Can a preamp improve sound quality?
What improves sound quality more pre amp or amp?
There is an awful lot of nonsense about this out there. A preamp is a high variable gain voltage amplifier.
A power amp has voltage and power gain, and is the more problematic.
Now it is easy and cheap to make a good voltage gain amplifier. Now forget the tube nonsense. A cheap 50 cent opamp chip is more linear and has better signal to noise than an exotic expensive tube. That is not debatable. So getting a clean voltage gain stage is relatively cheap and easy.
Now the next part is where it gets tricky. The tricky part is facility. That depends on what you want to use it for. Do you want digital decoding? Do you want full bass management? Do you want a lot of flexibility in the phono stage, to optimize LP playback? It is these kinds of issues that have a much bigger bearing on sound quality and enjoyment than the last nth part of an ultra low distortion spec.
Frankly I don't think a minimalist "straight wire with gain" preamp has much to offer in the current audio scene and especially the AV environment, if it ever did.
Speakers are now, except for the very high priced exotics, narrow front format and footprint, with much smaller drivers, than years gone by. That means that the drivers, will be bass limited if not in reach then in power handling because of excursion limits of the drivers. However still very few audio preamps have proper bass management which is ridiculous. The same goes for their ability to stream and or decode modern digital media. This issue is really important. It is nonsense that old analog media has better sound quality then modern digital media. It does not, and by a long shot.
This all comes down to the whole purpose of audio and AV in the home. In my view the whole point is to enjoy to the fullest possible extent the wonderful and unprecedented array of what is on offer around the globe whether over the Net or hard copy. I have been at this for over 60 years now, and I have to pinch myself everyday to make sure I'm not imagining all the fabulous high quality choices out there for the asking, and so easily obtained with the right equipment. So if you look at this way, a preamp with just a volume control and source selector costing thousands of dollars is a really dumb purchase. Yes, they are out there and rich fools buy them!
Phono is a different matter. Quite honestly, I think unless you have a legacy record collection or want to become a collector of vintage material, I personally can't see the point of getting involved with it. I know I will get a lot of disagreement here, but that is what I believe. Obviously because of my age, I have a large legacy collection of LPs. Now getting good LP playback is difficult and you really do have to know what you are doing. I'm certain people new to this do not get optimal playback. Setting up has to be obsessional. Even then there are a lot of ills LPs are prone to. So I use good vintage preamps for my turntables and then run them to my AV prepro. I am convinced equipment from the LP hey day is the beat approach. In my preamps I can change the front end from MM to MC by changing dedicated modules. I can optimize the loading of the cartridges in teems of sensitivity and capacitance. Above all they have ideal and controllable filtering for dealing with the HF distortion a lot of LPs are prone to.
It is these type of issues that allow preamps to improve sound quality, not the nth degree of a distortion measurement.
As far as power amps go then there is a difference I believe. I do believe that if you can afford a good powerful power amp it pays dividends. These days you have bewildering choice in options and topology of the design.
Lastly I think you have to ponder the wisdom of setting up an audio only system any more.
After all for most years of my life I have been confined by the limits of technology to have had audio only systems. I have to say the ability to marry audio and video seamlessly is an unmitigated pleasure. Now I know that there are many who say you should set up an AV system and an audio only system. To me this is just wrong advice. having video in no way detracts from audio performance, in fact the reverse is true. So you might as well put your hard earned dollars to work in a good AV system.
This makes sense. I have pointed out that most audio only devices, are not, and have not been for some time built for the prevailing conditions as they now exist. They lack the ability to optimize the performance of modern loudspeaker systems, and make it difficult for the user to enjoy to the fullest the wonderful and bewildering choices out there.
So starting to build a system in this day and age your electronics options are pretty much a receiver with pre outs that you can use with external amplification if you so choose, or a pre/pro with good and flexible decoding options (and often more) and good bass management.
This probably is not the answer you were looking for. However enjoyment of music and media in the home is not just about burnished knobs and front panels, and bragging rights about the last nth distortion spec with an exotic Russian tubes, but about easily capturing and optimizing playback from the myriad of options out there.
