"I started in single-ended mode throughout via the HD800 headphones with a Kimber cable upgrade. I listened to CD and Depeche Mode’s Personal Jesus from the album, Violator."
我在单端模式下使用HD800耳机，升级了线材。听了CD和流行音乐专辑Violator中的 Personal Jesus。
"The single-ended performance was interesting indeed because it offered a relatively even-toned, neutral presentation. There was no undisciplined frequency emphasis here. No badly behaved mids or bass to cause listening fatigue. The basic, core sound here was clean and well mannered. "
"The upper frequencies were surprisingly good in single-ended mode. There was much to like with good insight from the varied synth lines and vocal delivery providing good emotional insight. I was pleased to hear the emergence of quite shy elements across the wide soundstage. An acoustic guitar which appeared only of a couple occasions was noted by the SGA1."
"I turned to a balanced headphone connection, a Pentaconn variant on my HD600 S headphones, to see if that might change anything. "
"Now this was more like it! The detail from the mids remained, as did the dynamic reach around the upper frequencies in general terms. If anything, this area was extended tad. What really changed though was the improvement in tonal balance."
"The bass was suddenly back and with some vengeance too. This track needs power to drive it forward and the balanced connection certainly provided that. The added mass gave the song drive, a forward motion that swung the hips and forced the head into a classical nodding configuration. "
"The great thing about the balanced connection was that it introduced bass as a mature addition. It didn’t act like a Loudness button, swamping the soundstage with lower end frequencies in some sort of frantic torrent. "
"Hence, the detail and the open nature of the midrange remained and that information was never masked. In fact, that same information now offered a maturity and richness which made this area all the more attractive."
"I then connected the SGA1 to my reference hi-fi in balanced mode, which added more maturity and a smoothing of the midrange. The upper frequencies as a whole now glided across the soundstage in a relaxed and unhurried manner. The noise floor lowered appreciably here."
"All of which made the SGA1 sound, well sound more expensive frankly. The sound offered a luxurious playback now. More than that, the bass remained massy and powerful and still did not mask or veil detail yet was now better integrated into the mix as a whole. There was nothing flashy in the bass regions now. "
"This performance level was backed up when playing the vinyl version of ELO’s First Movement (Jumping Biz), an instrumental fronted by an acoustic (Spanish?) guitar and backed by violins and cellos plus percussion. The instrumental separation on this track allowed a heap of detail to spring forth. Each and every instrument on this track could be picked out and followed independently while each offered enough detail to the mix to delight the ear. "
在演奏 ELO 的第一乐章（Jumping Biz）的黑胶版时，这种性能水平得到了支持，这是一种以原声（西班牙？）吉他为前奏，以小提琴、大提琴和打击乐为伴奏的乐器。这首歌的乐器分离允许大量细节涌现。音乐里的每一个乐器都可以被挑选出来并独立跟随，同时每个乐器都为混音提供了足够的细节来取悦耳朵。
"As for the pre-amp section of this unit? I was impressed. Hooking up a pair of powered speakers like the Kanto YU4s, the speakers pushed up the sonic quality ladder by a couple of rungs, adding a new even-handed sense of performance and a 3D effect around the central stereo image. Of course, the Kantos were hampered by their own inherent issues but the SGA1 still had them performing out of their skin, allowing these speakers to reach a level of midrange insight that they could only have dreamed about previously. What the SGA1 gave to the Kanto powered speakers was a sense of the lively combined with enough raw quality that allowed the Kanto speakers a real, skipping-through-the-daisies sense of fun. "
"As a pre-amp, the SGA1 is a valuable addition to any small footprint hi-fi system. It can lift other low-cost components to a higher level. Giving the system as a whole a sheen of quality. I wouldn’t buy the SGA1 purely as a pre-amp but it’s a great bonus for anyone looking for a headphone amplifier. "
"If you do run balanced hardwire though, well that’s a different story and the Soncoz is a wholly different beast in this mode. "
"When balanced mode was introduced, the SGA1 sprang to life and put on a real show. Detail and information now revealed itself upon a firm and solid foundation. The resultant tonal balance produced a seasoned and abundant soundstage that was full of individual highlights for the ear to pick out. "
"To confirm, as a headphone amplifier, I would only look to buy the SGA1 if you have a pair of balanced headphones and/or a balanced connection from your supporting hi-fi chain. Balanced mode provides a suite of sonic highlights and provides a top notch, mature sound. If you can go balanced, you’ll have a great time with the SGA1."