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

Impossible to say without knowing what speakers are being used. Depending mainly on how their impedance varies as a function of frequency, some speakers will not sound right with one type of amp or the other.

It is also impossible to say without knowing whether the B&K amp or the preamp section of the Sony a/v receiver you are using is a greater limitation on the sound quality you are presently achieving. Not being familiar with either model, I can't address that question. And the answer may depend on the impedance characteristics of the speakers, and how difficult they are to drive.

As a general philosophical matter, though, if the speakers can work well with a tube amp I agree with the comments by Michael and Charles, and my vote would be tube amp, ss preamp. If you research past threads on this question, however, you will find that opinion is divided, and there is no consensus.

Regards,
-- Al

The preamp built into the Emotiva gives the music a very thin, scratchy sound at higher volumes...Im not familiar with how to describe it in audiophile vernacular, but it sounds digital with no richness. So I was hoping throughing in a tube pre after the DAC will clear up that problem.

This thread and this thread may be of interest. Among other things, these threads refer to issues with the digital volume control in the Emotiva DAC. If you haven't already, it would be a good idea to try running the DAC through the Sony with the DAC's volume control turned all the way up, with the setting of the Sony's volume control reduced correspondingly.

Although the adverse effects of the digital volume control can be expected to worsen as its setting is lowered, the reason that you may be perceiving the problem to a greater degree as its setting is raised may simply be that our hearing mechanisms become more sensitive to high frequencies (relative to their sensitivity to mid frequencies) at higher volume levels.

Beyond that, I wouldn't try to mask the problem by changing the preamp or amp. The best recipe for success is usually to try to correct the root cause of a problem.

Regards,
-- Al

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

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