If you had to choose: tube amp or tube pre-amp?

You're right Charles, the topic started to deviate...but this been extremely helpful. So it sounds like I'll start with the tube pre over an amp!

The last thing I'll ask, when I select a pre-amp are there any factors I should look for to determine if it's going to match well with the B&K amp???

Grannyring,
Yes life is very simple and enjoyable with SET amps.One output,driver and rectifier tube per monoblck, that`s it.
Regards,

You don't necessarily think that if the Emotiva was running to a tube preamp instead of Sony's SS it would help reduce the sharpness of the music?

Don't know. Depending on the particular tube preamp it might help somewhat, or it might turn out to just be more revealing of the shortcomings of the DAC.

In any event, if it is a matter of choosing which of the three components to upgrade, IMO it would make sense to upgrade the one that is the root cause of the problem, which appears to be the DAC.

If you are perceiving objectionable and similar sound quality with and without the preamp section of the Sony receiver in the signal path, it says that the preamp section is not the weak link in your system, and is not the primary contributor to the thinness and harshness you appear to be describing. If the tube preamp you were to choose were to largely resolve the problem, it would most likely mean that it is introducing colorations and inaccuracies that are complementary to those of the DAC.

In the near term, that would probably not produce as good a result as replacing the component that is the root cause of the problem. In the long term, if you were to eventually upgrade the DAC you would then be using it with a preamp that is complementing colorations and inaccuracies that are no longer there.

Finally, my impression is that good quality DAC's can be had these days at significantly lower prices than most good quality tube preamps.

IMO. Hope that helps. Regards,
-- Al

Thanks Al, that's good advice. Unfortunately the Emotiva is an "upgrade" that I just added a couple months back, and although it sounds better with the DAC than without, I was hoping the preamp could clean it up before the amp....but I believe you're right, in the end the source of the problem seems to lie in the emotiva DAC..

Anyone have any thoughts the previous question about what specs to look at when making sure the amp and preamp tube are compatible? (aside from the most obvious option - just listening) :)

Anyone have any thoughts the previous question about what specs to look at when making sure the amp and preamp tube are compatible?

The usual concern when using a tube preamp together with a solid state power amp is impedance compatibility. Ideally the input impedance of the power amp should be at least ten times greater than the output impedance of the preamp, at the frequency within the audible range for which the output impedance of the preamp is highest. That frequency will usually be 20 Hz, as a result of the impedance rise caused at low frequencies by the output coupling capacitor most tube preamps use.

A factor somewhat less than 10x may or may not be acceptable, depending mainly on how the preamp's output impedance varies as a function of frequency, and on the deep bass extension of the speakers.

I see that the amp's input impedance is 33K. The Little Dot preamp you are considering has a specified nominal output impedance (presumably at mid-range frequencies) of 600 ohms. The corresponding figure for the AES is 560 ohms. I couldn't find a number for the Dared.

It is possible that those figures will rise at deep bass frequencies to levels that would not meet the 10x goal, conceivably causing a slight rolloff of the deepest bass. I suspect that if that were to occur, it would be so slight as to not matter, but if you want to pursue those models see if the manufacturers can tell you what their output impedance is at 20 Hz.

Another factor to consider, especially given the high sensitivity of your speakers, is to avoid preamps having particularly high gain. Otherwise you may wind up having to use the volume control in the preamp too far down in its range, with the DAC's volume control at max (where it ideally should be). The Little Dot seems ok in that respect, its gain being adjustable to 3x (about 10 db). The AES's specified gain of 15 db may be getting into uncomfortable territory.

Regards,
-- Al