Preamp - what's the purpose?


Intentionally dumb question...

I've heard various 5-15W tube amps in my room. EL84, 300B, etc. They all have input stages and the output stage. I send them a line-level signal from a DAC.

Sitting a few meters away from my loudspeakers, the first watt alone gives me roughly 80db of volume. I think these amps are biased to expect the line level signal directly. Why wouldn't the designer do that?

So what's the point of adding a pre-amp? Why do people do it?

thanks in advance

 

clustrocasual
Post removed 

@mlsstl

+1

It puts the magic and bloom into the sound. While direct DAC to amp components are getting better, except in rare instances a great preamp is requirement for really good compelling musical sound. Lots of folks have connected DACs directly to amps only later realizing got all the detail and dynamics of recordings but lost its soul. I am sure a few haven’t discovered this an don’t know what they are missing.

Coming to this "hobby" from receivers and being on the lower tier, I need a preamp to connect all the sources I use. Turntable, T.V. and CD/DVD player. There is also a USB in for smart phone or laptop if I want. For streaming, I use a Bluesound node.

@arnold_h 

Paul McGowan from PS Audio was always saying “the best preamp is no preamp” and I tend to agree with him.

I ran my DSD DAC directly to my BHK250 power amp.  It sounded kinda flat, and by no means as good as when I ran the DAC through my BHK preamp.  Since I have a turntable and a R2R, I certainly need a preamp, but I just had to try it.  

It is all about system matching.  BUT IMO, preamps do more that what has been already stated above.  A good preamp will add dynamics, loud to soft to loud contract, speed, soundstage dimension - front to back - side to side, tone, separation of vocals and instruments, flow of music, definition, details, clarity, float high frequencies, provide a more beautiful mid-range especially with female vocals, woodwinds, and strings, a more realistic sound, etc.

Happy Listening.