wht does a preamp do?

As with any variable output CDP, analog or digital, close attention has to be paid with other gear. Both resistive analog attenuators (or pots) and digital volume controls don't sound best till 80%. By adding a preamp in the chain you have normalized the attenuation and matched impedance better.

Others might find that the added complexity of a gain stage (or more) detracts from the sound.

Often, simple solutions are complex to apply and vice versa.

1. provides a volume control

2. provides switching to feed multiple sources to your amps

3. if so equiped, can provide balance and frequency controls

4. acts as a buffer so sources that need it can properly drive your amps

If you don't need any of the above, adding the active stages and cables associated with a preamp to a system can only degrade the sound.

If you do need the above, especially #4, then a preamp will make your system sound better.

Those who claim all systems need one have limited experience with systems that benefited from having one.

Some do, some don't.

I tried running my Wadia 302 directly into my amplifier and was not happy with the sound at all...upfront, analytical,too bright and hard. I am now using a tube preamp and the results are wonderful...warm, full, detailed and like real music. The sound I get from the Wadia with this configuration is almost vinyl-like.

The components which perform the function of the preamplifier can easily be put inside an amplifier (or a source component, especially if the source component has a really big box to house it). When you think about it, back in the late B.C. era ("Before CD" - as opposed to the current "A.D" era (After Digitial) - tongue in cheek), moving coil cartridges' output levels were in the single digit millivolts, which is about 1/1000th of the output of a CD player (current low-output MC carts are about 1/10th of that). Most amplifiers also do not have a built-in RIAA equalizer (required for records). It takes several gain stages to get from a millivolt cartidge output to a speaker level output. Most amplifiers simply don't have that much gain built-in.

In the age of single source systems, the role of the preamplifier could be taken over by a beefier output stage of the source component. However, beefy power supplies with high-quality high-gain output stages would increase the price of the source component. In a multi-source system, it may make practical sense to have to pay for a high-gain stage once rather than having one attached to every source component.

In your case, from what I understand, the implementation of the digital volume control on the Wadia 861 will reduce the bit rate of the output. The best sound will always come with zero digital signal attenuation (volume set at the top level). Unfortunately, that means the relatively high output voltage (double what most CD players have) means that one is obliged to turn down the volume most of the time, reducing the quality of the signal. In your case, the preamp allows you to control the signal in the analog domain, which will make music with lots of low-level detail (closely-miked cello or piano solos, acoustic jazz trios, etc) sound immensely better when played at less than wall-shaking volumes.

When I first got my Audio Aero Capitole CD player I ran it through the pre on my receiver. I had a hard time getting past my own personal bass and treble adjustments that were on the receiver.

Then I tried feeding the Audio Aero to the amp (McIntosh 2102) and bypass the receiver. This sounded much better. Using the Audio Aero's tubed volumn control I was able to power two amps into two locations with that balanced and unbalanced outputs.

At the moment I am using two unlike amps in the same room to bi-amp and I am now running the signal through a McIntosh CR12 AV system which has 4 individual preamps that can feed from one source if I like and this allows me to somewhat correct for the mismatched amps. With the McIntosh it sounds really good.