Is the source or preamp flawed?

I tried this experiment (using a preamp in the chain, or going direct) using my McIntosh MC275 for the amplifier, and my Wadia 27 DAC as the source. Both of these units have fully balanced as well as single ended inputs/outputs respectively.

And I discovered something really interesting. With a single ended hookup configuration, using a *good preamp in the path yielded better sonics than a direct hookup. However, using a balanced hookup, and running the source direct into the amp, produced the best sonics of all (to my taste, of course ;~) I don't know enough EE to speculate why, however.

* I did the experiment using two very good preamps, just because they were available at the time. One ss, and one tube; both of them with either single ended, or fully balanced inputs/outputs.

George, I agree with your remark

Those that say active preamps extract more detail, ambience or music from the source than direct connection are talking pure voodoo.
Those that say they like the colouration distortions that certain preamps bring to their system are being honest to themselves.

but it doesn't throw any more light on the subject at hand ;~)

The fact is that the (NOT particularly vast) majority of respondents seems to feel that having a preamp in the chain yields better results. I experienced BOTH kinds of "better" results (see my previous post) depending on whether I used single-ended or a (fully) balanced hookup configuration.

I'm only an 'amateur' electrical engineer, so not informed (enough) to speculate on why I got the results I did. Usually with something like this, it's (largely but not completely) about impedance matching. But there are other factors, like the effect of the buffering circuits in most preamps.

I also want to say (before someone inevitably asks ;~) that my 'preferred' sounding configuration (with preamp) in S.E. mode did not sound the same as my 'preferred' sounding configuration (direct) in BAL mode!

Re my equipment: I used a Levinson 26s for my ss preamp and an Atma-Sphere MP-3 for the tube unit. They are my two favorite preamps that I could ever afford!

My (digital) source is a Wadia 27 DAC. It has a very sophisticated volume control and Wadia designed it to be a direct source into an amplifier. (My McIntosh amp has volume controls on the S.E. inputs only, so I left those wide open to keep apples to apples ;~)

The most interesting part (for me) of setting up these A-B experiments, was making sure that the (generally accepted) optimal 1 o'clock preamp volume setting could be used with BOTH preamps AND with more or less the same level setting on the Wadia DAC. Finding a practical volume control setting with one's equipment, and for most of one's listening, is another area (along with impedance matching) that I think can have a lot of influence on (subjective) listening results. One reason I wish more preamps had a choice of 'default' gain settings (like the Levinson does.)

So what did I like best? Well, I have to say that if digital was my only source, I'd run my DAC direct into my amp (in fully balanced mode.) But that with so many sources, along with subwoofer and headphone amp connection requirements, that just wouldn't be very practical for me, and not worth the very small incremental improvement (in dynamics) I noticed I got by going direct.
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