O.k., I've not posted a review thread before so go easy on me. 
Short history to acquisition:
I tried some Apuresound ([AK]Zip ) RCA-2-RCA interconnects (thanks to Juzmister) in place of the Stax OFC ones I'd used for years. They revealed that I could benefit from upgrading my amp (Stax SRM-T1, unmodded, sorry Spritzer) to then fulfill the potential of my HE60s. And so I'm now moving just one upgraditis step - yes, just one, really (why don't you believe me???
) - further to find that synergy of ideal sound (for me). I couldn't afford Alex's ([AK]Zip's) ES-1 or his final maxxed KGBH so I took his suggestion to look for alternatives in the 007t price range and ran straight into Adrian's (akwok's) sale of his Woo Audio GES.
Equipment Used:
For these impressions I have used a variety of redbook CDs (rock, jazz, folk, orchestral, studio and live) and a StatMat CDi Blue (Thanks to fkclo) through a modded Pioneer PD-S901 stable platter (or a Musical Fidelity A3.5) via a pair of VH Pulsar interconnects (Thanks to happyangryhappy) through the Woo Audio GES to the Sennheisser HE60s reterminated with a Stax Plug (Thanks to [AK]Zip). The impressions come after a few days settling with the GES and a solid day's listening with the above equipment (the interconnects arrived today).
Detail:
The first point to note with the GES is that it takes a good hour to warm up - it's disappointing listening to it prior to this. In fact if you start listening too soon to the amp you'll find yourself driving the volume up too high and the sound is unbalanced, most noticably the poorer the source recording you use, but annoyingly noticeable even with the best recordings.
Of note, though, is that it warms up faster with signal going through it (i.e. listening after an hour of passive warm-up - just having had it turned on for the hour - it is initially still not at its best but it comes into its own within a further 15-20 minutes of active listening). You notice this by where you need to place the volume control as it reaches its prime operating temperature - it gets louder and louder until it's settled. For instance, if it's not fully warmed up I'll play my better quality recordings at 1 o'clock but once it's warm these are too loud (for me) beyond 12 o'clock. Once warmed I'm generally playing my various recordings anywhere between 11 o'clock and 12 o'clock.
For an electrostatic amp it's quite lively; dynamic. And, yes, I concur with others who have stated that it packs its best punch when you give it just that little bit more volume to truly 'drive' the phones. This can become a juggle, though, as driving the bass punch sufficiently can lead to an occasional 'punch' of too much treble (for me, at least). Which is probably why Kevin Gilmore went on to the KGBH design to give more bass slam
. For this price range, though, it's a very good result. 
It's definitely addictive - seductive? - the longer it's on, the more you listen, the longer you want to listen.
The bass is strong - powerful, clean and clear. Yes, it does give the HE60s good bass - if there's good bass recorded on the source, of course!
Sweet, crisp treble - cymbals are cymbals, punchy, dynamic with delightfully realistic decay. It's so much closer to the sensation of being there, at the
recording.
It makes the HE60s truly sing, using their full breadth and scope. It produces great dimension - soundtstage front to back, left to right is reflective of
what each source delivers (the Musical Fidelity is more constrained than the Pioneer, and works better with broader scope orchestral recordings whilst the Pioneer delights in close microphoned works).
The GES retains the detail - the distinct placement of instruments and voices within the mix (especially wonderful on multi-voice choruses and well mic-ed choirs) - but is not hard or harsh in its analysis - it's still warmly musical, seductively so. At times I get too analytical myself and wonder if I'm
missing something, only to relax back into the music that's being so well produced by this delightful amp. It's just a good, neutral and clear deliverer of what it's being fed.
Now I know I've rattled on about sound/music and there are a number of HeadFi-ers for whom look is also an issue. I'd only advise going to the Woo site and checking out the images there. They're a true reflection of the simple, well polished, rounded look to this typical open-tube amp. Of course the best look is in the dark, with just the source and the amp as the light sources: only regret is that the front tubes don't glow anywhere near as brightly as their larger partners
. As if that matters - this thing's for music! Listen to it!
Summary:
Does it do the job? A resounding 'Yes'. Give it a good quality audio signal from a good player playing a good disc - through a good quality interconnect - and it will deliver everything it gets, evenly and delightfully amplified to your chosen electrostatic headphone.
What it brings to my audio experience, though, (pending the arrival of my [AK]Zip interconnects) is completeness. [AK]Zip interconnects will (finally)
complete my main system and, thus, what I'm noticing more nowadays is not "there's something I haven't heard, or heard that way, before in that recording" but more just recognising that my main rig is delivering everything I can hear out of my recordings and then, paradoxically, noticing what isn't delivered by my bedside or portable rigs. Oh, the sacrafices!
Cest La Vie!
Best: Once it's warmed up and my headphones are on my head then that's the way I stay (provided I don't run out of discs within reach!). Food, Drink and other physical necessities like sleep just have to be put on hold!
Worst: Single Volume Control (no opportunity to alter balance if you ever needed to - not that I ever have with my previous amps that had this feature); Only one Stax 'Pro' outlet unless you order more outlets; Source selector switch at back of amp (would be easier on the front as with other Woo amps). Perhaps, for those wanting to eventually go balanced the option of balanced inputs/outputs might be desirable (I'm not sure if Jack is able to offer it with this amp?).
Further upgrades? Well, I'll be interested in suggested tube upgrades but, like mikeg, I'll wait to see which tubes are found to be best by others.
Short history to acquisition:
I tried some Apuresound ([AK]Zip ) RCA-2-RCA interconnects (thanks to Juzmister) in place of the Stax OFC ones I'd used for years. They revealed that I could benefit from upgrading my amp (Stax SRM-T1, unmodded, sorry Spritzer) to then fulfill the potential of my HE60s. And so I'm now moving just one upgraditis step - yes, just one, really (why don't you believe me???
) - further to find that synergy of ideal sound (for me). I couldn't afford Alex's ([AK]Zip's) ES-1 or his final maxxed KGBH so I took his suggestion to look for alternatives in the 007t price range and ran straight into Adrian's (akwok's) sale of his Woo Audio GES.Equipment Used:
For these impressions I have used a variety of redbook CDs (rock, jazz, folk, orchestral, studio and live) and a StatMat CDi Blue (Thanks to fkclo) through a modded Pioneer PD-S901 stable platter (or a Musical Fidelity A3.5) via a pair of VH Pulsar interconnects (Thanks to happyangryhappy) through the Woo Audio GES to the Sennheisser HE60s reterminated with a Stax Plug (Thanks to [AK]Zip). The impressions come after a few days settling with the GES and a solid day's listening with the above equipment (the interconnects arrived today).
Detail:
The first point to note with the GES is that it takes a good hour to warm up - it's disappointing listening to it prior to this. In fact if you start listening too soon to the amp you'll find yourself driving the volume up too high and the sound is unbalanced, most noticably the poorer the source recording you use, but annoyingly noticeable even with the best recordings.
Of note, though, is that it warms up faster with signal going through it (i.e. listening after an hour of passive warm-up - just having had it turned on for the hour - it is initially still not at its best but it comes into its own within a further 15-20 minutes of active listening). You notice this by where you need to place the volume control as it reaches its prime operating temperature - it gets louder and louder until it's settled. For instance, if it's not fully warmed up I'll play my better quality recordings at 1 o'clock but once it's warm these are too loud (for me) beyond 12 o'clock. Once warmed I'm generally playing my various recordings anywhere between 11 o'clock and 12 o'clock.
For an electrostatic amp it's quite lively; dynamic. And, yes, I concur with others who have stated that it packs its best punch when you give it just that little bit more volume to truly 'drive' the phones. This can become a juggle, though, as driving the bass punch sufficiently can lead to an occasional 'punch' of too much treble (for me, at least). Which is probably why Kevin Gilmore went on to the KGBH design to give more bass slam
. For this price range, though, it's a very good result. It's definitely addictive - seductive? - the longer it's on, the more you listen, the longer you want to listen.
The bass is strong - powerful, clean and clear. Yes, it does give the HE60s good bass - if there's good bass recorded on the source, of course!
Sweet, crisp treble - cymbals are cymbals, punchy, dynamic with delightfully realistic decay. It's so much closer to the sensation of being there, at the
recording.
It makes the HE60s truly sing, using their full breadth and scope. It produces great dimension - soundtstage front to back, left to right is reflective of
what each source delivers (the Musical Fidelity is more constrained than the Pioneer, and works better with broader scope orchestral recordings whilst the Pioneer delights in close microphoned works).
The GES retains the detail - the distinct placement of instruments and voices within the mix (especially wonderful on multi-voice choruses and well mic-ed choirs) - but is not hard or harsh in its analysis - it's still warmly musical, seductively so. At times I get too analytical myself and wonder if I'm
missing something, only to relax back into the music that's being so well produced by this delightful amp. It's just a good, neutral and clear deliverer of what it's being fed.
Now I know I've rattled on about sound/music and there are a number of HeadFi-ers for whom look is also an issue. I'd only advise going to the Woo site and checking out the images there. They're a true reflection of the simple, well polished, rounded look to this typical open-tube amp. Of course the best look is in the dark, with just the source and the amp as the light sources: only regret is that the front tubes don't glow anywhere near as brightly as their larger partners
. As if that matters - this thing's for music! Listen to it!Summary:
Does it do the job? A resounding 'Yes'. Give it a good quality audio signal from a good player playing a good disc - through a good quality interconnect - and it will deliver everything it gets, evenly and delightfully amplified to your chosen electrostatic headphone.
What it brings to my audio experience, though, (pending the arrival of my [AK]Zip interconnects) is completeness. [AK]Zip interconnects will (finally)
complete my main system and, thus, what I'm noticing more nowadays is not "there's something I haven't heard, or heard that way, before in that recording" but more just recognising that my main rig is delivering everything I can hear out of my recordings and then, paradoxically, noticing what isn't delivered by my bedside or portable rigs. Oh, the sacrafices!
Cest La Vie!Best: Once it's warmed up and my headphones are on my head then that's the way I stay (provided I don't run out of discs within reach!). Food, Drink and other physical necessities like sleep just have to be put on hold!
Worst: Single Volume Control (no opportunity to alter balance if you ever needed to - not that I ever have with my previous amps that had this feature); Only one Stax 'Pro' outlet unless you order more outlets; Source selector switch at back of amp (would be easier on the front as with other Woo amps). Perhaps, for those wanting to eventually go balanced the option of balanced inputs/outputs might be desirable (I'm not sure if Jack is able to offer it with this amp?).
Further upgrades? Well, I'll be interested in suggested tube upgrades but, like mikeg, I'll wait to see which tubes are found to be best by others.
. So when the GES fitted my requirements I grabbed it. No regrets, whatsoever. Just got to recover some of the funds by making the SRM-T1 available for another to enjoy. 
