That is how I understand it. And the power amp delivers the current to drive the signals through the speakers.
Itâs important I think to consider that the pre-amp is just one half of the pairing that makes the whole amplifier.
I wrote the following some years back with regard to Naim pre-amplifiers. Iâll post it here as itâs still pertinent.
So, why have a preamplifier at all? Surely, the best preamplifier is to have none at all?â While it is true that less can often be more, itâs also the case that in Verekerâs words, âless is sometimes just lessâ.
The preamplifier is one half of the preamp/power amp partnership, which makes up the whole of the âamplifierâ. It is separated from the power amplifier to ensure that the electromagnetic fields from the power amplifierâs transformer do not interfere with the sensitive low-level signals within the preamplifier. This way, the preamp provides an ideal quiet room environment, further isolating the low level signals from the effects of microphonics, and ensuring that power supplies are kept well away where they can provide benefit without doing harm.
The preamp has a whole set of complex and vital tasks to perform; the input circuitry must accept the entire output of the chosen source without overload; the frequency response and level of the input signals must be normalised; the preamplifer then conditions the signal to ensure that the power amplifier is driven within its optimum operating parameters. On the latter point, Naim have traditionally taken the route of âbandwidth limitingâ the signal, to ensure that ultrasonic signals do not upset or limit amplifier performance.
All Naimâs preamplifiers, from the first NAC12 of 1974 right up to the current flagship of the range, the NAC552, have been designed to have a frequency response flat to within +/- 1dB between the critical 20Hz -20kHz audio frequency range and to offer âperfect stability under all working conditionsâ.
When designing the first Naim preamp, Vereker saw switched filters, loudness and tone controls as unnecessary impediments to good sound. He felt that their inclusion could never improve the quality of the original signal and always resulted in a loss of information. Instead he looked to design something with excellent stability, high overload margins (over 7 volts!) and with outstanding handling of music transients. The phono circuit had a linear first stage with relatively low gain, followed by RIAA equalisation which was split into two parts, active and passive. This way, complete theoretical and practical stability was attained, with a much wider open loop bandwidth than usual. Exceptional overload capability was thus maintained right across the entire audio frequency range.
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A few years back a chap on Hifi Wigwam had a beautiful Wadia CDP with built in volume control, Plinius power amp and big speakers convinced in the knowledge that a pre-amp would âtake awayâ from the sound. Partly out of curiosity and partly out of being persuaded by other audiophools keen to invest his money he eventually tried various pre amps and all added to the sound with improved soundstage and resolution. I canât remember which actual pre he eventually purchased but i know it was rather expensive!
Recognising that manufacturers are continuing to develop Digital source components with built in pre-amp functionality with great success at the same time I note that Naim are not alone amongst the high-end manufacturers in manufacturing dedicated pre-amps Vitus and Chord amongst them.
Regards,
Lindsay
Quite, as Richard D states the Naim preamp is part of the overall amplifier, not a seperate adjunct. Whether the source is digital, analogue or what ever is irrelevant.
Richard
Is there any way I could send a message to you off line about another issue I would value your input on?
Peter
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