Are Pre-Amps necessary?

This thread goes to show you many paths to audio satisfaction. Passives, actives, no pre, resistor based, pots, transformer coupled; seems all have their adherents.

It makes sense no pre would be most transparent, resolving, the straight wire concept. But some prefer flavoring, and bit stripping can be concern.
At one time or another I've tried all the above volume controls, I could see how one would prefer one over another. At present and highly likely long term, I'm keeping my present transformer coupled active pre. Adds flavor I prefer and virtually no loss of transparency, resolution. Also gives me added input for vinyl setup.

It makes sense no pre would be most transparent, resolving, the straight wire concept.

Go back earlier in this thread to see what a straight wire isn't always the most neutral. The problem is that a passive volume control isn't a bit of wire. If it were, it would not have a resistance value.


Math and engineering principles are at play here- when you put a resistance in series with a source impedance which is expected to drive something to the best of its ability, its rarely a good thing. This can cause an audible and measurable loss of bass and impact. Put simply, its an example of a thing that is too simple to to its task properly.


This is not to say that you can't get it to work. To do that you have to be sure that your source has a direct coupled output and is capable of driving the load (the input of the amplifier) properly. And the interconnect cables will have to be kept short, and RCA only (balanced lines can't be executed with a passive volume control and observing the balanced line standard at the same time).

The problem is that a passive volume control isn't a bit of wire. If it were, it would not have a resistance value.

And to all, active preamps have volume controls as well, and most times not as good quality as the better passives pre's usually use. Also active pre's use many other distorting/colouring components in them.

At least passive pre's usually only have a quality pot, which is why they are the closest in sound to going direct (a straight piece of wire) when used correctly.

And balanced is not needed if you only use <3mts interconnect, and in many case better as the balance inputs and outputs on many pieces of equipment, are opamps to make them balanced, when their true circuit is not, so your better off using the single ended inputs on those, again a more direct path, instead of going through opamp etc for balanced

Cheers George 

While I’m very much in favor of the consumer friendly policy of sticking to standards, I’m not sure that many of the benefits of balanced couldn’t still be realized if they weren’t exactly so.

I think the best way to delete the pre is to go directly from the source and avoid the additional passive volume control. In such a case, I don’t see why adhering to the balanced standard would be problematic unto itself.

Where I do see an issue with balanced, as opposed to single ended is at the amp inputs. Until amplifier manufactures adopt 2 to 2.2 Volt for RCA and 4 to 4.4 Volt for balanced input sensitivities for full power output. Many digital sources directly coupled to amps will often have to attenuate too much into many balanced amplifier inputs, and as such perhaps consequently run into a bit stripping issue. As it now stands, it might be better to sacrifice some of the advantages of balanced and use the RCA inputs. Hopefully this will change.

I think it behooves amplifier manufactures to adopt more complimentary standards for input sensitivities.

@atmasphere  I only meant straight wire comment as a theoretical. I've long found my active pre's superior to passives and dac direct. Bass, impact, as you mentioned, much superior with the two actives I've owned.