The thread is derivation form the previous thread about the Dima's amplifier.

I was trying to gradually approach better and better loudspeakers with the Zarathustra amplifier but today I decided to hit with the Zarathustra the pinnacle of low sensitivity, cone-boxed loudspeakering. Today I heard the Zarathustra was driving Wilson Audio Alexandria X2. I would omit to comment on some idiosyncrasies of Wilson Alexandria and some aspect of that particular installation but if to looks as the result only from the prospective of an amplifier (I heard Wilson Alexandria before 4 times with different amplifiers) then some things might be mentioned.

Generally the Zarathustra behaved unexpectedly well. With Zarathustra I eventually was able for a first time to recognize now phenomenal midrange could be with the largest Wilson and perhaps how weak thier lower bass… Previously I heard largest Wilsons with Lamms, Boulders, Spectral and Mark Levinson. Wilsons always did thier “large noble sound” and had all potency for handling the large violin groups. No other box speakers can handle it well at the larger volumes. The largest Wilson held it almost perfectly but not without stress. With Zarathustra it was insultingly beautiful! The harder I drove the speakers the more Zarathustra stepped slightly back when music reached the “questionable moments” and let the music flow no mater what. It was kind of interesting: it DID hold all necessary dynamic but sound did not step into the dangers water. At the same time Sound did all necessary “musical screams” with very-very reasonable amplitude.

For the sake of illustration I would call this effect a “selective compression”. The Zarathustra DID not affect the musical dynamic picks but slightly subdued the dynamic aggressiveness of the REPRODUCED LANGUAGE. This all-together give a certain feeling of softness and smoothness that was very much not expected from an amp, particularly from a SS amp that drives the speakers with Titanium tweeters.

I would like do not send message that dynamically Zarathustra has any compression. For instance yeastoday when Zarathustra was driving Kharma 3.2 this amps demonstrated 45732 times more micro- and macro-dynamic then the newest fraudulent Lamm ML2.1.  What I was describing in the paragraphs above was not the dynamic compression but some sort of “dynamic actions” that was presented within the sound of the amp. It was slightly different then the “dynamic viscosity” of Melquiades. Melquiades amps are way contrastier, more forceful, more violent, more belligerent and more contagious. The Zarathustra is slightly less aggressive tonally but it has own touch and own very interesting “intelligence”.

Now, I am writing all of this and I clearly understand that my views on Zarathustra form the prospective of Melquiades are completely inappropriate. I use Melquiades with 109dB sensitive horns, armed with really brutal and nasty drivers. The Zarathustra drove the mid 90dB sensitive boxes loaded with the drivers that require voltage of Hoover Damn to move them. The Zarathustra and Melquiades are really meant to works in totally different environments… I am saying it despite of the fact that the largest Wilsons are the ONLY speakers that do not sound like 95dB sensitivity. When I listen them I do not experience my typical “where is my dynamic range” frustrations…

Anyhow, I think I have finished to experiment with Zarathustra amp. To go into deeper analyses of the Zarathustra performance I would need a real seriously bult installation with some serious sub 96dB sensitive speakers. I do not know anyone around me who would be able to facilitate the level of the seriousness that the Zarathustra amp and my listing hobbits would require. The guys with “juts big speakers in a house” do not really fit the Zarathustra’s bill…

I will fix a low-pass filter at the Zarathustra’s input and will let it to drive my woofer towers until I will finish my Super Melquiades projects. Then I will see how Zarathustra’s bass will be able to compete with the single-ended 7Hz of the Super Melquiades. I will post the further findings…

Dima's Zarathustra made it over to my house yesterday fitfully escorted by the Cat on a fine cloudy humid and damp New England day. Having heard the original Melquiades I was intrigued what the amp was capable of and looking forward to its arrival, especially after seeing its Bride of Frankenstein looks from pix Romy had forwarded before his visit-both beautiful and ugly at the same time. What was of particular interest to me was knowing that the little Kharmas really respond higher powered solid state amps as well as what most people are familiar with pairing and have heard them with, lower powered tubes, usually Lamms or Tenors as demoed at the various industry shows. I wondered seriously how any solid state amp even with similar topology would compare to the superlative Melquiades. To say I was pleasantly surprised is a major understatement. The Dima deserves serious accolades for a job very well done. The amp has the directness and clarity of world class sets, and through the Kharmas projected a very large stage with a smoothness up top accompanied by an ease one would not EVER associate with solid state amplification and certainly not achieve with lower powered tubes. This created a widened the dynamic envelope of instruments than I have heard through these speakers. Just now it occured to me also that it has a lot of the sound of the very specifically pushed solid state amp, the DartingEel without the peakiness, leading edge (with an emphasis on edge) and thinness witnessed from those. Very much like the effect of a very smooth and neutral 100 watt SET. Cheers, Dima and hope we didn't disturb your sleep too badly with our crazed phone calls! Perhaps Romy will find someone with a more challenging load to test the outer boundaries of its dynamic capabilities. I for one am very interested in hearing the results...

I read the Owen’s observation and it strokes me that he was in a way correct: the Zarathustra does sound kind of strange and very much sonically it reminds a 150W 300B SET. It has some beauty, sweetness, liquidity and appeal at MF and in someway calmed but clean and not challenges HF.  What distinct the Zarathustra form 300B is it’s ability to handle LF all the way down (none of the single-channel SETs can do bass), the ability to do handle the real upper bass (300B has incorrect upper bass) and a certain “dynamic strangeness”.

Again and again I am trying to identify this "strangeness" and I would give you an association:

Pretend that you play volleyball but the floor of your volleyball court has an ability to move up and down very fast. Now pretend that your coach holding the remote control of the court’s floor and when he finds it necessary he accelerate the floor up or down. For instance when you jump to assault your coach speeds up the floor providing you with an extra velocity. Sometimes he instantaneously lowers the floor allowing you to handle an attacking strike ageist you providing you with more “damping”….  As the result - it creates a sort of vibrant, vivid and constantly dynamic environment where everything is moving and it is unknown where would be the efforts of your couch and where would be the efforts of your  own mussels. Whatever it is, but the eventual game’s scores is in your favor….

Rgs,
The caT

I give you an association: fat american with to much money and no brain sit in dreary shack by side of road trying to fill every desperate hour with something to give his life meaning.  He listens to half ass designs and declares them great using words like "dynamic strangeness" because is too stupid to understand what he hears and expects everyone else to agree with him or he deletes post. 

Does this person sound familiar Mr. Romy The Cat?

Ali Hassan

Ali Hassan wrote:

I give you an association: fat american with to much money and no brain sit in dreary shack by side of road trying to fill every desperate hour with something to give his life meaning.  He listens to half ass designs and declares them great using words like "dynamic strangeness" because is too stupid to understand what he hears and expects everyone else to agree with him or he deletes post.  Does this person sound familiar Mr. Romy The Cat? Ali Hassan

It is interesting: I am running now Zarathustra amp with my woofer towers, line-level crossed at 90Hz with fist order. Everything is very fine bass-wise, with very minute touch of dominating smoothness.  To my surprise the typical upper-bass harmonic thinness that all SS amp have do not manifest itself. Probably the 3kW transformers per channel and 2x100.000 caps do thier duty. Dima suggested that improvement in PS department would affect exactly upperbass, not necessarily the lower bass; it looks like he was correct. Some my local guys stopped by recently to listen my audio and they were surprised to see Lamm ML2 sitting not being even connected and the Zarathustra driving the woofers – the Zarathustra juts produce simply way better and more usable bass.

I kind of still have a feeling that Melquiades bass with 7H @full power transformer was more interesting.  Probably the more interesting bass quality of the Melquiades with that transformer was that it made possible for me to fashion my own bass. It was kind of freaky: when you use SET around 6C33C then an adjustment of plate current within 30-50mA hardly affect sound. With Melquiades armed with THAT transformer any minute adjustment of plate current, even within 5mA affected bass HUGELY and the change of current within 50mA totally “inverted” bass. That all took place at vicinity of 200mA while the transformer’s maximum current is 450mA. I do not know, when I build the Super Melquiades I would certainly see if Zarathustra bass would stay against the Super Melquiades. (The Super Melq. will have beside of THAT OPT the 1A/350V 100% duty power transformer and LCRC filter 10H-100uF-50R-10.000uF)

In any rate what Zarathustra does with bass is quite musical, tanks to it’s upper bass harmonic richness. I would say subjectively that it slightly more on soft side (isn’t it how it should be?)  but to say anything defiantly it would necessary to dial it with precision of 1/2-1/3 db per channel that I did not do yet.

Rgs,
The Cat

Chris,

when I got those large 7Hz-1kHz transformers I soldered one of them in my regular Melquiades and listed what it did. Besides all necessary bass benefits I decided to see how plate current would behave if I have no limitations for core saturations. My current gap is 200mA and while I moved with increment 15-20mA form 150mA to 250mA I could detect change in sound. Primary it has to do with discolorations and eating up the transient. The lower bass was changing but very insignificantly. However, when I connected the big trans then the tower become way more sensitive to even to 5mA. I would say that the drivers reacted like something damped them. I really do not know what is the reason. At the current Milq the power transformer is 350mA and the last cap 1000uF. I do not worry about it now and I am sure I will return to it when I will be doing the Super Melquiades

Also, I think I stressed too much (I was excessively surprised) the accent of my phrase “even within 5mA affected bass HUGELY”. I would correct it saying that the change current within 50mA affected bass HUGELY and the even change within 5mA affected bass auditably. In comprising with a “regular” 21Hz/200ma/9H transformer the semantic would be the following: change current within 50mA affected bass slightly auditably but the change within 5mA affected nothing.

Meanwhile this is the Zarathustra’s thread….. :-)