Since I was wondering at Soundstage site I come across Marc Mickelson review of Einstein preamp.

http://www.soundstage.com/revequip/einstein_the_tube.htm

I am not familiar with this unit and but there was in there something that “attracted” me in this preamp – primary the Moronity of its objectives. According to Marc Mickelson:

"Only nine of the unit's 19 tubes are used for the main line-stage circuit…. The other ten tubes are used at The Tube's inputs -- five inputs, one tube for each channel. Each input has its own separate self-contained circuit, none of which is inactive or out of the preamp's main circuit.… Instead of the selector switch choosing which input's signals are routed through to the outputs, it instead turns on the heater supplies of the pair of tubes for the chosen input….”

I perfectly understand the implementation. It is arguable what would be less harmful for sound: one line-level switch in a signal path of 5 grids and 4 anode connected in parallel to a “hot” grid and anode. I personally feel that a single switch is better as ANYTHING touches control grid is SUPER sensitive; however it is not the point of my post.  What is the point of my post is that I see no point to have a dedicated tube for each input. Mark Mickelson expanse the advantage as:

“it allows experimentation and fine-tuning like no other preamp. You can pick the input tubes that sound best for each source. “

Well, this is exactly what I against religiously! It is NOT THE PURPOSE OF A PREAMPLIFIER to inject into sound different colorations to mask out the imperfections of the previously located components. By enabling users to do pick the tubes for different sources and putting into the initial design those objectives it is indication that ether the designers were Morons who had no idea what they do or the unit meant to be used by Morons.

A preamplifier should be absolutely transparent and it is THE  OBSOLETE MANDATORY MINIMUM for any preamp:

http://www.goodsoundclub.com/TreeItem.aspx?PostID=2589

If a pram has a provision to change its sound for each source via tube rolling then… why to stop on the input tube roiling? Why would not have a loop inside of the prams where the signal go over another couple stages with different sound tubes? How about an Equalizers. How about a compression Extender? How about a couple of SS stages and a stage with vintage oil capacitors? How about the pentodes? How about the stages with different type of bias?  they all have different sound!  What is it: high-end Audio or the Audio Retouching Anonymous?

I really see that the Einstein’s idea was VERY faulty… if it was the Einstein’s intention. It is very much possible that the tubo-self-entertaining WAS NOT the Einstein intention that they pursued the given topology because of other considerations…. However, I never heard in this review about “other considerations”.  For what it said, it sounds to me like another typical-bogus “beloved by special people” preamplifier…

Wojtek, a preamp should care absolute transparency not because I said it or have warren somewhere within my site but because it just makes sense, doesn’t it? I undusted what you ask but I also undusted why you asked it. The key is that you do not understand what “X-factor” is. It most likely came from the fact that you apparently never experience “X-factor” and therefore you attributed to “X-factor” some things that have no relation to the “X-factor” (SS buffer, oil cap, silver wire and the rest crap…). If you feel that “X-factor” is a properly of some kind if colorations then you are mistaken. The “X-factor” in fact has ABSOLUTELY NO RELATION TO TRANSPARENCY and therefore I do not see any conflict if an absolutely transparent line-stage has or do not has the “X-factor”.

Try to “get” it. The “X-factor” is not juts a term that invented in order the others to characterize whatever they feel should be called as “X-factor”. The “X-factor” is VERY SPECIFIC impact to Sound that took place in Lamm L1 and L2 preamps.  If you did not A/B even a signal channel with L1/L2 in path and bypassing it then you hardly have business to use the phrase “X-factor” and it most likely you have no idea what it is all about. BTW, 90% of people who did used L1/L2 still have no idea what “X-factor” was and what those preamps could do. Still, pay attention that L1/L2 are very much NOT TRANSPARENT preamps…

Guy, I am not sure that “all audio components would ideally be transparent” as most of the audio components perform own actions: gain change or different type of conversions. Preamp, in contrary, mostly performs no actions or if it is in unity gain it has no actions. Also, is all depends what it is your definition of transparency. To view transparency as a delta between output and input is VERY simplistic thing as there is much more evolve perception of transparency. You complain that you yet to hear any audio components that completely transparent. Well, take a two resistor of good quietly (RH60 for instance) make 6dB voltage divider, preserving your input impedance and place the divider right at input of any of your component. Now you will have a function performing components that has absolutely no affect to transparency. If you wish to assess more complicated components then try Placette Active preamp. From where I stay I was able to find any influence to transparency in this unit. So, it is accomplishable. The problem that I see that people do not trying to pursuit it.