2. amps-preamps
  3. 1060874640

What does a pre amp do

I have been trying to get an answer to this question, but so far have not been enlightened

In a modern system, the role of a pre amp is really questionable.

Historically, a pre amp would provide quite a number of real functions such as source selection, impedance matching, maintain volume consistency from different sources, volume adjustment, mute, balance, even tone control, high/low filters

Today, most people have a single CD source with XLR interconnection, which standardized impedance and signal level. Some CD and DAC (such as wadia) has digital volume control. In fact wadia does recommend people to connect directly to their amps

At least in thoery, the best preamp is no preamp. Even the preamp manufacturers agree as evident by the extent they go to separating power supply, minimize signal path. Then there is the passive preamp

So here is the question, is preamp a historical appendix that audiophiles are afraid to get rid of due to the fear of missing out on some unknown elements of music. Or is it really a percived need created by good marketing programs to exploit audiophiles

The obvious answer may be to try it out with and without preamp in the same system. The results I have heard so far are controversial, some claims much better transparency and clarity while others claim there is a lack of dynamics and less musical

I do not believe answers from "experts" who happens to be in a sales position. They always give a very affirmative answer and yet refuse to let you do an A/B comparision.

Most modern preamps are an empty box, and do we need to pay high prices for a piece of equipment with no known function
ag007
twl
3,251 posts
 
I believe that preamps have a very important function. They provide control functions, source and output switching, and pre-amplifying of any source items which may be lower than necessary for the needs of the amp input.

As for analog volume controls in preamps, most are not that great, and could be improved, but there are some really good ones. On the subject of digital volume controls, the general consensus is that they are no good, due to "throwing bits on the floor". There are many articles regarding the subject of digital volume controls, and I haven't seen many favorable comments about them.

I also wonder about just what is the definition of a "modern system"? Does that mean CD only? What about analog turntables, and maybe FM tuners? Are these not part of a "modern system"? And that doesn't even consider any HT functions.

There have been a number of threads posted here about the direct connection vs thru a preamp. Many answers depended upon the type of gear being used, and the number of sources that the user wants.

Some people prefer to use a preamp and some prefer to go direct. The results may be better either way, depending upon gear used and user preference. However, I think that it is quite erroneous to consider preamps "a piece of gear with no known function".
ohlala
1,235 posts
 
Everyone needs some sort of volume control. Just considering a CDP as the only source you have several options, depending on your system. I'm sure, though, that there are better outboard volume controls and preamps than what are included in probably all CDPs. If they are worth the extra is for whoever to decide. Using my softest CD, I skipped my preamp, and the sound was quite the mixed bag, so at least with my equipment, the (active) preamp has a beneficial function.

Check out the Ultimate Attenuators: http://www.tweakaudio.com/products.html
Maybe you will find those as interesting as I did.
rcprince
3,070 posts
 
Contrary to your first stated assumption, there are a great many of us who use a tuner, a record playing system, a tape deck, and a CD playing system that does not have balanced connections or a volume control, as well as other sources. For those of us misguided souls, a preamp is kinda handy for providing gain, volume control, RIAA equalization and source selection and to balance the stereo signal between channels, in case our hearing is better in one ear than the other or a room problem causes the imaging of our speakers to be off-center. So preamps are not merely empty boxes, do serve a function, and are not a perceived need created by marketing programs designed to deceive. If your only source is a CD player with balanced outputs and integral volume controls, and you are happy with the sound from it, then you don't need a preamp, and no one is putting a gun to your head to use one.

By the way, why don't you try out with and without a preamp in your own system and listen for yourself instead of relying on what others have said? If you tell me you can't because your CD player has no volume control, then I'd say you could definitely use a line stage, either active or passive, unless you are willing to put passive attenuators on your amp and adjust them with each disk (and possibly track) you play.
gunbei
2,327 posts
 
I have two passive preamps and one tube preamp. The passives seem to pass along very balanced music and well defined bass, while my tube unit bloated those lower frequencies. However, I greatly preferred the midrange of the tube preamp which was rounder, more dimensional and absolutely involving in a way the passives couldn't match. And for that reason even with the muddier bass, I listen with the tube preamp in place because I love what it adds.
ag007 OP
3 posts
 
Apologies for any misunderstanding, surely the traditional preamp functions are still used by some, with mulitple sources or need volume control

The question should have been phrased as, is preamp necessary in a system with single source and built in volume control

Unfortunately my cd player does not have a volume control and I do not have an outboard DAC either, so I cannot try this out myself

There are numerous equipment on the market that may eliminate the need for volume control in preamp, such as Wadia, Musical Fidelity pre CD, outboard DACs with volume

So the question is in such scenario, what is the supposed value of a preamp
More to discover