overall impedance supplied by Newport Test Labs), I eventually concluded that if you are using just a single pair of speakers with the A-S700, you should set the impedance selector to the ‘high’ position, even if the label on the rear of the speaker says ‘4Ω’. It is only if you have connected TWO pairs of speakers to the A-S700, and will be using the A+B mode regularly that I would recommend using the ‘Low’ position. (I know this is somewhat at odds with Yamaha’s recommendation, but I think Yamaha is playing it super-safe.) As a result of my investigations, all my listening sessions were conducted with the A-S700’s impedance switch set to the ‘High’ position.
The A-S700 proved to be very powerful, as it was easily able to over-power even the largest and most inefficient speakers I had available, in the process creating louder sound pressure levels than most people will ever need. The A-S700 is so powerful, in fact, that even with inefficient speakers in a large room I don’t think you’ll ever be hungering after more power than it can deliver. It really is an amazingly powerful amp! Even when you’re not running it full tilt (and you won’t be), the power that is available on tap means that the bass is really solid and well-defined, so that there is a real sense of authority in the lowest frequencies. More importantly, even if there’s a lot going on in the bass region, the power available means that there are no unwanted modulations of the very highest frequencies, so the treble sound is as pure as it is when there’s very little happening down low. But the bass isn’t just big, it’s also so rhythmic and bouncy that you don’t even start to question pace and timing: they’re right there… vibrant and on the go.
Midrange sound is crystal-clear and beautifully transparent. There’s a lovely sense of clarity and ‘ease of listening’ that comes through at all times… though it is particularly obvious when auditioning lighter works that are heavy on human voice and just a few higher-pitched instruments (think typical ‘demo track’ at any hi-fishow). However, extended auditioning with complex orchestral and/or choral works will show that even when presented with such sonic difficulties, the sound of the Yamaha AS700 doesn’t ever become compressed, or even congested, so that it’s very easy to appreciate the multiple threads that are usually woven by composers, as well as the professionalism of the musicians in teasing out those threads into a performance.
The air around the high-frequencies is a joy. Individual notes seem to suspend themselves just long enough to allow you to enjoy the harmonic relationships with what lies below, yet not hang around so long that they confuse the issue by extending into unrelated multi-layered puffery. Sonic purity was at the highest level.
What you certainly won’t hear from the Yamaha A-S700 is any unwanted electronic noise, because Yamaha’s engineers have excelled themselves. There is absolutely no background circuit noise or hum at all. And, although I could hear tiny differences between the ‘normal’ mode and the two direct modes when music was playing, I couldn’t hear any differences at all in noise levels between the three when no music was playing, even when the volume level was advanced. This ultralow noise capability, combined with the high power output level, and the speed with which the amplifier was able to respond to even the fastest transients, meant that the overall sound is highly dynamic, which in turn gave musical performances the lift they need to propel them to the upper levels of the reproduced sound stakes.
I can unhesitatingly recommend Yamaha’s AS700 to anyone who’s after superior sound reproduction from an integrated amplifier, not just because of its sound quality and overall performance, but also because Yamaha has such a great reputation for its product quality and its customer support… in the unlikely event that you’ll ever need it, which I doubt you ever will.
Yamaha A-S700 Integrated Amplifier
Category: Integrated Amplifier
Warranty: Two Years
Distributor: Yamaha Music Australia Pty Ltd
High power output Whisper-quiet noise levels Lovely sound balance
Speaker terminals Remote only comes in silver Front panel marks easily