New memberUsername: Ktizzle
Post Number: 1
Platinum MemberUsername: Jan_b_vigne
Post Number: 17811
If the soundboard is "unpowered"; it does not include an on board power amp, then, yes, a soundboard would be a pre amp. More broadly, if there are no low level inputs included, both a soundboard and an audio pre amp serve the same function; they are used to control the flow of the signal as it heads toward the power amp. In this sense, pre amps and soundboards are best termed "control amps". Up to the point where low level sources were included in audio pre amps, this was a more common designation for what the pre amp functions offered the end user.
Low level and very low level sources would include magnetic phono cartridges and condenser microphones. Both of these sources require a "pre amplification" stage which steps up the low level output of the deice to a level which is more useable by the downstream power amp. In the earliest days of tape recording, signals were taken directly from the "tape head" which also required a boost in level before it could reasonably be passed on to the power amp. Very low level sources such as the typical moving coil phono cartridge will require a "pre-pre amp" device. In addition to that most phono inputs will include RIAA equalization of the signal.
Today, in consumer audio, a pre amp is assumed to be a device which includes both step up circuitry plus the eq for a phono input along with the line level inputs for digital sources. Pre amps which have no step up circuits for phono and, therefore, also lack phono eq would most appropriately be termed a "line level" pre amp. Here "pre amp" serves to imply the idea the component is essentially a "control amp" which directs and manages the flow of signals toward the power amp(s).
Where a very low level moving coil phono cartridge might have a peak output Voltage of 0.25 Volts and a typical line level source such as a tuner or analog tape deck might peak at 1.0 Volt, most digital sources are fully capable of a peak output of 2.0 Volts. Since most soundboards - mixers - will accommodate the low level input of a condenser microphone with the use of a pre amp stage along with the average high level inputs of digital sources these two are control type pre amps roughly comparable to the average high end audio's pre amp. Of course, the soundboard/mixer includes the ability to combine multiple inputs into one common output. No such provision is included in the consumer audio component where only one source is used at any one time. So similarities are largely found between pre amps and soundboards while each caters to its own market requirements.
If the soundboard were to have a built in power amp - powered board, it is then best compared to consumer audio's "integrated amplifier".