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Graham Slee Solo Ultra Linear Headphone Amplifier


Pros: Sounds exquisitely good. Eeks out every last drop of performance form your headphones.

Cons: Your wallet may not be best pleased.

Graham Slee Solo Ultra Linear Quick Review


Thanks to Graham Slee for the loan.


Full review here http://www.head-fi.org/t/765465/graham-slee-solo-ultra-linear-review-by-mark2410


Brief:  Teeny amp, giant name.


Price:  £670 or circa US$1020


Specification:  Lots, see here http://www.gspaudio.co.uk/soloultralinear.htm


Accessories:  Err none really, power supply if you count that.


Build Quality:  Good.  It’s a big block of aluminium which you can see the screws holding it together.  It’s sturdy and practical.


Aesthetics:  Pleasant, plain, perhaps a little utilitarian.


Sound:  Open, detailed, transparent and I could see some thinking it contradictorily either bright or valvey.  Bright because it’s so very detailed and this heightened clarity in the uppers makes the highs more articulated and readily distinct.  Rather than the smearing you get when there is a lot going on up top, the clarity retains all the detail making it more noticeable and hence could be interpreted as bright.  It’s valvey in the sense that the initial impact of metallic edges are a might soft.  The highly fluid smooth detail you get pervades everything and offers a hyper liquid presentation.  There isn’t any abrasiveness or harshness despite its very open and clear nature.  Normally you see, that “clarity” is enhanced by cranking up the abrasiveness so it “feels” more clear.  The Solo Ultra doesn’t do that, it does it the hard way by actual giving you more detail rather than just trying to trick your ears in to then thinking there is.  It’s pretty awesome.  The enhanced clarity is everywhere, from adding a certain vigour to the lows, they do reduce the tendency of headphones to bloom a little so you get a more well sculpted bottom.  It firm and luscious.  Mids share the same nudging, highly detailed, highly detailed pushing towards detail and nuance.  It does a little over do vocals which suit a more creamy presentation.  I can’t fault it for being too detailed but Nora likes a more rich and creamy experience, yes her vocals are super fluid but she isn’t about extracting every last detail she’s about melting away.  The Solo Ultra enjoys being desperately detailed and nuanced, not so much melty.  Highs are super good too.  Supremely detailed so feed it good quality stuff, while it does do a little valve esq softening of the metallic edge of a clatter but only a hint of it, feed it crap and it’ll try not to cheese grater your ears but if you buy this amp and feed it rubbish, it will assume you know what your doing and dish it up.


Value:  Eek.  It’s the best part of £700 here for a headphone amp.  So we are well into diminishing returns but….. if you’ve got some first class, kick ass headphones already and you want to see just how well they can shine, you may well want to get your wallet out and give them a bash.  It’s pretty damn fine.


Pro’s:   Sounds exquisitely good.  Eeks out every last drop of performance form your headphones.


Con’s:  Your wallet may not be best pleased.


Pros: Compact, remarkably clear sound, easy to listen for ages

Cons: several weeks of burn-in (but worth waiting for)

I had built and enjoyed the Novo amplifier kit from GSP. I wanted to upgrade to get one of the best headphone amps available.


The Solo Ultralinear is remarkably musical, it opens up the sounds within a mix and brings details out without being harsh. It does a fine job on guitars, acoustic and amplified. The detail and stereo soundstage make individual vocal tracks clear, I could hear vocal backing parts that were previously lost in the mix.


The individual drums and percussion were clearer than before on tracks I knew well, but the punch and resonance of toms surprised me. Basslines have body and clarity, with the track being clearly audible in the mix.


I was impressed with the intial sound which was pretty clear, if a slightly bright new electronics sound. It quickly mellowed with some detail and sounded full with good bass. Over the next couple of weeks the low level details emerged and the positioning of parts in the stereo mix became better and better. The burn-in is 3 or 4 weeks of being left powered up, some users say 500 hours. It is well worth waiting for the end results.


There is a light soft hiss but it is unobtrusive at normal listening levels.


The two inputs and switching arrangement is ideal for my use for phono and CD/DAC inputs.

Graham Slee Solo Ultra Linear Headphone Amplifier

The Solo Ultra-Linear uses advanced linearization techniques that mimic valve behaviour but in a solid-state implementation

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