consensus on passive preamps?

One of my DAC's has the option of running line level out to a preamp or through a stepped passive attenuator system. Since the DAC was built to produce 4 volts of output, lack of drive when going passive is not a problem. I've tried it both ways within the same system. Only difference that i could tell was that i had greater versatility in terms of being able to switch inputs and volume levels with the preamp in the system. This tells me that this preamp is doing exactly what it was designed to do: select the input and pass the signal as it receives it.

Other than that, my experience basically mirrors most of the other comments. Passive systems are harder to set up and typically lack bottom end warmth and overall dynamics. Not my cup of tea but that doesn't mean that others don't like it or prefer it over an active preamp. Knowing Tom's level of "tweaking experience", i'm sure that his system might change my mind about the whole subject. Sean
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I recently purchased a Placette passive to compare to my BC21 tube pre and a solid state. I paired the Placette with a Pass Aleph 3, as did Tom above, which does not have particularly high input impedance or sensitivity, and with Dunlavy SM1, which do have resonably high 91 sensitivity. If there was a loss of dynamics with the Placette, it must be subtle because I sure have not noticed it. In fact, while at a Modesky, Martin, Wood concert tonight (great new album by the way), I was thinking how much more striking and better sounding their material was on my system at home.

C.

So Flyfishnz, how does the Placette compare overall to the BC21?

Tim

I owned a Silver Rock Passive with the 0db gain. They also make one with 6db gain. It uses a completely silver wired transfomer / potentiometer. I've had other passives, and I agree with most of the comments here regarding the drawbacks of passives. But the Silver Rock has none of these issues. It is the most transparent pre-amp I've ever heard, and shows none of the weaknesses of passives. It is dead quiet, as it acts as an isolation transformer as well as a pre-amp. For more info, please read the TAS review of it where they compare it to a $15000. active, and also the TAS review of the Halcro amps where they used the Silver Rock with them. It is expensive for a passive and looks like hell, but it sounds great! I sold it because I went to a Tact (2.2X).

A bit off the subject, but I'm very surprised that Marakanetz didn't like the 2.0. I've set-up two 2.0s for friends (they don't have laptops), and the Tact is stunning. Both of these guys now agree with me that the Tact is a "must have" in any system. I also thought that the volume control was completely transparent when the Tact was used only for this purpose. We went back and forth with it in and out of the system using a passive and an active pre-amp. Perhaps you could comment further on what you didn't like about it?

Successful use of a passive preamp is system dependent. In a highly resolving system the passive should be more accurate to the source signal. The ideal "passive preamp" simply attenuates the source signal without capacitors or transistors (which change the sound). Therefore the signal retains more of its original flavor and sounds less processed and more pure. Loss of bass and dynamics is a due to a mismatch between output level and input impedence.

Ideally, the attenuator should be built into the source component circuit for the most accurate sound. This is because source signal does not have to travel through simply another component (less circuitry), and there is one less connection, and one less interconnect. It appears that some manufacturers realize this, like Audio Aero and Resolution Audio.