[dcs]

Hi folks,

Firstly, although I have posted very little on this forum, I would like to point out that I am a huge fan of Hugh's designs and philosophy and over the past few years have built three Aksa amps and a GK-1, incorporating them into a DIY three way active system which still causes me to grin like an idiot whenever I fire it up!  Three cheers for the man down under 

However, upgrade fever strikes again as I find myself with the opportunity to source a pair of Quad ESL 63s.  Having read back over several posts, I am rather confused as to the ability of Aksa amps to drive these speakers.  Posts made around 2004 indicate that the combination of Aksa and electrostatics is 'a bad thing', but Patrick in thread http://www.audiocircle.com/index.php?topic=29033.0 indicates that his 100N+ drives his ESL57s to "earthshattering levels". 

My real concern is not the levels obtainable from the speakers, but more that the highly capacitive load presented by the ESLs will drive the amp into oscillation and thus end up destroying a thing of beauty.  So I thought I might ask the panel (pun intended) for advice on whether Hugh's amps will be able to drive these capacitive monsters, and if so which versions (55/100 N/N+) would be best?

Cheers,
Dave

[raptor]

Hi Dave,

In the moved thread "New Aspen amp - naming ideas" Hugh said this:

"The 'Soraya' is actually a totally different amp to the Lifeforce, though there are some similarities.  It was designed to drive electrostatics, something it does better than anything else I've ever heard.  Loves naughty loads, beats 'em up, perhaps I should call it 'brat camp'!!"

Isn't it always the top of the range that suits us best    

[SuperMart]

Hi Dave,

I'm a Soraya owner and I have heard it drive a pair of Accoustats in another customer's system. The results were gobsmacking. The customer said that he had not heard bass of that depth and tightness before. The detail and delicacy were to die for and if the speakers were for sale I would have bought them on the spot. I'm in the queue for a pair of Hugh's new V Sonics I might add. I'm sure that the folk who popped into Hugh's room at RMAF would agree that the Soraya drove Dave Ellis's speakers to sublime levels - wish I could have taken home a pair of those, too!!

Hope that helps.

Cheers,

[AKSA]

David (Stocks in UK??),

I was apprehensive for some years, but since Patrick's experiments with Quads in NYC a couple of years ago and Alan Oldale's experience with the new Quad 988 (?) in NZ I've come to the conclusion that the AKSA is fine with electrostatics.

However, ain't it always the way, the phase shifts introduced by ES speakers which so discombobulate the voltage amp and precipitate oscillation in many amps are completely isolated in the Soraya, so this later amplifier is certainly my preference for driving ES speakers.

The big danger with ESs and the AKSA will be the very large drive currents, particularly at low amplitude where the SOAR of the outputs is threatened.  Anecdotally there is no evidence of any problem for the outputs, but I'd consider upgrading the fuses from 7.5A to 10A to be on the safe side, and I'd drive it at moderate levels, not too loud.  In any event, these panels won't go really loud, and if they do, you are threatening to destroy the panels rather than the amp, so do take it easy........

Cheers,

Hugh

[dcs]

Hugh, SuperMart and Raptor - many thanks for your replies. 

It's good to know that the Aksa is capable of driving the ESLs, but even better to realise that I've got a ready made upgrade path available with the Soraya.  However given the high WAF I think I can only get away with one upgrade at a time Hmm...

Cheers,
Dave (Smith in UK)