Best amplifier for Acoustat 2+2 electrostats for holographic sound, or change speakers?

A description of what Holographic Sound as term means to yourself would help as it is widely used to mean a variety of perceptions for a presentation of the end sound.

I have attached a few description given by others on their take on Holographic Sound.  

(1) "Holographic means that the music isn't rooted to the speakers, but instead seems to be originating from specific areas where the musicians and singers are arranged throughout the soundstage of your listening room -- especially between and outside your speakers -- in the best cases, there is air between them and you can imagine some closer to you and some further away -- the proverbial deep and wide soundstage. 

But, holographic means the musicians and singers appear throughout the soundstage almost like holograms."

(2) "My definition would simply be different words than those used above. I think "holographic" is more of a situation where the illusion becomes believable and almost touchable. Whether it is a soundstage (sonic holograph - nice term) or visual field (hologram), the specific event takes on an atmosphere of real volume and space."

(3) "I think 3-dimensional sound has more in common with multi-channel home theater set-ups, which can provide the most easily heard holographic situations. Surround sound would then be the engineered product of sounds delivered in specified areas. These sounds are what I enjoy as the novelty of special effects."

I myself use a Stacked Array of Electrostatic with 845 Monoblocks Power Amp's.

Upstream of these I have used a variety of Pre Amp's and brought in a large selection of Phonostages and even more SUT's, along with a Head Amp to make the most of the Vinyl Source.

For the Digital Source, I have been less adventurous, a Bespoke Built DAC using Valves in the Output Circuit along with a CDT, has offered a very good impression in the home system and performed exceptionally well alongside much more expensive Digital and Vinyl Sources when used in other systems.

When I get a better understanding of your description of Holographic Sound I will add more, as I have been able to create the perceptions that are a version of what is described above, and I believe beyond what is described above. Especially when it comes to the 'Envelope', there is a perception that can be generated in the listening space, especially a listening space that is seemingly expansive, voluminous.

In such a perception of Spaciousness, there is also another perception to be encountered, where the Imaging of a performer is perceived as being locatable in the space, when the perception of the performer has embodiment, there are other perceptions that are possible to encountered as follows.

The 'Envelope' is where the produced Notes and Vocal produced take on a perception of their being formed, the Note/Vocal has its own embodiment, as it seems the Imaging has further layers, where the performer is visualised creating the sound being produced. 

It is when the End Sound and Psychoacoustic Affect attains this level of perception that the following perceptions really are discernible:

Attack – the time line for the note to being audible to attaining  maximum volume.

Sustain – Once the perception of maximum volume is present, the length of time it remains.

Decay – The life of the Note / Vocal its length of time being perceived before if expires.

 All the above is achievable as perceptions to listeners on Stacked ESL's almost 60 Years since their being new.   

As an alternative suggestion to having to buy into alternative Power Amplification.

I am very very familiar with the Nelson Pass Design Korg B1 Pre Amp.

If the gain of this Amp will work with the Power Amplification, for the money required to acquire the Basic Model, there is a lot on offer.

I have mainly heard it in use across a Variety of Power Amp's, both SS and Valve, but nearly always with ESL's.

I have also heard the Basic Design having undergone some of the now known upgrade tweaks, different Cap's, VC.

All build guises demo'd,  have delivered to what I class as my preferred description of Holographic in the earlier post.

As a trait, the Korg B1 will tighten up the lower frequencies, where a Bass Decay is with a defined edge and not lingering. Such a control of this frequency, enables the Mid's and Highs to be improved in their presence. The overall frequency range is much improved in coherence.  

The Envelope developing, is something that gets worked towards by improving interfaces in general throughout the audio system. The magic bullet to attain this, is perseverance and willingness to try out different interfaces, as time goes by things discoveries are made that are wanted to be maintained, where there is no want to return to what was before.      

I have heard Microphonic and I have heard the measures put in place to control the audible effect.

When controls are in place, there has been nothing present for any length of time to cause any concern.

The Pre' has made such an Impression on myself used as loaned models in my system, I have purchased Bespoke PCB's with a option to have oversized components added, there is plenty of real estate.

There is also Bespoke Built VC's to be used with the Monoblock Balanced Pre' I am having Built.

The Casing is to be Airtight P'holz and the Nutube will, as an additional measure  be embedded into its own P'holz Sarcophagus.

A selection of the local HiFi Group, as result of the Nutube DHT experience, are now experimenting with Tube DHT Pre Amp's. Speakers being used are Active Cabinet, Passive Cabinet, Horn Loaded Cabinet and ESL. 

I was given my first experience on Wednesday morning in a very well known system, where the CD Source > Valve DHT (gain matched) to a Neurochrome Power Amp > Passive Cabinet Speakers .

This was the best I have heard this system being driven by SS Power Amplification.

There is also a Design coming together to modify the Valve DHT, something about the methodology for heating/driving the Tubes. 

My visit to this home prior to this visit was listening to the System via a Heavily Modded SP10 (Bespoke Speed Control / Platter Bearing Overhaul) > Bespoke Built TA > Newly Refurbished AN IO > Heavily Modified design for a KB1 (Three Box with - Blackgate Cap's - Bespoke VC)  > 300B Power Amp's.

Hearing this set up in use was also an indelible experience. The new encounter with Valve DHT and SS has been quite different as an impression made, but both are equally indelible.

The time will come when everything is modded to its end point, and the side by side comparisons will commence. 

Note: When the EE goes down the path of modification, the Base Model is maintained and Modification Models are built from scratch, these are then easy to discern where the Plus/Minus points are discoverable.