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
 
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
bryans
104 posts
 
I have an AA Capitole running directly into my amps. I don't feel I am missing anything. I'm getting a preamp to run my LP with so I will try the test of my AA Capitole with and without a preamp. My plan is to just hook up the preamp when I want to listen to LP but if there is a REAL improvement to running my CD through a preamp I will find out. This could be the case but it just doesn't seem like it would be. My ears will tell me.
rgodin
85 posts
 
Wadia's site clearly states that there a loss of resolution unless the digital volume control is run at maximum (no attenuation). The more the attenuation, the higher the loss of resolution. If your amp has average gain and your speakers are more than average in efficiency, you are going to have the volume much closer to the bottom of the settings than the top.

I wasn't able to find a discussion of Musical Fidelity's volume control on their site. Is there a link ?

If transparency is what you want, then test driving a Placette passive might be worth the effort. It's not overly expensive, but supremely transparent and your money back if you don't like it. www.placetteaudio.com
ag007 OP
3 posts
 
Rgodin, many thanks for the info on Placette. It is worth looking into

I read the info on Wadia website and the understanding I have is that there are switches at the back of the unit that can be set to match the input signal level of the amp. It also states the volume is manipulated in the digital domian which does not introduce any losses or distortions. In fact Wadia does so much DSP to shape the noise based on empirical data from listening tests, the volume adjustment is just another step within this DSP which is taking place already.

As for Musical Fidelity, my understanding is that they actually have a preamp section (from their preamp product) integrated into the pre CD. MF is known to do that and spares no expensive to achieve good results. The Trivista SACD is actually a CD and a SACD inside the same box. Unlike other SACDs which is usually weak in CD playback due to sharing of same circuits which are optimized for SACD. This is one of the main reasons I bought the MF Trivista

Back to the original question of pre amp, notwithstanding that this is a known controversial subject, we should continue to get different views from people who have experimented. This does not mean all of us have to come to the same conclusion, but all of us will be making more informed decisions in pursual of our hobby

Happy listening
redkiwi
1,092 posts
 
I should add, the problems I reported on above were more with the Res Audio than the Audio Aero and I still run my Audio Aero into my tube monos. But the Res Audio runs through an SCE HRS before my Plinius SA102 - and there is no doubt the SCE HRS is worth its cost, the cost of a PC and an extra interconnect.
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