Preamps can color sound considerably. Surprising?
Had the pleasure of listening to 4 hi end preamplifiers this weekend. And each preamp sounded very nice. But they were different. Each preamplifier has different circuitry and within the frequency spectrum there was more vibrancy in some areas versus other areas. Amplifiers are the same way.
It takes a while to appreciate sound differences between preamplifiers. And then you got the issue of Breakin which further changes the color.
clearly designers are playing around with all the internal circuitry in a manner that hopefully will be appealing. Clearly, these units do not get out of the way when it comes to moving a signal through the box.
I think solid state is more susceptible to coloring versus tubes. Tubes color sound as well.
It's all about marketing different ways to color Music. This isn't necessarily bad but it's never really talked about this way.
@atmasphere, could you kindly also get into the differences between attenuation and amplification? It seems hard to get across that most dacs only need the former whereas adding a pre by definition adds distortion. (While this may run counter to commercial interests, a degree of intellectual purity seems desirable in this discussion…) |
Pretty much all capacitors inside a preamp Color the sound. Are capacitors the sole culprit in coloring the sound? Great capacitors, like Teflon, allow the dynamics to be where they should be. The peeks and the valleys are respected. Assuming you have a great amplifier to go along with us. You hear preamp manufacturers touting our device gets out of the way it doesn't interfere with the music. This could not be further from the truth. Call it is what it is. |
The problem we're all up against is that Redbook requires for more voltage than any power amplifier would ever need. So the signal has to be attenuated to do any good. That means that in the case of a passive the control value becomes critical. Lower values like 10K work better, but most sources won't support driving 10K- they are more comfortable driving higher impedances. This can result in a loss of bass and distortion on the part of the source if its having issues. Active preamps do indeed add distortion. However they tend to be less susceptible to interconnect interactions. There are four functions that any line stage should have: 1) volume control 2) input switching 3) supply any needed gain 4) control the interconnect cable to prevent interaction Of these the 4th is least understood in home audio but well understood in pro audio, which is why they can use inexpensive cables and still get neutral sound. If the active line stage is good at controlling the interconnect cable it stands a very good chance of being more neutral than a passive device and possibly also lower distortion, depending on the passive device to which its compared. So its a mixed bag, which is why this conversation persists. |
Such a keen point. Charles |
@charles1dad it has been some of covered in a few places…
In theory it starts to barf when the passive is doing more control. Remember that the passive pre is attenuating both voltage as well as impedance.
The pros and cons from my list:
So the worst situation is driving some highly seniors give horns, at low volume through an amp with high gain from a high impedance source. The volume is then cranked around anticlockwise, and the passive is attenuating the already high output impedance of the source to become tens of hundreds of kohms. If it is less sensitive speakers listen to at higher volume then the passive does not attenuate nearly as much. If we add in ICs with high capacitance or inductance then we get a filter. |
