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
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
bin
119 posts
 
You have got to be kidding! Buy the best pre-amp you can afford or you are missing the boat. One of the most important pieces in the chain.
rgodin
85 posts
 
Just about every CD player, even expensive ones with a volume control use a cheap pot or digital attenuator and possibly a set of opamps. It's better to use the fixed output and control the volume with any number of good quality passive preamps or standalone attenuators.
redkiwi
1,092 posts
 
I have the Resolution Audio RC50 and RC 55, and the Audio Aero Capitole. Each has internal volume control that matches the quality of many high end preamps and supposedly also have very good output stages. I do not know why, but they do not sound right unless passed through a preamp. They all sound a little flat, lacking tonal colour and hard in the upper mid range on up - whether feeding my Plinius SA102 or my custom made valve monos. The improvement is not huge with a preamp, and you pay the price in transparency if it is not a darned expensive one too. In my case I use a high quality buffer stage between my CDP and amp. That way I get the result with no major downside (no pots or switches) for low cost. As I say, I don't know why, but maybe it is difficult to locate a good line stage within these smallish box CDPs. I have heard that the Wadia 850 and 860 (much bigger boxes) do not suffer this same problem.
ag007 OP
3 posts
 
Redkiwi, thanks for sharing your experiences. I have heard comments similar to yours regarding flat, lacking tonal color and a bit hard. There appears to be no reasonable explanation for this

I do not agree with Rgodin that even expensive CD players use a cheap pot or digital attenuator. Please read write ups on Wadia and Musical Fidelity site regarding their CD players with volume control

There appears to be some good observations on this subject with no shortage of opinionated or emotional people, but the real answer still seems to be elusive

For those who think I am against using a preamp, I DO have a Mark Levinson preamp in my system. It would be nice to find out what value this expensive box is adding

Please educate me with facts and data not rhetorics
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