[Frihed89]

The SS version I heard was the best-sounding head amp at RMAF, to my ears. Some guy kept handing me different cans (I can't remember all the names). It sounded supurb with all of them. I did not hear the Hybrid version although I was shown the boards. The Eddie Current amp with OPTs was the next best with the new (and as yet unreleased) Audeze cans.

Wo is me. There wasn't enough wrong with my SP MPX3 Slam SE to warrant buying a replacement head amp. However, I did upgrade my SBH with a custom cap pack and new output modules. (I have 2: one for the head amp + one for the preamp).

 

[pabbi1]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif Nice work (very clean and intelligent routing of the wiring), congrats on the completed amp and chassis Pabbi. The wood casing is very cool indeed. Our musical tastes are very similar going by your play list. What volume pot did you use ? Looks like a Gold Point but I can't quite make it out (my eyes are getting old and tired ) Peete.

The attenuator is an Acoustic Dimensions 41-step Ladder - not cheap, but a good match for this amp. I have struggled with attenuator selections over the years, and have used Goldpoint, TKD, Noble, DACT, RK40 (miss them), and a variety of Asian origin steppers, and this is a great match for a high resolution amp.

Had I not lucked into a DIY version (rare one off event), I'd have probably used dual TKD 2CP-2511.

 

[les_garten]

Quote:

Originally Posted by pabbi1 /img/forum/go_quote.gif The attenuator is an Acoustic Dimensions 41-step Ladder - not cheap, but a good match for this amp. I have struggled with attenuator selections over the years, and have used Goldpoint, TKD, Noble, DACT, RK40 (miss them), and a variety of Asian origin steppers, and this is a great match for a high resolution amp. Had I not lucked into a DIY version (rare one off event), I'd have probably used dual TKD 2CP-2511.

That's a beautiful attenuator for sure. I'm considering an alps in shunt configuration. Did you consider doing a lesser POT in shunt configuration?

 

[pabbi1]

Not really - shunt ain't working out real well for me on another project. I prefer paying the $$$ for a sure connection, and, fewer variables. Not at all saying it isn't a good path for others, just another complexity I can do without.

 

[Frihed89]

The Shalco ladder attenuators that Blue Circle uses are nice, but expensive.

 

[studeb]

I have a ss beta build, i have posted some comments on the amp in the build-a-beta thread. I have no input pot, using it as a traditional amp.
This is a good amp. Is it a great amp? i do not know, i only have SRX-mk3 to listen with, so i cannot comment on its ability to handle the top flight cans. I do have a Rat Shack step up box and a stock T amp. It is better than that combo. There is better bass, but the T amp is not really a bass head amp is it, the top end is not as grainy, and the mid range is better. I have to plug my tube amps in to compare to this amp.
Lately my life has been "where did that bass line come from?" That is what happens when you go from bookshelf speakers to floor standers. The same thing happens when i turn this amp on. Kick drums become well defined, the upright bass has life and air to it. I do not get a lot of sizzle, zing or sibilance here. Cymbals are cymbals, not bits of alu rattleing in a box.
Can this amp do rock? Yes, i can't comment on death metal or thrash. It has low end speed, slam and control. All you need to handle traditional rock. Geddy Lee actually sounds like he can sing, that is how good this amp is. I think you will also find that you listen to music louder than before because, as others have mentioned, it is very clean.
What about acoustic? Not a problem. There is enough control for spatial clues to get through. Don't ask me how big the isolation room is, but on live tracks, the audience is erily spread out. Stringed instruments have a resonant body and very nice tone to them. I also notice background bits that were prviously lost in the mix, background voices in Levon, and i do not remmeber hearing "give peace a chance" in All Good People before. I do need to sit with it with more classical, i just have not had the time to sit for extended periods with headphones.

Like others I find it very hard to find a negative aspect of this amp. I wish i had some top flight cans to run with it, would they reveal a shortcoming?

If you are interested, track one down. I do not think you will be dissapointed in it.

System:
Magnavox CDB 650 > Perpetual Tech P-3A (via I2S) or Grado SS > Dyna PAS3 > B1 > eXStatA

Music:
All over the place.
Yes - The Yes Album
Rush - Permanent Waves
Poems for Laila - Poems for the 20th Century
Elton John - Madman Across the Water
Cowboy Junkies - open road
Harmonium - Self titled
Handel - Messiah (its Xmas, right) Boult/LSO Westenberg/Musica Sacra
Grofe - Grand Canyon Suite
Max Roach - Deeds not Words
BNL - Snacktime

 

[Currawong]

Thanks for the reviews. With any luck I'll be able to compare it to a variety of Stax amps once I've built mine.

 

[HeadphoneAddict]

So, while wiatrob preps my amp case and Sherwood's case, this past weekend I borrowed his prototype case with the new tube boards and PSU installed. So, it has the same front/rear panels and attenuator as at RMAF in October, but new guts. I plugged it into my Apogee mini-DAC XLR with a pair of ALO SXC 18g IC, and a halfway decent tributaries power cable, feeding it from a Samsung DVD player via Synergistic Research Coax cable - and the sound is out of this world with my HE60 and O2 Mk1.

The sound is rich and full and immersive, very fast and detailed, imaging is very precise, and timbre and tone is spot on. Soundstage is much better balanced, and at RMAF it was much bigger than with my old GES. But at RMAF the GES had much better timbre and tone and frequency response. This is now clearly better than the prototype at RMAF 3 months ago, and I don't know if the difference is better synergy with the Apogee than with the PS Audio DAC, or the design changes, or both. The eXStatA at RMAF was clearly better with wiatrob's OPUS DAC than with my stock PS Audio DLIII, but I don't remember it being this detailed and spacious as it is with the Apogee. The one at RMAF was also the sand version, not the tube version.

Anyways - if this was a production amp it could command $1500, possibly even $2000 per unit. I was stunned as I was comparing it to my WES and figuring that the eXStatA could fit right between my GES and WES in sound quality and performance. I can think of no higher praise than this -> if the eXStatA was my only electrostatic amplifier, I could live happily with it and not be thinking about upgrading (for a while). The WES is still more euphonic with a more refined texture, a little more engaging in the mids, with a little less edge to the treble, but it's hard to believe you have to spend 10x as much for those small refinements.

There is NO WAY we can let this die out and not see more being built for many years to come. If there aren't more boards made after this next run and this is goes away, 5 years from now people will be selling these for the price of an HE60 and wondering why they aren't made anymore. It would be just as bad as no more R10, HP-1000 and PS-1, or L3000 and K1000. There will always be a demand for an amp like this, just as there is for the vintage discontinued phones.

ALEX, I don't care what the other naysayers and fanboys of other amp designs say, but we need to throw you a party and ship you another round of free headphones for designing this amp and seeing it through this far! Bravo! (I was so excited I had to call Bill 3 times to tell him how it sounded)

 

[sergery]

eXStatA Review:

I have had the headphones literally glued to my head since this past friday afternoon when I got my headphones - the quality of music coming out of this amp is that rewarding. So let me quickly lay out what I have been listening to:

Chain:M-Audio Firewire Audiophile-> AMB Gamma1 -> eXStatA -> HE60

Music:Wide variety of music. Just a sample of the music I have listened to recently that has sounded great on this combo:

Faith No More
Tool
Amon Tobin
Martinu
Mahler
Bjork
Radiohead
Massive Attack
Flying Lotus
FSOL
Fantomas

Soundstage: Medium sized, intimate but not too cramped. Voices/instruments location is natural. Not super tall, but some height distinguishability. Very 3-D, frequent wrap-around the head effects and good depth portrayal.

Tone:
Highs hang in the air and blow away into the breeze, bells chimes and cymbals sound like they are being coupled directly into your eardrums courtesy of HE60

.

Mids are silky and good singers are a treat. I have been listening to Patton and Bjork on repeat. Likewise string instruments have such amazing texture that the hair stands up on the back of my neck.

Bass impact is outstanding on these phones. I really was not expecting to prefer them to my DT770's in this respect, as I feel that phone when eq'd provides a complete representation of the frequency spectrum. However, these have all the slam I could ask for - I literally had to turn the amp down when my right eardrum got stuck inside-out

rofl.

Presentation:Ok so it is impactful, but that is not just some bulldozer or godzilla trampling around. The bass portrays amazing textures in unison with the mids and the airy highs that leaves an amazing 3D picture that is hard to tear yourself away from. I alternate between searching for music in my collection that has amazing textures or amazing ambiance/soundstage (or both). I had to trick myself with cookies to stop last night!

Conclusion:Are you still reading this and not either A) plotting a way to get more boards made or, b) making this amp?? Seriously though I feel that for the cost of the build, and the simplicity, it represents a serious value sonically. I would like to thank Alex Cavalli, EricJ and the rest of the design team for making this amp a reality.

Cheers!

-Serge

 

[jp11801]

In a few days I'll post some impressions of the eXStatA amp that Pabbi1 graciously sold me. Needless to say I am incredibly happy with the amp and it sounds wonderful. The amp produces sounds well past its price class and if I had to quantify the sound calling the BHSE a 10 I'd have to give the eXStatA a solid 8 which is a serious triumph in my book. The 404le and eXStatA is a match made in heaven and it ain't bad at all with the O2's.

This is no real surprise to me as the stacker ll dynamic amp design is a marvel of dollars to sound quality as well.

 

[nsx_23]

I need one of these in my life.

 

[the_equalizer]

Quote:

Originally Posted by nsx_23 /img/forum/go_quote.gif I need one of these in my life.

x2. I want to try out an electrostat setup so badly... I've been resisting hitting the 'Buy Now' button since last november...

 

[gilency]

Don't resist it... the sound is well worth it. I have one of Pabbi's builds and the sound is just wonderful.
I just hope Mr Cavalli orders a few more rounds in the near future.

 

[dBel84]

I have been meaning to get around to posting in this thread but it is hard to admit to myself how good the amp sounded and at the same time acknowledge that I opted not to build one - life

I initially heard the Exstata in it's early prototype phase. The basic premise was a comparison between the SRM717 and the Exstata as well as comparing the ESP950 and the O2. Needless to say, I was left speechless by that little exhibition as it challenged many preconceived ideas I had about the O2 as well as the idea that the SRM717 was one of the best matches for the O2s.

I then got to hear the latest incarnation of the Exstata with the 404s more recently, one of the most attractive Exstata builds imho

and a nicer pic ( scrounged from another forum )

There are so many variables to compare but I will keep this brief and to the point.
1. The exstata can drive the O2 without a problem, and enables them to deliver such godly music that it leaves you wondering if you could ever go back to any other type of music reproduction. ( I had sworn off all headphones except the orthodynamics )
2. The ESP950 is a force to be reckoned with , highly underrated and superb value for money
3. The 404 which has always been a pleasant acoustic experience with no real bass turned into an invigorating and shockingly real musical experience. I had the benefit of it being connected to my source and I had my music along so I could get a real feel for the amps capabilities and it is a top performer on all fronts. It slams out bass with speed and depth like I had only experienced with some of the big orthos and another cavalli amp. The imaging was perfect and it had kept magnificant control of the 404. I had heard the 404 sounding edgy in the past, not this time and I ended up spending far more time with it than I had anticipated.

Bottom line, when I eventually do take the plunge into the stat world , I will hunt down the designer and extract a board or 2 from the depths of his coat pockets

Thanks Alex, it was a real pleasure to listen to this amp ..dB

 

[Jon L]

Quote:

Originally Posted by dBel84 /img/forum/go_quote.gif

Is that the SS or hybrid version?