Your emails stimulated this article.

You want to know why I don't write about tube preamps especially since I was responsible for a bunch of extremely high quality units that have become classics.

To give you the appropriate High-IQ answer that you deserve we must consider the state of the state,

Even back then in the 1930s it was well recognized that it was a tautological expression of the nature of audio circuits that they inhibited the full potential of tubes. The minute we connect a capacitor, wire, switch, inductor, or an output transformer, we modify the performance of the tube. What a joyous artistic paradox...distortion/limitation is implicit in all audio circuits.

The whole OTL shabang, which started in the 1930s, was an attempt to "get the iron out" to free the tube so that the output tube was freer to do its natural thing. Obviously in the 1930s "radiomen" knew that the rise time/bandwidth of every audio circuit was being limited by all of the input transformers, coupling capacitors, output capacitors or transformers.

Over the last two decades the art of tube preamplifier design has significantly advanced most because of the integration of low noise/ultra low impedance solid state regulation. In a world that was black and groovy and moved at 33 rpm phono..meaning tube preamps were essential and the race was on and New York Audio Labs competed and won awards.

But that was then and this is now and this now is a digital world for most..and it is a world of much higher refinement.

I have now answered the above question.

We demand a much higher level of refinement in our audio circuits because we can. Colorations and discombobularities that were once acceptable…because we didn't know any better…and now verboten.

My conclusion is simple: they add a great deal of unacceptable colorations…squeeze down my aural matrix and pollute a great deal of the natural harmonic rightness of DHTs.

If we ask a signal to pass through more tubes, more wire, more switches, through more printed circuit boards, and be modified by more power supplies, we should expect more of what we don't want.

DEALING WITH THE OUTPUT STAGE OF CD PLAYERS

Much of the coloration we don't like in digital audio is directly related to what we abhor in solid state preamps the sound of small signal transistors…but they are a fact of life and they have one significant benefit that can be exploited…their low output impedance.

If your CD player has a volume control it is helpful.

If you CD player doesn't, you need to get a high quality passive volume control.

This the way to connect all of your equipment: You must have the cables between your CD player, and your amps, or the passive volume control and the CD player/amplifiers as short as possible..no more than two feet,

Of course the best strategy is to have your amplifiers as close as possible to your speakers, and there is nothing wrong with your CD player being in the middle of your speakers.

This naturally implies that the longest cables in your system are the speaker cables..BUT..try to keep them as short as possible.

Same rules apply: Keep the interconnect cables as short as possible. If you can get away with it..nothing wrong with them being only inches long…because as you know, we can hear the differences in just a few inches of cable.

This, the most important question, can only be answered in the context of the refinement of your aural matrix…which is your musical consciousness manifested through your gear.

If you have a tube preamp experiment with it out of your circuit, and listen to what happens.

There are more and more high quality stepped attenuators available, and your search engine will help you find them. These high quality volume controls are not cheap…but they never become obsolete.