2. amps-preamps
  3. 1167527738

Clipping and the pre amp...

Clipping,

So, as I understand it, clipping occurs when you drive a speaker at close to the amplifiers total output power. Where I lose comprehension on this thought, is when I modify the input to the amplifier. My preamp, an LS25 MKll, in addition to the volume control, has a variable gain switch. The switch is marked with Low, Medium, and High positions. The instructions are to run the preamp with the switch set on the lowest needed position for whatever source you're running at the time. Does it matter then, if I've got the volume turned up high on the preamp, with the gain set to low? Am I more likely to run into clipping as I'm asking the amps to push near their limits to amplify a smaller signal? Or, are the amps not working that hard, as they're not amplifying a big signal to a big volume?

The preamp remembers positioning for you from the last listening session, so it's a set it and forget it thing. I do find the sound more to my liking with the pre amp gain set lower, and the volume set higher.

Or, is this a mute question as it's all related to the speakers? In my case they'd be the Gallo Reference 3's...

Thanks,

Dave
rolloff

Showing 1 response by aball

aball
2,016 posts
 
The "amplifier stage" is your amp, preamp, and source put together. The more gain your preamp contributes, the less your amp does for the same volume level. So if you turn the gain up on your preamp, the amps won't clip till further up the volume level. It is additive.

The source gain works the same way but adds a twist. If you take CD for instance, you get 2V to start with (roughly) but then very often your preamp won't output that much for your chosen volume level! Many times, a preamp will only attenuate the signal at the volume control and the gain stage won't contribute to anything. Hence the reason passive preamps exist.

This is assuming the volume stage is at the input. When this is the case, you need to have your preamp's volume control work in its "sweet spot." For your preamp, the sweet spot is at the top of its potentiometer (when it's nearly out of the circuit). This is the typical sweet spot location whether you are in the digital or analog domain and is why your instructions say to use low gain and high volume to get the best performance.

Arthur
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