2. tech-talk
  3. 1205930833

What is a preamp?

I came upon this question when considering whether to leap for a Theta GenVII Dac/pre or maybe get a Gen Va and a good tube preamp. Theta's lit says that the GenVIII comes in 2 versions, one with volume control and one without. Somehow, just having analog volume control makes it a preamp. Do I understand correctly that switching and volume control is all a preamp is? Nothing else is happening to the signal? Why are good preamps so expensive then? And why do they vary so much in design of the circuitry? It would seem to me that the simpler the better, and volume control attached to the dac couldn't possibly be bested by a separate box with more cables, but I bet there would be lots of debate if I posted a Gen VIII vs. Gen Va and a tube preamp thread (actually I think I'll do that). What am I missing here folks? Thanks in advance. -Dave
dbw1

Showing 1 response by aball

aball
2,016 posts
 
Don't forget the buffering effect of a preamp because a preamp is an amp. That is probably its main advantage other than volume control and switching.

In most cases, the preamp actually runs below unity gain, which means that depending on the design of the volume control, the preamp spends most of its time attenuating the output of your CD player or phono stage. But the amp stage is still present and acts as a buffer. This can give an advantage when it comes to dynamics. Everytime I tried bypassing my preamp and running direct to amp, dynamics suffered so much that any possible theoretical advantages were swamped out. I've been using a preamp ever since.

Arthur
More to discover