Graham Slee Solo Ultra Linear Review
Thanks to Graham Slee for the loan.
First Impressions: So out of the box it came and it’s a light little thing, or maybe it’s just light beside the power supply? I have the upgraded PSU1 power supply and it’s a really heavy solid block. God whatever’s in it, I feel like you could build houses with the thing. So the amp, it looks kinda nice. Now I haven’t pre planned how I’m going to actually hook the thing up, I’m realising I probably should but too late now. Right, ghetto solution it is. Hp out of the E9 and to the AV inputs on the back of the amp. A classy looking solution this is not but hey it’ll do till I can face spaghetti junction.
It seems sensible to pull out the HD600’s has they are quite easily the best big cans I have. First thoughts on listening, please bare in mind I haven’t used the 600 in a while so I do forget just how excellent they are sometimes. I don’t know if it’s maybe just the tracks but things feel deeper and more holographic. Highs seems super refined, highly easy on the ear yet just so choc full of detail. It’s all completely uncritical non comparative listening so I know it means little but…… everything feels unquantifiably better. Not brighter nor deeper lows nor more forward mids but I keep coming back to wanting to describe them as holographic. These just feels something better and as I haven’t been able to quite swap back to just the E9 and actually do some proper critical listening I just cannot for the life of me put my finger on it. Something effortless feeling somewhere.
Lows: While I get the impression that the HD600’s are being better driven in the lows which when you get deep can cause issues for amps, there is something effortless. As the only proper desktop amp I have, the E9 which I still think is super bargain levels of value, the Solo, well the Solo doesn’t even notice it. In the way that a great battleship might sail unfettered right though a harbour of toy boats. Playing with the Oppo PM-3’s and flicking back and forth it’s blisteringly apparent that the bass feels so much weaker on the E9, it just lacks the vigour and authoritative reach that the Solo gives it. It’s not per say larger in the bass it just feels better are more articulated. The E9 is struggling. Honestly it’s most annoying for until the Solo I was very happy with the power the E9 was capable of delivering and new I’m thinking I’m forever going to be aware of what it lacks now.
Quantitatively, the Solo actually feels perhaps a tiny fraction less bassy than the E9. Less so that the bass is diminished but that it’s more cleanly delivered and therefore there is that hint less in the way of bass bloom. The Solo isn’t particularly forgiving when it comes to low end articulation so you may want to try and feed it better quality stuff than some of the bass as is found on Miss Gaga’s tracks.
Mids: It’s the same story as was with the bass. The Solo feels like it is casually spiting it out at you and that its capable of doing vastly more should you ask it to. The E9 feels like it’s already giving you it’s all. They are just not in the same class. It also becomes more notable that the separation between what a grown up amp, hooked up to the mains can do that a portable one running off a battery cant. Flowing, and effortlessly detailed. It’s just all so openly expressive, Regina Spektors “Ballad Of A Politician” with its eclectic cacophony of sounds feels so wonderfully layered an ensemble. Everything is so singularity clear and distinctive you can mentally tear it from its place in the song and examine it to your heart’s content. The imaging vocally is kick ass good. The only real issue is if you feed it crap, you see info that you might happily wish it would more melt into the whole.
Tonally and quantitatively it’s a little bit middy and a little bit open. The smoothest high quality vocals are too expressively rendered to truly give you that creamy, melty, Galaxy advert type sumptuousness. There isn’t the thickness that works so well with creamy vocals.
Highs: Much refinement, much detail, much nuance. To be honest you wouldn’t have expected otherwise would you? The difference is the more noticeable in big cans but it’s still noticeable with IEM’s too. Things that are very easy to drive still manage to benefit from, well from what exactly I don’t know. Maybe it’s the extra headroom in available power? Maybe it’s a slight inclination towards an open and detailed sound signature? It’s not what I would ever call “bright” you know, things like the Icon mobile or the FireyeDA they are bright, they have that noticeable lift and dazzle in the upper end. The Solo doesn’t really do that, it’s just a little more explicit all over. Actually when you really, really start to look closely at the treble it’s pretty mild. The initial metallic impact of a cymbal is ever so fractionally dampened. The immediate rattle and decay are both effortlessly perfect. Just exactly how I would want them to be but I know that being ever treble sensitive, there will be those that love the raw brutality of impact.
It’s curious in that its edge it a hint calmed yet its exceedingly high level of clarity otherwise makes the treble more noticeably distinct and clear. So when you get elevated levels of clarity giving the impression of brightness you aren’t really, you are just getting more explicitly distinct treble.
Connectivity: It’s a pretty clean and simple affair. You get two pairs of phono connectors on the back, input 1 and input 2. While in normal usage I dunno what I’d do with the second input but for reviewing? Oh god trust me, it made my life soooooooooooo much easier.
Interface: Super simple. 6.25mm headphone socket on the front. Volume dial. Then lastly we have the input switch, it can be for input 1, input 2 or in the middle which makes no sound come out. Effectively it acts as a mute button.
Power: Gobs of it. Not only did it continuously feel like it was never in the slightest straining or that it didn’t have endless reserves, it could go loud. I never got the dial past 12 o’clock and that was with the HD600’s and with a fairly quiet recording. It always felt like there was tons and tons of headroom left it you need or wanted it.
Dynamics: Dynamics tends to be more headphone dependant but with the power availability it never did that, hint of volume decline when a song explodes out from silence. There was plenty of dynamic range to call upon at any instant. It was perfectly happy to trundle along, meek and mild then rip your ears off. Great for music but it did occur to me how much I don’t love that in movies. Not that you buy the Solo for film watching but its dynamics I think could irk me after a while.
Transparency: Exceedingly transparent. Very open and detailed. It does it too without being particularly breathy so you do retain much liquidity. I suspect that’s where its “valvey” purported nature comes from. Still, oodles and oodles of detail and transparency.
Build: It’s a block of aluminium. It has a hint of DIY esq charm as you can see clearly how the external casing is put together. A bit of handmade craft like appeal about the thing. It feels solid, sturdy and that if you dropped it it’ll chip your floor rather than explode on impact.
Value: Hmm. I’m not an idiot so I fully realise that we are in the realm of diminishing returns. I realise that if I had the Solo SRGII here which is the near twin of the Solo Ultra Linear Diamond Edition that I have here, it’s circa £400 for the standard verses the £670 for this version. Even comparing to the FiiO E7/E9 combo it would be silly to say that any high end audio equipment is “good value” but more do you get something of worth for your money. The answer there is a clear yes. The Solo Ultra Linear came in and quite effortlessly battered the snot out of every amp I have. Sure it’s the most expensive so it should too. It just opened up a new layer of performance from pretty much every single thing I plugged into it. Even the itty bitty Trinity Hyperions I’ve been playing with lately. I’m not saying that if I had £700 to play with I’d put £30 to the Hyperions and £670 to the Solo Ultra but if you’ve already got some first rate stuff, yes you will see an improvement over any mainstream output. It’s not about getting great “value” it’s about eking all that you can, making your headphones be the best that they can be.
Conclusion: Within a couple of days of getting the Solo Ultra in I came to a stark realisation. That one it was very good but secondly that part of me wishes I’d never heard it. You see as a rule I’m an IEM guy, that’s what I use most and they don’t really need oodles of power. They also are for use on the go, not so much as being wedded to a desk. Therefore I was happy with how everything performed and I had my E7/E9 combo for throwing a bit more power in when I wanted to. In my head I knew it wasn’t the greatest desktop amp in the world but I was happy with it. Now I’m not.
Spending hour after hour messing about with cables and headphones and IEM’s and amps and the variety of combinations you can make, the Solo Ultra just lifts everything it was hooked up to. Sure it couldn’t make a £30 IEM challenge a £200 one being played out of a meh source. It’s not a magic wand. It did however immediately offer a new layer, not only in quality and detail but it improved the acoustic layering. I feel almost a little spoiled in what it can do to things and then to go back to my old set up feels as though something has been stolen. That hint of life, of vibrancy, of dynamics, of nuance has just ever so slightly been taken away. Everything feels diminished and it makes me sad.
The Solo Ultra Linear therefore stands quite easily head and shoulders above everything as the best amp I’ve ever encountered. It’s that simple. It is wonderful. The however is that it’s of course not the cheapest amp I’ve ever encountered. To most people out there it would simply be wild overkill to spend so much on an amp. The fact is you pretty much always get a far bigger improvement in audio quality by putting it into a more expensive headphone than into an amp. So if you don’t have a great pair or two of headphones then I’d strongly suggest you get them first. Then when you want to make the your favourite headphone the very best it can be, maybe then have a think about the Solo Ultra, maybe give their home trial / loaner programme a bash and see if you like it as much as I have.