Tube Preamps...I'm sold

Got it!

I know Albert, who posts a lot here, will agree. He might spend days sorting out the right tube for each position in his preamps.

Certain things are not going to change though, for example, what a preamp is doing if it is designed with feedback as opposed to one that isn't, how well grounded it is, the quality of power supply regulation and the like. They all affect the sound.

But *your* point is taken too- just because you heard a tube preamp sound a certain way, does not mean you have heard what that preamp can really do if the tubes are not up to it. I have seen a reviewer install junkbox, outright defective tubes in a preamp, and then trash it in print when it didn't perform! Later the magazine announced that it would not publish a review if the tubes had been rolled.

One thing that is tricky for a manufacturer is the fact that modern tubes are often not up the quality of tubes from 40 years ago. Manufacturers have to buy tubes in large quantities, whereas an individual need only find enough tubes to populate his preamp. So- should the preamp be judged on how it sounds from the manufacturer or how it sounds if you can find the right tubes? In the words of Deep Thought- 'Tricky!'

On the subject of tube rolling, I recently changed out my stock tubes in my CAT signature with NOS GE Smooth plates and Russian Rocket tubes in the line section...BIG improvement. The pre-amp was no slouch before, but took on a new life with the swap-out. Far more realistic dynamics, more extension of both ends of the spectrum and less haze.
So, I am wandering how many people have actually heard what is possible with their pre-amp, certainly brings up the question of whether a reviewer has heard what a piece of tube equip under review can do.

Atmasphere, I sure hope you are talking about the MP1 when you mention the bottom octave, because the MP3 up against a BAT 31SE a couple years ago was severely lacking extension at both frequency extremes. Perhaps it was ill but it was a Mpls Atmasphere dealer demo. And the comparison was made at the Mpls BAT dealer and later on, my home. Upon switching from the 31SE to the MP3, the BAT dealer and I just looked at each other with total surprise as we never could have imagined the MP3 to have such issues.

Bart really nails it here on the significant improvements that are possible if the owner is willing to put forth the effort to investigate tube options. With some starting points as advised by Albert, I have taken the Aesthetix Io/Callisto and CAT UII and JL-3's to levels that transform these products far beyond their showroom performance.

Hi Jafox- must be that tube issue :)

FWIW, on the bench, the MP-3 has bandwidth from 1Hz to 400KHz in the line section- quite a bit wider than that of any BAT that we've seen.

The MP-1 has similar bandwidth, but has a lot more authority.

On second thought, the BAT dealer went out of business here some years back, before the 31SE came out. Our local dealer doesn't ship outside his area. So how did you do this audition comparison?