[gsk3]

Was playing around with the tube amp simulator in foobar and the pre-amp setting reminded me that I don't know what the heck pre-amping is. I assume it's a smaller amp that bumps up the signal before going into a larger amp in a speaker setup. I've never heard anything about pre-amping a headphones, except that I remember from a long time ago that a headphone amp is basically a pre-amp with a few modifications? Am I totally off here?
The bigger question is: why pre-amp? I assume for the quality, not the volume (can't imagine a larger amp couldn't get the signal to where you want it.

Thanks,
Ari

 

[hciman77]

The term pre-amp has a number of different meanings depending on the context.

In the old days amplifiers mostly consisted of two parts - a pre-amplifier (or control amplifier) and a power amp. The pre-amp had all the inputs, volume and tone controls and output a signal to the power amp which then applied more power to the signal and output it to the speakers. The power amp applied a fixed amount of amplification and the pre-amp determined the size of the signal it received. My understanding was that the pre-amp here cut the signal down from the full 1 - 2 V rather than amped it up - but I may be wrong on this

To confuse things not all inputs are line level - turntable cartridges output a very small signal with a really naff frequency response - to get a listenable sound you have to apply a eq to the cartridge signal - the infamous RIAA curve - the old pre-amps would have a dedicated eq and step-up circuit for this. Many modern amps however do not cater for turntable inputs so you sometimes need another pre-amp for the phono input.

As for software pre-amps - the metaphor breaks down here.

 

[gsk3]

Thanks. Makes much more sense now.
Ari

Quote:

Originally Posted by hciman77 The term pre-amp has a number of different meanings depending on the context. In the old days amplifiers mostly consisted of two parts - a pre-amplifier (or control amplifier) and a power amp. The pre-amp had all the inputs, volume and tone controls and output a signal to the power amp which then applied more power to the signal and output it to the speakers. The power amp applied a fixed amount of amplification and the pre-amp determined the size of the signal it received. My understanding was that the pre-amp here cut the signal down from the full 1 - 2 V rather than amped it up - but I may be wrong on this To confuse things not all inputs are line level - turntable cartridges output a very small signal with a really naff frequency response - to get a listenable sound you have to apply a eq to the cartridge signal - the infamous RIAA curve - the old pre-amps would have a dedicated eq and step-up circuit for this. Many modern amps however do not cater for turntable inputs so you sometimes need another pre-amp for the phono input. As for software pre-amps - the metaphor breaks down here.

 

[john_jcb]

Quote:

Originally Posted by hciman77 The term pre-amp has a number of different meanings depending on the context. In the old days amplifiers mostly consisted of two parts - a pre-amplifier (or control amplifier) and a power amp. ...........................

This is still how it works

. Most often both units are housed in one enclosure and it is referred to as an integrated amp. Many higher end setups still keep the two separate.