is getting a tube pre a valid option with ss amp?

Hi Mjcmt,

I don't know if one can reasonably generalize about even a personal preference on type of tube based on a single comparison. First, type of tube chosen would depend not only on the designer's preference for the sound, but also circuit requirements, amount of gain needed, etc. The best tube is one that best fits the requirement of the component. Also, 6SN7s, like all tube types, have quite different sounds, depending on the specific tube chosen.

I have some familiarity with Cary triode amps (not the pentode EL34). They can sound dramatically different, depending on the 6SN7s used in the amp. Quite often, the 6SN7 chosen by the manufacturer is picked with cost and availability as primary concerns, not necessarily "sound" first (this makes sense because the amp has to be reasonably serviceable, and because "sound" is a personal thing, why put a lot of money into an alternative that may or may not be considered better by the buyer?). I've heard great improvement with alternative NOS 6SN7s used in their amps. Have you tried alternatives?

Realistically, one does have to audition stuff, with what comes from the manufacturer for the first "knock out" round of auditions. Unfortunately, that may mean eliminating a particular piece even though a better choice of tubes might have made it a contender.

If I were at a dealership that offered a preamp that uses something other than 6SN7s, I would still at least give it a shot, because, when properly used, the results can be terrific too. My phono stage, which I think is killer good, uses 12AX7s, but, I had to try quite a few different types to get to the ones that work the best, and sonic differences between types were substantial.

Adding a good, basic tube preamp will increase the presence and sound stage of your system. At one time I didn't believe that it would make any difference, but now that I have tried it, the difference is huge! I say basic because preamps with allot of bells & whistles have too much going on under the hood and they can dampen the sound. Look for a preamp that has as few tubes installed in it as possible- say 1 to 3 tubes, not including a tube rectifier if it's there.

Lamphear,
Please tell us why a tubed preamplifier with 3 tubes or less is preferable to others with more than 3 such as Audio Research Ref 3, Aesthetix Callisto, Atma-Sphere MP-1.

I'm very interested.

Because thats the type he makes or sells....just reaching here:)

More tubes are required if it's a line stage + phono preamp combo. That is the only exception. I have seen basic preamps with a single tube that work exceptionally well. A single tube, set up correctly has considerable gain. Most amplifiers have extremely sensitive, high impedance inputs. You may not know this, but preamps (line stage) attenuate the signal more often than amplify anything! An incoming signal of 0db to most amps would cause considerable damage to your amp, speakers AND possibly you in most cases. This is why passive preamps (with zero active components) work so well. So- if zero tubes/transistors works so well in the line stage, why should a preamp have multiple tubes? If there are tone circuits, etc.. extra gain stages are necessary. A basic preamp does NOT require a half dozen tubes give or take a couple.

To answer your question directly- If a design can work excetionally well with, lets say 5 components, why use 10? The individual who chooses to make a 10 component design isn't as good a designer. Complexity does not in any way prove an engineer is good. Designs that are complex when they don't have to be shows very poor judgement. If there are two machines and one has more parts in it than the other, yet they both work exactly the same, wouldn't you choose the machine with fewer parts? It's likely more thought went in behind the model with fewer components and it will work better anyway. As a last comment, devices with fewer compoents statistically break down less often.