The 'SH-301 Pro', Shonyun's top class-A headphone amplifier model is now available on eBay for around £310. Weighing 1.5Kg, with bulky heat-sinks and a dual box design it certainly looks serious. On the inside it uses 2 NOS opa627 opamps and high quality resistors / capacitors by KOA, DALE and ELAN. The buffer stage uses 'ON semiconductor' MJE15030 and MJE15031 (50W/8A) to provide a powerful output. The Hengnui transformer utilises the LM338T high current ,voltage regulator in a dedicated PSU to provide a 28V output, keeping the power and sound as clean as possible. Measuring 110x100x48mm, the power supply is very close but 10mm less in width and 3mm lower, they would sit together fairly well, with only a slight overhang on the amplifiers heat-sinks.
This model is designated as 'Pro' on the website (although not on the chassis). The original SH-301 model had solid wooden panels on the sides. The higher current going to this new model requires some heavy duty cooling. This seems to work well as heat still doesn't build up until an hour or two of use. So, down to the important stuff - Is the Shonyun flagship a lot of hot air or does it produce some smoking sound quality? Let's find out.
SOUND
As soon as I heard the sound from the Shonyun SH-301 I was blown away by a wonderful sense of air and authority. This sound is super clean and has a lovely brightness without suffering any harshness from an overly forward midrange or treble. On the contrary it feels beautifully balanced, well crafted and controlled. There is a deep and vast sense of space and authority that impressed me from the very start and went on impressing me track after track. I expected to get used to any benefits it had to offer after a while but it just hasn't happened yet.
Bass is both deep and nicely textured. It doesn't suffer from being overly bloated or recessed, it exudes a powerful a feeling, kicks hard and renders beautiful details to instruments. Vocals sound superb here, driven by a wonderfully clean, smooth and textured mid-range. Probably the most impressive feature on display here is the treble, again there is an amazing balancing act between a lively detail and an articulacy that avoids sibilance, it brings a rendition and separation that is a blissful experience.
PORTABLE AMPLIFICATION
Using the SH-301 to amplify the line-out of an iPhone 4 produced a lovely sound that displays the phone's tenancy for brightness and controlled it well. It offers a nice upgrade to the experience of the devices internal amplifier, but I can't recommend it purely for this use. Moving to the headphone output of Google Nexus 7 I expected less because of dual amplifying the signal but was surprised to hear an even more exciting mix of sound. The warmer presentation suited the SH-301 even better than the iPhone 4. The experience was similarly true with the Samsung Galaxy S phone, which I also had to dual amplify due to a lack of support for line-out. Which presentation you prefer will be one more of personal preference than anything else, the SH-301 copes with them all very well.
DAC AMPLIFICATION
The SH-301 feels like it could amplify almost anything with great care and finesse. Portables work well, even when they are already amplified, but the real pay-off here comes from higher quality sources. Driven from the Epiphany Acoustics E-DAC* the experience was taken to a whole new level. Everything here is like it's on steroids. I prefer this sound over Epiphany's own EHP-O2 amplifier, although at nearly twice the price of Epiphany's DAC and amp combined you would probably expect this. Moving over to the DAC of the Yulong D100 mkII and things get even better. This combination has been one of addiction for me since I got the SH-301 Pro. The smoothness, power and soundstage that it produced really blew me away, even compared to the Yulong's internal headphone amplifier. Again this is saying something because D100 mkII's internal amplifier is really very capable.
* All DACs were connected to a PC via USB, running lossless files through JRiver's media player (MC17) and using the bit-perfect event style WASAPI output or high quality streaming through Spotify Premium.
DESIGN / BUILD
The design is pretty solid. Its striking and functional with a bit of flare. There are a couple of odd design choices though, the first of which being red, green and blue lights, which feel a little tacky. The volume dial will be a personal thing but it didn't inspire me and certainly not when interacted with. The action is not tight or fluid but the worst aspect is the stepping. The first few notches display no volume at all. With sensitive headphones like the Denon AH-D7000 you get to decent volume after only two more steps and the first one displays a rather unnerving amount of channel imbalance. I got around this mostly by reducing the volume of music going into the amplifier, this is not really ideal but it seemed to work OK with the computer. It would have been nice to see a finer granularity to the volume steps and/or a gain switch here. Less sensitive headphones had no issues with the volume stepping at all however. Listening to the 600ohm Beyerdynamic DT880 easily powered these headphones to very loud levels, with lots of volume to spare, and whilst maintaining it's transparent and authoritative sound quality.
The front connections give you one of the inputs and the only output for headphones, both of which are the smaller 3.5mm (1/8") type. I don't mind this so much for the alternative input because it's backed up by RCA inputs on the back, but to not have the larger 6.35mm (1/4") headphone connection option is a bitter disappointment considering the price and market. The RCA fittings were rather loose, so much so in fact that most cables would literally fall out. It sounds scary, but I didn't notice any adverse effects due to this.
The input cable for the power supply is on the front of the unit and output at the back. If only these could have been kept on one side the amplifier could be stacked neatly on top but as it is you will most likely want to hide the power supply away somewhere. It seems like a bit of an oversight considering Shonyun have gone to the trouble of designing the power supply to match the amplifier. Both the power supply and the amplifier unit have their own power switch, which is a shame. It feels like a single power switch would have been a much nicer interaction.
The SH-301’s physicality and design feel a bit rough around the edges. The volume dial, connections, lights and general build quality all feel a bit lacking considering at its price tag, but fortunately the sound is anything but lacking. The Sh-301 more than makes up my cosmetic concerns with some serious sound quality.
If you are looking for a neutral and revealing amplification from a high quality source where sound quality matters more than aesthetics then I can’t recommend the SH-301 enough.
