This didn’t last though. Even before the Kuro program was wrapped up, Pioneer returned to stereo with a range of amplifiers and SACD players in the A and D series that looked a little curious but had sonic performance that suggested that the company was taking stereo seriously again. Ironically, the range that has replaced these amps is nothing like as futuristic in appearance at their predecessors but what they lack in swoopiness, they make up for in what is going on inside.
The A-70 integrated amplifier you see here is the flagship stereo amplifier in the range and costs a not insignificant £800. Behind that figure is a very flexible piece of equipment. Pioneer has designed the A-70 with a view to it not only replacing your older amp but also your digital source. As well as operating as a standalone device, they have designed it to be able to act as a power amp for your AV amp when operating in multichannel. The result is certainly ambitious but can it deliver the sonic goods across such a wide variety of disciplines?
Where the A-70 differs from its predecessor and indeed less expensive members of the range is that this power comes courtesy of a Class D amplifier rather than the more traditional Class A/B. This is a confident decision to make as the perception of Class D is still that it undoubtedly has a huge amount of available muscle but that many implementations have been poor (and the fact it is continuously referred to as a ‘digital’ amp probably isn’t helping either). Pioneer has some experience in making Class D work well however and like many of their products over the last decade, the A-70 has also benefitted from a visit to Air Studios for tuning which has historically yielded good results.
Where the Pioneer is a digital amplifier is regarding the inputs. As well as a choice of five analogue line inputs, the Pioneer is fitted with a digital input board comprising a single digital coaxial input and a USB connection. Both of these fittings are notionally capable of receiving a 32bit/192kHz signal although as I possess nothing recorded in this sampling rate, I have to take Pioneer’s word for that. Both of these inputs are decoded via an ESS Sabre DAC which has become a very popular chipset of late and has been used to good effect by Audiolab and Oppo in some of their digital products. Effectively, the Pioneer comes with a capable DAC built into the rear panel which has a fairly positive effect on the perception of the price. The perfect finishing touch would have been an optical connection to partner the coaxial one - even if it was shared with the coaxial to keep the inputs down. A number of devices are optical only and at these are not going to be effective with the Pioneer. The USB is like the majority of other USB connections of this nature and comes with an additional driver that is available from the Pioneer website. This installed without incident on an XP and Windows 7 machine.
Sat alongside this technological tour de force is an interesting fitment. The A-70 has an internal phono stage which even in 2013 is not that unusual - I often wonder if there is some sort of curious agreement between the Japanese brands that the first company that stops fitting them has to do some sort of strange forfeit. Where the Pioneer is decidedly more unusual is that as well as the expected moving magnet support, the A-70 will also support much lower output moving coil designs which is far less common and something of an engineering challenge to get right. A good moving coil stage is not something that is easy to find under £200 so the value calculation of the Pioneer improves another notch here too - if the stage is any good of course.
The last input is a direct one that bypasses the volume control and turns the A-70 into a straight power amplifier. This means that for all of your stereo sources, the Pioneer operates as an completely ordinary amp but seamlessly joins a larger AV system at the touch of a button. It’s a nice idea and avoids having two volume controls in the system but I don’t know how many people are actually going to use it as a facility. The only other mild concern is that the input looks the same as any of the others on the rear panel and is mounted in close proximity to the ‘normal’ inputs which could be potentially damaging if you get it wrong.
The build of the A-70 feels worth the asking price. The all-metal chassis is very well bolted together and feels impressively substantial. The review sample was black and while it looked very smart I did find that under electric lighting, the volume position was not something I could immediately tell at a glance and the position is indicated only by a notch which tends to become invisible. Otherwise the controls are logical enough and sensibly laid out. The matching remote is a nice piece of industrial design but as it is a ‘system driving’ design, it has a great many buttons, some of which do nothing in the context of the A-70 on its own.
First up, you can put aside any thoughts of the Pioneer sounding harsh or in any way synthetic. Across all the speakers it was connected to, the basic trait of the Pioneer is a rich, full and ever so slightly warm performance that walks a very neat line between flattering a wide variety of music and keeping the detail and ‘bite’ required to make music sound exciting and give a sense of realism. This setup could have been achieved with any amplifier class on the market (and probably a valve amp too) but of course the Pioneer manages it while being commendably energy efficient into the bargain.
There is plenty of headroom on offer too. None of the speakers I tested it with, including the somewhat insensitive Neats, required the Pioneer to be driven to anything beyond the 11 O’clock point on the volume dial and in the case of the rather more sensitive Audio Note’s, a great deal less than that. The noisefloor is so low as to be nonexistent even with the amplifier sat at high level with no signal passing through. If you are a classical music fan, this is an amplifier that is going to let recordings do what they need to do without ever getting in the way.
The overall tonality is good too. The slight warmth to the A-70’s presentation means that voices are generally very well handled and commendably lifelike. Instruments are also impressively rich and vivid without sounding overblown and forced. The Pioneer manages to produce an effective soundstage that manages to rise and fall in size with the music being played. Placing the Naim ND5 XS on full shuffle and letting it potter its way through a few thousand tracks, suggested that the Pioneer is a very even handed performer and make an equally good fist with Underworld live as it does with the stripped back jazz of Nils Wulker.
I think one of the reasons that the Pioneer has the tonal balance that it does is down to the digital inputs. Switching the Naim over from an analogue connection to a digital one moves the presentation to a slightly more upfront and aggressive one. The digital inputs are very good - they manage to avoid sounding thin or synthetic at any stage and the USB driver in particular works extremely well - but some of the sweetness of the presentation using the Naim over analogue is lost.
Thanks to being a little more forward, the digital inputs do show up another slightly detrimental side of the A-70’s performance. As I mentioned earlier, the figures that Pioneer quote are into four ohms and although the A-70 has plenty of real world volume, the bass performance is not quite so convincing. Switching to either of the two class A/B amplifiers available, a Cambridge Audio 851A and Naim SUPERNAIT, tends to generate a little more low end shove and actual bass depth than the Pioneer can muster. Both of these amplifiers are more expensive than the Pioneer but I suspect that a ’90 watt’ class A/B amp (rated into the more convention 8 ohm measurement) that cost the same as the Pioneer would probably show up this slight lack of clout as well. The bass the Pioneer does generate is detailed, and commendably fast but it even via the isobaric arrangement of the Neat, it isn’t a rattle your fillings sort of amp.
It does have one very surprising party piece left in the inventory that I wasn’t really expecting when I sat down to listen to the A-70. Having done the bulk of my critical listening via digital sources, I decided to try the internal phono stage mainly to see if it had the same basic performance characteristics as the rest of the amplifier. The short answer is that it does but that rather sells short just how good it is. Using a Rega RP6 with an Exact moving magnet cartridge first of all, the Pioneer kept the same impressively low noise floor as the rest of the amp but it is the sonic performance that really surprises. All of the positive traits of the A-70 combine to produce a sound that is detailed, agile and - perhaps most intangibly - fun. Listening to Kraftwerk’s awesome Minimum Maximum boxset, the Pioneer pounds along with a massive soundstage that is instantly believable. The moving coil option is a little lacking in gain compared to the moving magnet setup (introducing the amount of signal boost required without lots of noise is not easy) but the Pioneer does a much better job that it has any right to. If you are a vinyl user looking for a new amp, this is a bit of a surprise hit.
- Detailed and controlled sound
- Impressive feature set
- Good build quality
- Slightly lacking in low end punch
- Could do with an optical input
- No shortage of competition
Pioneer A-70 Integrated Stereo Amplifier Review
You don’t need to spend much time with the A-70 to know that Pioneer is taking two channel seriously again. This is an amplifier that has clearly been the result of a great deal of thought into what a stereo amp in 2013 ought to be able to do. The result is a very flexible and capable amplifier that can be used in a variety of ways with a wide range of source equipment and deliver an excellent sonic performance while it does so. There is no shortage of competition from both the rival Japanese brands and from Europe but there isn’t very much anywhere near the price that can be a direct source for your computer audio, enthral with a turntable and then be switched into an AV system at the flick of a switch.
All this flexibility has been bought at the expenses of a few small sacrifices. The absolute power output is not as high as the bald numbers might suggest. An optical input would have been a useful addition to the list of inputs already on the amp and controls that are easier to follow when not directly illuminated would be very welcome. Overall though, Pioneer has built a very interesting and usually very enjoyable amplifier that should prove an effective partner for a great many systems.
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