Best preamp is no preamp: always true?

I think there is only one theory: The moment signal left the source it is already degrading.
The active preamp helps restore some of the lost signals while the passive just let it flow through.

S23chang I think in theory and practice to our ears that could be very true. Also the fact that the meitner comment provides good proof to practice, as I would agree that should be as good as a seperate pre if not better in some case's

Thanks a lot guys, I am surprised to see that there seems to be a consensus around active PREs that easily...so, when people talk about passive PREs and how it maintain the integrity of the original signal "no more, no less", could it be that it is in fact "less" (degradation of signal)and also a little bit of audio snobbery to KISS when in reality the signal needs to be restored by some active mechanisms?

newerphile,
It's just not a universally correct conclusion that passives are better.

I think one of the flaws in the "passives are universally better" school is that cables are regarded as having unity gain independent of frequency. In fact, cables (and their interactions with components) contribute to a network which can have an audible frequency dependence. One of the most important jobs of a preamp is to match the output impedance of the source plus its cable's capacitance to the input cable and input impedance of the power amplifer.

A confounding factor for resistive passives is that the effect they can have on frequency response depends on their setting. In some circumstances, higher volume settings will attenuate the highs more. If the power amp gets harsh at loud volumes this can be a "good" thing.

At an earlier stage in my system evolution I had a Tom Evans Microgroove phono amp driving a tube power amp through a resistive bridge passive attenuator and it worked fine--probably because the Microgroove had very low output impedance (hard to get the specs). However, my present tubed phonoamp absolutely requires a preamp (CJ Premiere 16 2)for uniform frequency response.

Then there is the question of overall system gain required to achieve the sound levels required. Most modern digital players are capable of producing output voltages that will saturate the power amplifer. Thus, their outputs need to be attenuated and extraneous amplification is just adding noise...or perhaps masking an undesireable artifact from the source. Still, an active preamp may be required to achieve the proper impedance matching.

In the case of vinyl-based sources with low output cartridges there may be a requirement for additional gain to be made up by the preamp as is the case in my present configuration.

It can take a pretty good (read expensive) active preamp, and a highly resolving system, to start hearing the impacts referred to above. If a system is put together appropriately a passive will do just fine.

The choice for passive versus active preamps is highly system dependent and there is no universal "always true" answer.

Thanks. So now the ultimate question: it seems that there is a strong measurable factors rationale behind the use of the appropriate active PRE, namely impedance, gain, etc. Does this mean that it is safe to shop based on measurements that "match" the rest of my system to short-list a few PREs or is it a case of meaningless measurements and the "perfect" match is purely based on listening?
Thanks, this is a great source of info for a newbie like me.