Yamaha A-S701 Stereo Amplifier Review

[JeremyFife]

Many thanks for another interesting review.

Surprisingly hard to vote - illustrating how pointless it is to try to boil a review down to a single measure!
Looks like a very nice Amp indeed. Perhaps having the additional features of DAC and phono (however niche) measured would help describe the full capabilities of this as an Integrated amp, rather than just the power amp section.

Are we spoiled / expectations skewed by very high SINAD figures now?
Is that giving us an unrealistic view of what an amplifier should do? This has power, it's pretty much load and frequency independent (within practical limits), better than audible dynamic range and it looks awesome. Minor question over crosstalk.
The DAS is probably transparent, hopefully the headphone stage is good and the phono stage is probably fine too. That's a lot
It's a tried and tested design too, reliability is likely to be good

What am I trying to say? I voted "fair", it's probably much better than that.

 

[JSmith]

The same board with the same PCB color and the same large tin bars are found in Yamaha integrateds from the 1990s...

I guess the Yamaha philosophy is "if it 'aint broke, don't fix it".

Bottom picture is from a different model (AS501?)

Apologies, you're correct, I quickly scanned that old thread whilst busy.


JSmith

 

[MCH]

Had the AS-500 for several years. Unfortunately I prefer to avoid such big devices nowadays.
I remember the feel of the knobs was excellent, I wonder if in part related to their slightly "cone like" shape.

 

[ObjectiveSubjectivist]

@amirm Any chance to get Sabnaj A30a measurements?

 

[GDWL34]

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.
View attachment 375866
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:

View attachment 375867
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:
View attachment 375868
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:
View attachment 375869
View attachment 375870
Noise performance is excellent at 5 watts and nearly so at full power:
View attachment 375871
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:
View attachment 375872

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:
View attachment 375874

Lack of much rise in distortion at higher frequencies translates into excellent performance in the 19 & 20 KHz intermodulation distortion test:
View attachment 375875

I wish crosstalk was better:
View attachment 375876

The amplifier is rated at 100 watts into 8 ohm and it nicely delivers that and then some:
View attachment 375877

It nicely scales to 4 ohm:
View attachment 375878
View attachment 375879

We can see the nice predictable power as we step through frequencies:
View attachment 375882
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:
View attachment 375880

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:
View attachment 375883
It doesn't quite double down on each impedance half but it still produces a ton of power:

View attachment 375884

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.

Conclusions
The Yamaha A-S701 is a beautiful integrated amplifier with a lot of functionality. Its design is very robust and is cable 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.

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/

This really is the sweetspot in the Yamaha range. Still enjoy my R-N803D.

 

[Guddu]

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.
View attachment 375866
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:

View attachment 375867
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:
View attachment 375868
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:
View attachment 375869
View attachment 375870
Noise performance is excellent at 5 watts and nearly so at full power:
View attachment 375871
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:
View attachment 375872

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:
View attachment 375874

Lack of much rise in distortion at higher frequencies translates into excellent performance in the 19 & 20 KHz intermodulation distortion test:
View attachment 375875

I wish crosstalk was better:
View attachment 375876

The amplifier is rated at 100 watts into 8 ohm and it nicely delivers that and then some:
View attachment 375877

It nicely scales to 4 ohm:
View attachment 375878
View attachment 375879

We can see the nice predictable power as we step through frequencies:
View attachment 375882
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:
View attachment 375880

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:
View attachment 375883
It doesn't quite double down on each impedance half but it still produces a ton of power:

View attachment 375884

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.

Conclusions
The Yamaha A-S701 is a beautiful integrated amplifier with a lot of functionality. Its design is very robust and is cable 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.

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/

As usual….. Thank you @amirm

Could you tell anything on thermal performance?

and Yes, +1 to votes for its DAC testing please!

 

[early rejecter]

I likely would’ve replaced one of my aging integrateds with one of these if only Yamaha (along with most others) hadn’t dropped the tape monitor function. Obviously few people are monitoring recordings these days, but it’s so handy for slotting in a DSP or syncing up streamers. I wish some sort of equivalent was still commonplace.

 

[Scytales]

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:
View attachment 375869

Questions :

Is it relevant to mix integrated amplifiers and power amplifiers tested without a preamplifier in the same chart ?

Shouldn't the two types of devices been separated in order to make relevant comparison ?

When testing integrated amplifiers, the noise and distortion contribution of the preamplifier stages (even passive ones) inevitably leaves their imprint on the measured performances.

 

[restorer-john]

Must be some crusty old engineer still designing these, seeing all those jumpers to avoid having a 2-sided PC Board!

Love those crusty old guys. When stuff vaporizes, we can fix it.

 

[restorer-john]

@amirm One thing to bear in mind, and to perhaps test, is the input overload on line level inputs on these Yamahas (they all use the same input IC). They will not in my experience tolerate your high level inputs without serious distortion. I note you've tested at 245mV and an arbitrary 1.6V??

About 2.2V to 2.4V is the limit.

 

[silentt29]

It sounds like the audio has come from heaven, with all kinds of veils lifted... you will ascend to a state of ecstasy.


JSmith

You can hear the lifted veils from the kitchen.

 

[silentt29]

Thank you for the review! I've been happily using the R-S501 for a few years now, which I believe is very similar to the R-S701, albeit with less power and lacking a CD Direct Amp function.

 

[Mikig]

great amplifier.
Not only in appearance, I find the entire Yamaha range captivating, but as we can see from the test, also in performance.

I like the amplifier with "large" dimensions: it gives the possibility to better manage all the cables, in order, that are necessary in the system.
The price seems more than reasonable to me for the category and the objective performance it offers.

I think it can be a worthy listening companion for systems of all categories, considering that it can apparently handle even slightly fussy speakers.

Thanks Amirm as always for the time spent and for the review.

 

[peng]

Very decent test bench performance, but I am sure the A-S700 that does not have any AVR ICs in it like the 701/801 do, would have likely measured a little better on Amir's test bench. And, don't forget the R-N803 that's just a receiver, but also performed well on the bench!

 

[aedagnino]

"Yes the controls are plastic unlike the glory days when they were metal. But the feel is good, if a bit light."
You can always change the knobs! Loads to find on aliexpress, eBay, amazon, etc...

 

[leighhull72]

Should I ditch my Fosi V3 and SU1 and get this then….or am I wasting £500

 

[pma]

@amirm One thing to bear in mind, and to perhaps test, is the input overload on line level inputs on these Yamahas (they all use the same input IC). They will not in my experience tolerate your high level inputs without serious distortion. I note you've tested at 245mV and an arbitrary 1.6V??

About 2.2V to 2.4V is the limit.

Agreed!

 

[JeremyFife]

Should I ditch my Fosi V3 and SU1 and get this then….or am I wasting £500

It won't sound any different ... you'll get different features and one much bigger box (which is either a good thing or not, that's up to you) ... if your speakers are very tricky to drive then you might be able to play louder with less distortion but that's probably not a real world issue.

In general, be happy with what you have - relax and enjoy the music

 

[Sak]

Thanks for review.
love my amp. Although my model is a little different - A-S700.
Looks the same. Only the knobs are still metal, not plastic. I wonder what else is different.

 

[JRG]

I have the S501 which is essentially the same amp with less power and I think it’s a great amp. Could be great if you can measure the phono input too.
Thanks for this review.