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Integrated amplifier


SA 710

Manufacturer: SOULNOTE, inc.
Price (in Europe): 1799 euro

Contact: tel.: +81 44-322-0064



Product provided courtesy of: Nippon HiFi

'm pretty sure that I've mentioned that already more then once but I'm going to do that again. Sometimes a pure coincident decides about what gets reviewed. In this particular case coincident happened thanks to one of the popular social networking services (the one who's name starts with “F” and which is supposed to be passé already). I'm not really a person who is particularly active in the Internet but in this particular case being a member of many audiophile groups gives me access to a continuous stream of (often useless) information and news from audiophile world that I wouldn't otherwise have time to look for in many different places. Few months ago one of such information caught my eye because of two things. First of all it referred to supposingly very interesting Japanese audio manufacturer I'd never heard of before. Secondly this Japanese company had a representative for international trade in Hong Kong. That got me wondering – a Japanese company with Chinese representative? So was it a Japanese company manufacturing their products in China? That was enough for me to do some research about the brand and to start a discussion with a guy, European distributor, who delivered this particular news that caught my eye.

This man – Jani Leppälammi – turned out to be a nice and helpful guy who eagerly gave me every explanation I required. You might have figured that already judging by his name – Jani is from Finland and his company called Nippon HiFi is a SoulNote's European sole distributor. As he explained most SoulNote's products are made in Japan )accept for an entry level line), and a representative in Hong Kong is just a sign our times. After a little talk Jani offered to deliver some product for a review and I, intrigued by the whole story, accepted. I have to admit that I didn't really study SoulNote's portfolio that much as I didn't know which product would be available for review. So I just waited patiently for whatever was coming.

Finally, one day I received information that an integrated amplifier, SA 710, was heading my way. Information came when I was really busy so I did not even check any information about this particular model. When a courier brought me surprisingly small and light parcel I started to wonder what exactly I got myself into? Some D class amp review? Amp was really small and 6 kg didn't impress me either. I couldn't help but wonder how such a „baby amp” could sound like?! It was already there so I unpacked it. The first impression was pretty good – make and finish seemed to be of more than decent quality. Not a potential beauty pageant winner but considering it's price (I already knew it) a truly nice contender. Maybe the back panel wasn't that impressive as I'd already got used to while reviewing other products similarly priced (vide recently reviewed Teddy Pardo's set) as they'd sported high quality WBT RCA sockets. The ones used for SoulNote surely weren't of that class but looked solid enough to do the job. A thing that might be improved – spaces between RCA inputs could be bigger – now they are quite close to each other which means using larger RCA jacks might be a problem (at least if you use all 3 inputs). Anyway in my opinion advantages outweighed these small flaws – there are 3 RCA inputs, a XLR one, 2 pre-outs, headphone (large jack) output, very nice speakers bindings, an a switchable gain (for speaker outputs) – nothing to complain considering the price of the device, maybe even more than expected. OK, a remote would be a nice addition, but I can live without it and without complaining about it.

After having a first close look I did something I usually avoided to do – I plugged SA710 to my system (with Alter Ardento 1 speakers) and started to listen to it before I checked out a manual. Music started to flow and my jaw started dropping towards the floor... - what the heck?! - I thought to myself – is that really an amp for 1800 EUR (well, today when Nippon HiFi is switching from direct sales to building an European distribution network it's actually 2200 EUR – still more than fair)? What a nice slam! Music kept going and I finally found a manual in an email from Jani (maybe if I'd got a hard copy with amp I would have read it before listening session) and... another surprise. Manual clearly states: „use with speakers with at least 8Ω loading. Using SA710 with lower loading might result in audible distortions to the sound”. For those who don't remember, or simply don't know – Alter 1 speakers have a nominal impedance of 4Ω. So where the heck are these distortions?!! - I thought again. SoulNote simply rocked with Alters and it obviously didn't care at all about their „too low” impedance. OK, so lets check what's the power output? I guess at least 40-50W? I found a specification and it read... 2 x 10 W. WTH?! (to be clear, I meant „What The Hell?” ;-)). One of the rules one should follow in audio world says: follow suggestions of your system/devices manufacturer, he usually knows better, unless of course reality proves otherwise. And this was a classic case – this tiny Japanese buddy drove huge Ardento speakers with an ease and I truly liked what I heard so I kept them is the system. One more thing that I found in the manual – it said that manufacturer offered some sort or feet for this amp that should really make a difference in the sound. These were not included in the package I received – as Jani explained they got lost somewhere as the amp visited already some reviewers and potential customers. He offered to send me a set but I decided that I would go with my trusted Franc Accessories Ceramic Slim Discs – these never failed me before and I found out soon enough that they would work perfectly also this time.

Let me get back for a second to the matter I haven't really covered so far. I don't know about you but for me a SoulNote brand is something new, I don't think I've ever heard about it before. I can't even tell you the Japanese address of the company as it is given on their webpage only using Japanese alphabet. But if you want to have a look at the company I suggest you go to this link HERE, for a short factory tour. It gives an impression that SoulNote is quite a big company. Jani sent me a history of the company that shed some light on where they came from. It seems that SoulNote brand hasn't been that long on the market, just since 2008 when the first integrated amplifier with SoulNote logo hit the market. The “father” of the brand is Mr Nakazawa, today a president of the CSR group, owner of SoulNote brand. That's the man who brought a lot of experience and knowledge to this company as he's been in audio business for much, much longer. He designed audio devices already in analogue times – tape recorders for example. Later he was a part of the team that designed some world's first devices like, for example, a two box CD Player with separate transport and DAC – the Philips LHH1000, first bitstream CD Player (LHH500), first non-NFB player (LHH800R). Long story short - Mr Nakazawa participated in many pioneering projects in audio industry. If nothing else that is a very strong argument to give devices that were designed by him, or his engineering team, a credit of trust.
When reading materials sent by Jani two more things attracted my attention. First of them was information claiming that all SoulNote's designers were also musicians – who knows better how a live music sound like if not them? The other thing was company's slogan that read: „Sound resonating to the Soul”. That spoke to me strongly as I was just a guy who loves music, not the equipment that reproduced it, so I always expected most of all to be touched by what I could hear from reviewed products. I accepted this slogan as a promise from SoulNote. There was only one thing left to do – check out if SoulNote kept up their promise.

Recordings used during test (a selection):

  • AC/DC, Back in Black, SONY B000089RV6, CD/FLAC.
  • Aerosmith, Pump, Geffen Records, FLAC.
  • Al di Meola, John McLaughlin, Paco de Lucia, Friday night in San Francisco, Philips 800 047-2, CD/FLAC.
  • Arne Domnerus, Jazz at the Pawnshop, FIM XRCD 012-013, XRCD/FLAC.
  • Cassandra Wilson, New Moon Daughter, Blue Note CDP 7243 8 37183 2 0, CD/FLAC.
  • Dyjak, Publicznie, UBFC Cd0111, CD.
  • Eva Cassidy, Eva by Heart, Blix Street 410047, CD/FLAC.
  • Frank Sinatra, Live in Paris, MFSL 2-312, LP.
  • Georges Bizet, Carmen, RCA Red Seal 74321 39495 2, CD/FLAC.
  • Guns N' Roses, Use Your Illusion 2, Geffen Records B000000OSG, CD/FLAC.
  • Isao Suzuki, Blow up, Three Blind Mice B000682FAE, CD/FLAC.
  • Kermit Ruffins, Livin' a Treme life, Basin Street B001T46TVU, CD/FLAC.
  • Lee Ritenour, Rhythm Sessions, Concord Records CRE 33709-02, CD/FLAC.
  • Mozart, Le Nozze di Figaro, Harmonia Mundi HMC 901818.20, CD/FLAC.
  • Patricia Barber, Companion, Blue Note/Premonition 7243 5 22963 2 3, CD/FLAC.
  • Renaud Garcia-Fons, Oriental Bass, Enja B000005CD8, CD/FLAC.
  • The Ray Brown Trio, Summer Wind, Concord Jazz CCD-4426, CD/FLAC.

To be honest I don't really remember what exactly was this first album I played that impressed me so much – it was something with leading bass guitar so most likely one of Marcus Miller's recordings. So after realizing what kind of amplifier I was dealing with, knowing I hooked up “wrong” speakers but being still under huge impression of this first record, I decided to play AC/DC's Back in Black (from a FLAC file).

A small digression – just a few days before SoulNote arrived I'd received two small devices that I was personally interested in to check out if and how would they upgrade my PC used as a main digital source for my system. One of them was a JPLAY USB card, and the other was a battery power supply for it – a Bakoon BPS-02 (that was recommended to me by Marcin Ostapowicz himself, as he used two of these in his own system – one for card, one for a system SSD). I was waiting for both of them for a while impatiently, as in my opinion USB cables didn't make that much of a difference, but a USB card with this PS was supposed to really positively affect the sound. When both devices arrived I faced a little problem – there was no proper cable to connect them. I realized quickly that buying proper cable was simply impossible – nobody offered what I needed so I was faced with two options – I could do one myself (and I knew very well it was a bad idea) or to find a professional who could do it for me. Some of you might heard of company called Tomanek. They manufacture a lot of different power supplies (for musical instruments but also for D/A converters), power cables, power distributors and so on. It took me exchanging two emails with them and the very next day a courier knocked on my door bringing a small parcel with two very nicely made and looking cables that cost me less than shipment. That's the kind of customer service I'm talking about!
Anyway – a day before SoulNote arrived I finally installed JPlay card with Bakoon PS in my AudioPC using Tomanek's cable and... I guess many of you experienced something like that before. You know and love your system very much, and than one day you try some small upgrade (I'm not talking about anything major like speakers or amp), and already during first piece of played music you get all bananas? You thought your system sounded so good, and it got so much better after this small upgrade. Yup, I thought my dedicated Audio PC was already a very good source of digital system for my amazingly good Bada Alpha converter. But improvement in performance was clear as a day – comparable to changing a source for something from a higher class. No USB cable I had a chance to check in my system has ever introduced such a clearly positive improvement of performance. And some of them could easily pay for JPLAY and Bakoon together. Why mentioning it here? First of all it was an interesting experience for me I wanted to share with you – before you spent some hilarious money on USB cables check first if you can improve the signal from your computer – there is more to gain there. Secondly I wanted you to realize that when I started to listen to SoulNote I was already in “bananas phase” so it wasn't easy to impress me even more. But this small Japanese amp managed to achieve that and that said a lot!.

Back to AC/DC – I decided that if SoulNote could play that kind of music it would play anything. Obviously it was not some sophisticated music, but to sound well it required proper rhythm, power, dynamics – elements that many wouldn't expect from a 10W amplifier, right? But as it turned out all SA710 needed were easy to drive (even if not recommended 4Ω loading) speakers to rock the party. Seriously! Well, at least in a mid-size room, but when I opened windows many neighbors enjoyed the party too. I had a few much more powerful amps here that were not able to do the same, meaning to offer that much power to the music of Australian veterans. The 15-inch woofers delivered nicely extended, punchy and well defined bass. It was supported with a detailed, transparent midrange (in this case – mostly vocal), and a very clean, airy treble. It seemed that 10W was more than enough to control all that energy and to delivered it in an orderly, uncolored way. In fact I liked SoulNote's performance in that kind of music so much that instead of moving on to more “suitable” music genres I continued with more AC/DC, Aerosmith, and good, old Guns'n'Roses (not the latest crap if you know what I mean). In each and every case it was a real fun to listen to. I was pumping up volume (of a kindness of my heart obviously, to share this joy with others), feeling the rhythm and simply having a great time.

After all that rock craziness delivered mostly from non-audiophile quality recordings (although I had to admit that 24/44,1 Pump from HDTracks sounded significantly better than others) I moved to Lee Ritenour's Rhythm Sessions.

That is one very nicely produced material, with some great guitar (bass and electric) recordings. SA 710 was able to benefit from tracks' better quality providing more sophisticated, more detailed performance. It was able to differentiate bass very well – something one might really not expect from 10W amp. Bass was also nicely defined and controlled, and more taut now, when the input signal was of better quality. The AC/DC music sounded powerful because it was delivered as a “wall” of sound, this time each pluck of bass guitar string had a fast powerful kick and energy that was later sustained if necessary.
It looks like I focused on the low end but I did so because considering the fact that I was reviewing a low power amplifier impressive bass performance was most surprising. I'd heard many much more powerful amp that couldn't drive the same speakers with such an ease, in such a convincing way. Yes, some of them were able to dig even deeper and make bass sound even more taut but the fact was that for most music it did not really matter, and secondly most of these amps cost much more then the reviewed SoulNote.

After my blues-rock sessions I decided to keep pushing SA 710 and instead of going to its (most likely) preferable acoustic and vocal music, I played some (also acoustic but of much, much larger scale) orchestral music. I started with two favorite operas – Mozart's The marriage of Figaro (conducted by Jacobs), and (of course!) Bizet's Carmen with wonderful Leontyna Price and von Karajan conducting. And again SA 710 surprised me with the most enjoyable performance. There was a nice depth to the soundstage with good layering, whatever happened in the front of the stage was detailed and three-dimensional, events in the back of the stage not that much but hey, that's an inexpensive, low-power amp! Vocals seemed palpable, with nice timbre and texture rendering and the emotional layer, the drama of the performance was conveyed in a convincing way similar to that of SET amplifiers. The presentation was involving, pulling me into the play's intrigue in both cases – the Mozart's, more comedy like, but also in Bizet's, definitely more dramatic one. SoulNote proved to be capable in terms of resolution and selectivity. Although the more expensive amps, including my own Modwright, were able to deliver even better performance in these areas, the Japanese contender had nothing to be ashamed of. It couldn't maybe compete in terms of presentation's holography with my SET amp, but still it was hard to believe that I listened to inexpensive solid-state amplifier. Three-dimensionality, palpability of the singers suggested that it had to be delivered by a tube amp and a good one I must add. Plus this dramatic, emotional side of, well, theatrical performance also reminded me a lot of what good tube amps usually delivered. A conclusion was simple – the Japanese designers of SA 710 (let me remind you – musicians themselves) like many other Japanese audio engineers had taken care of proper midrange presentation as they'd known it had been the most critical part of frequency range. It's not enough to make it detailed and transparent for midrange to sound natural. In my opinion (and it seems that guys from SoulNote would agree) there has to be some warmth to it. I know I wrote that already many times in many reviews but let me repeat it again – when you listen to a live performance with vocals and acoustic instruments they always have some warmth to them, they never sound cold, nor even “neutral”, they simply must lean towards warm side of things. So if you create a device that tries hard to deliver very neutral sounding performance at least these element – human voices and acoustic instrument will not sound really natural. Electric and electronic instruments might be delivered in a “cold” fashion and still sound good, but the “natural”, not electrically/electronically enhanced sounds need some warmth, period! The Japanese realize that very well and no matter if they create tube or solid-state devices almost all of them deliver properly warm midrange. That's why so many people, me included, love listening to vocals and acoustic music via Japanese audio systems.

That's why I sat like enchanted in my chair while listening to Carmen and to the wonderful, dark, but smooth, powerful and rich voice of Leontyna Price, experiencing a drama happening in front of me. Bit later when analyzing what I heard with a cool head I could tell that for example the size of the soundstage, especially its depth, wasn't so well conveyed – the marching choirs, that I so often mentioned in my reviews, seemed to march closer to the front of the stage than usually. Also, comparing to reference system, all the events in the back of the stage weren't so detailed, so precisely rendered. That didn't affect the general perception of the performance so much, but if you're into analyzing and comparing every detail of the presentation you'd probably noticed that. But again – considering the price of this amplifier you can't really complain – if it did everything perfectly they would ask much higher price for it. While listening to symphonic music I was equally surprised as when playing rock, with an ease and power it was delivered with. Assuming you had proper speakers for this amp you'd be rewarded with a detailed, resolving sound, much better then you'd expect from a device at this price point. I didn't really feel any power limitation of SA 710, no clipping, distortion or whatsoever, although I did not try to achieve anything close to a realistic “symphonic” volume level (not recommended ever in your room!). SoulNote using 15 inch woofers moved a lot of air creating impressive sound pressure and that brought me closer to a live-like experience then I could have expected. The little SoulNote really put some effort into rendering proper timbre of instruments – I loved the way it presented wind instruments, and the string ones performed equally convincing. Any attempt of delivering live-like performance of an orchestra in a regular room is doomed to fail – no way to deliver proper scale, dynamics or power, but SA710 delivered such a coherent, musical, and surprisingly unforced performance that I enjoyed it a lot (some credit for that should go to Ardento Alter 1 too).

Last but not least it came to playing music that this setup – SA710 + Ardento speakers – seemed to be made for. I already mentioned how impressed I was with vocals when listening to operas. But when it came to “audiophile” pieces of music with leading vocals – like the ones from Patricia Barber, Eva Cassidy, Cassandra Wilson or Frank Sinatra – SoulNote's ability to convey timbre and texture of voices combined with their palpability and convincing expression created a kind of presentation one would expected from a much more expensive amplifier. The acoustic instruments also sang with a rich, detailed voices, and the SA 710 did its best to deliver their timbre properly, to make them sound vibrant, lively, with a fast attack phase and a nice decay. Soundstage, which I noticed already when listening to Carmen wasn't that spectacular element of the presentation but was surely good enough not to complain about it – simply some other amplifiers were able to deliver even bigger one, especially with some more depth. But still – every instrument on the stage was precisely placed, each was a 3D image even if not that precisely outlined, but with proper size and especially with smaller bands the presentation was quite convincing (space-wise I mean) and natural. Yup, that's a key word here – natural – if someone asked me to use just one word to describe the presentation of vocal and acoustic music that's what I'd use. So I'd say that the above mention SoulNote's slogan is not just an empty promise – SA710 does just that – touches the soul of a listener. There was so much nostalgia and melancholy in Eva Cassidy's voice, velvet smooth vocal of Frank Sinatra SoulNote dealt with it smoothly, but the rough, sometimes even aggressive voice of Dyjak was as realistically rendered as that of Sinatra, and the one and only voice of Louis Armstrong hardly ever sounded so well in my system.

A very good experience with wind instruments pushed me towards some New Orleans’s jazz. Kermit Ruffins' trumpet and Wycliffe Gordon's trombone charmed me with a delicate, smooth, almost silky voices to turn in a matter of second into grasping, vibrant and rough sounding brass instrument that they actually were. Ray Brown's double bass – colorful, powerful, with lots of wood in its sound was truly enjoyable. It was unfair to expect of a 10W amplifier that it would deliver such a gripping, nicely defined double bass performance but it did it anyway. Again there was no sign a of SoulNote's low power output – no distortion, no clipping or whatsoever but a great definition and differentiation of low end. The sound was open, with lot of air around instruments and each of them breathed and vibrated the air that carried sound towards listener. Listening to more and more recordings I realized that I kept compering what I heard to what I remembered from many SET amps performances. It might not have been the same level of performance – good SETs sounded even better than SoulNote, but the sound characteristic was similar. That was definitely an amplifier for music lovers, not for hard-core audiophiles.

Just very shortly about headphone output – it turned out to be pretty good. I used it with Beyerdynamic T90 and Final Audio Design Pandora Hope VI and in both cases I definitely liked what I heard. The T90 were, I think, the best match (out of these two) as they offered a bit bright sound (like most Beyerdynamic do) which complemented with rich, powerful sound of SoulNote very well creating involving, musical experience.


The longer the list of items reviewed gets the more clear becomes for me that such a unexpectedly well performing (relatively) inexpensive devices give me more joy that ultra-expensive ones that can't really surprise me with nothing. Not that I don't like listening to the latter, I just don't like their often crazy pricing and what one can expect by a 20000 EUR amplifier? It has to sound amazingly well – with that kind of price there us no other choice. So in fact I enjoy more finding such inexpensive products like SoulNote SA710 that are able to play music in a way that truly touched my soul. SoulNote SA710 – small, light, inexpensive solid-state amp with no NFB turned out to be an amazingly capable intermediary between music and me. It offered more than just listening to the music. It involved me in the music, let me experience it, live it. So I have to give a proper credit to the designers of this amplifier – they stood up to their promise and offered a device that reproduced music in a way that “resonated in my soul”. I'd like to recommend SA710 to all true music lovers. You have to help this amp a little by hooking up some easy to drive speakers (as my case proved not necessarily 8Ω ones). There is an additional bonus – you get also a pretty good headphone amp.

SA710 by SoulNote is a solid-state non-NFB integrated amplifier. It sports quite a small, metal, rigid casing with two color options – silver and black. Small size (especially only 24cm depth) is not the only surprise – the weight of 6 kg is another. One can't complain about fit and finish of this device, its aesthetics is also very pleasing. There are two knobs on the front panel – one is for volume control, the other for input selection. Near the left edge there is the on/off switch, near the right one there is a headphone output (for a large jack). Top cover sports a lot of ventilation holes – there is a reason for that, as this amplifier delivers a lot of heat. At the back one will find 4 analogue inputs – 3 x RCA (with sockets placed a bit too close to each other for my taste) and 1 x XLR (Neutrik sockets), and two pre-out outputs (RCA). There is also a small toggle switch that allows user to chose Low or High gain (the latter offers increase of 14 dB compared to Low one). I'm not sure what's the make of speakers bindings but I like them a lot – looked much more solid than RCA sockets, and proved to be very easy to use and reliable. There is a small plaque next to speaker bindings indicating that at least 8Ω speakers should be used with this amplifier, but my case proved that if the speakers are sensitive enough 4Ω loading shouldn't be a problem. Inside almost whole circuit is mounted on one large PCB. There are 12 TO-220 power transistors fixed in groups of three on solid, metal radiators that seem to play a role of a shielding separating pre and power sections from a power supply with a large R-Core 120 VA transformer, fast diodes, and 9 pairs of small, fast smoothing capacitors. Both driving and power sections are a fully discreet non-NFB circuits.

Technical specification (according to manufacturer):

• speakers: 2x10 W (8 Ω)
• headphone: 3 W (32 Ω)

Preout: 2 V (10 kΩ)

• speakers: 0,2% (10 Hz ~ 100 kHz, 3,3 W, 8 Ω)
• headphone: 0,03% (10 Hz ~ 100 kHz, 200 mV, 32 Ω)
• pre-out: 0,05% (10 Hz ~ 100 kHz, 2 V, 10 kΩ)

Frequency response:
• speakers output: 5 Hz ~ 350 kHz (+0/-1 dB, 1 W, 8 Ω)
• headphone output: 5 Hz ~ 400 kHz (+0/-1 dB, 200 mW, 32 Ω)
• pre-out: 5 Hz ~ 400 kHz (+0/-1 dB, 2 V, 10 kΩ)

Input sensitivity / impedance:
• H: 0,775 V/5 k Ω (inputs: 1,2,3)
0,775 V/10 kΩ (XLR)
• L: 4 V/25 kΩ (inputs: 1,2,3)
4 V/50 kΩ (XLR)

Gain: H: 22 dB, L: 8 dB

S/N Ratio: 115 dB (IHF A Network)

Power consumption: 32 W; 16 W (idle)

Dimensions: 420(S) x 98(W) x 243(G) mm

Weight: 6 kg