Do preamps have a material affect on high level sources?


It would seem that a preamp is merely attenuating a DAC output. How can it alter the signal?
If it doesn't degrade the signal, would logic dictate that at best it has no affect.
Help me understand
vjpacor

Showing 4 responses by atmasphere

The balanced Backert Labs Rhumba would be a good example. Any preamp that supports the balanced standard would do the same thing. That is one reason balanced preamps can sound better- you don't hear the effects of the interconnect cable. 
So as you can see this talk about active preamps being able to control the cables capacitance, is a huge furphy, thought up by active preamp makers to aid in their product sales.
Almost any audiophile on this forum has heard interconnect cables make a difference. In fact that is why there is a +Billion$/year cable industry in the US. This fact is incontrovertible.

It is the the fact that cables sound different that is why a good line stage is helpful- it is the artifact of those cables (IOW, not just capacitance) that a good line stage can control or virtually eliminate. Cheesy line sections and passive controls cannot do this.


If one needs an example of what I'm talking about, just look at almost any recording made in the late 1950s during the golden age of stereo recordings. At that time, there wasn't an exotic interconnect cable industry in the US (that wasn't to happen until years later when Robert Fulton produced the first high end interconnect cables in the late 1970s). Yet somehow Mercury, RCA, EMI, Decca and others were able to send delicate microphone signals up to several hundred feet apparently without serious degradation.

So apparently the technology to do that was around in the 1950s. A tech that is also not available to passive controls. It was done with active circuitry, with real engineering talent behind the design.


So when I say a 'good' line stage, I'm referring to one that is properly designed to include minimizing interconnect cable artifact as one of its goals. They are out there- you just have to look.
A good preamp will have very low distortion at the levels needed to drive a power amp and wider bandwidth than the source.

The main things that a good preamp brings to the table is a better volume control than the ones found in most DACs (there isn't a good way to do volume control in the digital domain) plus the ability to drive the interconnect cable to the amplifier properly, so as to minimize the effects of that cable. I've yet to see a DAC that deals effectively with either of these issues.

We sell a lot of our line stages to digital-only people- they run the DAC volume all the way up so as to minimize the the damage done by that control and use the preamp volume instead. The preamp then can drive long cables where their DAC can't. In this way they report that the use of a good line stage is more transparent and more musical- more like real music.


Note my use of the word 'good' above; many line stages are not up to the fairly simple tasks I outlined above, and so do damage rather than help.