Tube Preamps...I'm sold

The demag device ran an audio waveform- not DC.

Hi Bart, I don't agree with you. Although our preamps are clearly affected by the tube choice, it is also evident that the preamp performs in a certain way- for example I can state with no qualms that our preamp plays the bottom octave better than other tube preamps on account of its direct-coupled output. It is also capable of greater detail since there is no output coupling capacitor to affect that detail.

That's not a thing affected by the tube choice. Additionally, tube preamps in fact do have coupling caps- (ours does, just not at the output). The choice of these caps has a serious effect on the sound of the preamp, again, not affected by the tube choice. Some preamps employ an output transformer, like the Shindo, they will have a sound peculiar to the operation of the transformer, again, not affected by the tubes.

Although tube choice can definitely have a big effect on the sound of a preamp, by no means are they the deciding factor on all preamps, though I don't doubt that there are preamps out there that simply don't shine until you get the right tubes.

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!'

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?

Thanks Jafox, for the explanation. The last I had heard, BAT was being handled by an outfit called Great Plains Audio, but googling them got a place in Oklahoma.

I've not had anyone describe the MP-3 as rolled off; I am guessing that something was up, but being that this was 5 years or more ago, hard to say what. Needless to say (although here I am saying it :) having a direct-coupled output on a tube preamp allows for some serious speed. At any rate there was some legal unpleasentness that happened a few years back; once I got that settled I was able to make some overdue improvements in the lineup. Its safe to say that any impressions made of our gear that long ago are not current, regardless of the impression.

BTW we are hoping to show a remote system for the MP-1 at either RMAF or CES...

Hi Sounds_real_audio,

Not balanced though, balanced means more circuitry which is what you don't like about solid state.

This statement is not correct. Balanced differential circuitry will not give the signal anymore complexity than single-ended if it is executed correctly. There is only the *potential* of complexity :)

We are working on a mechanical system for advancing the control...