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Why are preamps so important?


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A passive pre-amp is probably the most transparent (or should be)
item you can put into the system whilst retaining the above

An active pre-amp is often not transparent - and adds "flavour" to the system.


Sometimes true, and sometimes not. A passive, which is potentiometer connected to some cables, into an amplifier can, and often does represent a variable low pass filter to the signal, which is a long ways from being either "neutral" OR "transparent." Every setting of the control yields a new and different frequency response. A very simple active preamp can eliminate this effect all together.

If you need 40dB of gain from a source to your speaker, it doesn't matter if you get 10dB of that gain in a box called a "preamp" and 30dB in the "amp" or if you get 20dB of gain in each box. To suggest that one of those gains adds "color" and the other doesn't is a misunderstanding of the functions. Again, the name "preamp" seems to be confusing. The entire front end of a power amp is..........TA DA.....a "preamp" - a.k.a. A series of gain stages. If they were moved physically into the preamp box, would you now accuse those stages of addiing color?

If you don't need the additional control and or gain, don't use a preamp. But don't not use it for the bogus reason it is adding color, any more than every single other gain stage (including the outputs of your CD players and inputs of your power amps) "adds color."

For going on a decade I have been quite suspicous of gain in digital devices. Almost like it is an implied discussion that gain in any CD/DVD/DVD-A/ SACD analog output is more neutral than in any active preamp. I find many expmaples of digital devices with edgy highs and lackluster bass detail. With so much going on in those digital boxes it is hard to decide if the gain stage is the culprit

Good points.

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Agreed Mark - but the words "should" and "might" were important in my response. Note : I said nothing about colour or flavour from the amp - it could be as coloured or as close to "straight wire with gain" as you like. I also made no mention of the output stages on the source nor the imput stages on the amp for the very reasons you listed.

Finally - I was trying to avoid expressing any kind of preference here - as you probably know I run an active tube based pre-amp and separate SS phono stage. I wasn't touting what I own as the right route for all which probably came across as recommending the alternative.

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