2. amps-preamps
  3. 1171928888

Preamp output voltage...affect on volume???

I am in the middle of auditioning a new preamp which outputs 50 vrms max. My current preamp outputs 20vrms max. Assuming they are both pretty close in terms of gain and have the same number of volume steps (100 @ 0.5db each), does that mean the preamp with the 50vrms output will cause my sysem to sound louder than the 20vrms preamp (all else constant)? If so, how much louder?

thank you...
tboooe

Showing 1 response by shadorne

shadorne's avatar
shadorne
7,491 posts
 
Quite simply a higher gain will result in a louder sound. The volume dial alows you to adjust the gain. A higher maximum ouput implies nothing unless you know the maximum input level.

Suppose that all signals are RCA line level and unbalanced; input is designed for a max of roughly 2 Vrms and therefore the gain at maximum output appears to be at least 25.

Suppose that all signals are line level and balanced; input is designed for a max of roughly 4 Vrms and therefore the gain at maximum output appears to be at least 12.

These high gains are unusual for a hi-fi pre-amp as most pre-amps are close to unity gain at maximum levels...the advantage will be better immunity to RF/EM noise (likely a lower noise floor downstage of the preamp).

To get back to normal volume levels you need to;

1) reduce the power amplifier gain stages to compensate for a large signal at the input of the power amplifier
2) attenuate the signal so that it matches the input capabilities of the power amplifier.
3) get a power amplifier that is specifically designed to accept this higher range of input signals

Good power amplifiers will often have potentiometers to provide flexibilty to handle various input level ranges.
More to discover