design is very robust and is capable of easily exceeding its specifications. Overall ranking is at the high-end of "very good," bordering on excellent. All of this comes at a reasonable cost.
EDIT: both the DAC and phono stage are mediocre.
I am going to recommend the Yamaha A-S701 stereo integrated amplifier. If you are a fan of traditional class AB amplifier and you want something that looks good to boot, the A-S701 seems to be the ticket.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The A-S701 is one of the best looking amplifiers I have tested. Yes the controls are plastic unlike the glory days when they were metal. But the feel is good, if a bit light. Here is the back side:
I left the "impedance" switch at default high. In AVRs if you select 4 ohm, it will actually power limit to pass regulatory testing for excess heat. I am behind in testing this amplifier so focused on the amplification stage and not the DAC or Phono. If I get time and owner can wait, I can test those as well.
Yamaha A-S701 Integrated Amplifier Measurements
As usual we start with our 5 watt dashboard after setting the volume control to get 25 dB gain:
This is better than I expect, landing the A-S701 in the upper range of our "very good" rating category as far as noise and distortion:
Noise performance is excellent at 5 watts and nearly so at full power:
Testing is done with CD direct unless otherwise noted. As you see above and manual states, it produces best performance. You lose all the controls though if you turn it on.
Frequency response is nice and flat in audible band:
For kicks, I tested the loudness response as you see above. I have never used an amp with variable loudness. The ones with switches made things louder, not less loud.
Multitone performance is respectable, sans the power supply noise:
Lack of much rise in distortion at higher frequencies translates into excellent performance in the 19 & 20 KHz intermodulation distortion test:
I wish crosstalk was better:
The amplifier is rated at 100 watts into 8 ohm and it nicely delivers that and then some:
It nicely scales to 4 ohm:
We can see the nice predictable power as we step through frequencies:
I think this is the first amplifier I have tested which doesn't cheat out on 20 Hz test signal.
The amplifier is essentially open for business on power up:
Amplifier Reactive Load Stress Tests
Let's use the loadbox to simulate resistive and non-resistive peak power going all the way down to 2 ohms:
It doesn't quite double down on each impedance half but it still produces a ton of power:
Keep in mind that these are stereo tests so total power is twice as much. Very nice.
I should note that the amplifier handled overloads during this test as if they were not there. No protection. No powering down. No nothing.
EDIT: DAC and Phono Input Measurements.
Yamaha A-S701 Digital Input Measurements
Unfortunately there is no pre-out so I can only test digital input when going through the amplifier. Then again, that is how you would use it. Here is our dashboard then with Toslink input:
Well, this is sad. Distortion spikes fair bit reducing SINAD by some 8 dB.
We also lose 6 dB in noise department:Yamaha A-S701 Phono Input Measurements
Per above, this is again with amplifier engaged:
We are dominated by the amplified power supply noise which I could not further reduce.
RIAA equalization is not the greatest, losing bass response by 1 dB @ 20 Hz:
I would have thought Japanese companies know how to do a phono stage cold. Doesn't seem like it especially when one sees the early overload:
Conclusions
The Yamaha A-S701 is a beautiful integrated amplifier with a lot of functionality. Its design is very robust and is capable of easily exceeding its specifications. Overall ranking is at the high-end of "very good," bordering on excellent. All of this comes at a reasonable cost.
EDIT: both the DAC and phono stage are mediocre.
I am going to recommend the Yamaha A-S701 stereo integrated amplifier. If you are a fan of traditional class AB amplifier and you want something that looks good to boot, the A-S701 seems to be the ticket.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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