Poll - Active vs. Passive preamp

Paul, doesn't your supratek use a passive resistor volume control? When you turn that knob to control the volume isn't that a variable resistor? Why is that killer and what you call a passive is not?

Amfibius, your problem with dynamics had nothing to do with the fact that the preamp was passive. If the volume is all the way up and it isn't loud enough you didn't have enough overall gain for your combination of source-speakers-room. Adding an active preamp with gain solved that problem.

Here is the bottom line. Most don't understand that ALL volume controls are passive. They may be in a box with active gain stages so we call it an active preamp, but the thing that controls the volume (resistor voltage divider, TVC) is ALWAYS passive. Designing it as a unit and using an active stage to buffer the input and/or output of the control removes variables for the uninformed audiophile and they often get better results with an active stage. Not because active is superior but because they didn’t properly implement the passive control. Most actives are plug_and_play because the standard is high input and low output impedance. This is easy to achieve with active buffer circuits in the preamp but adding an active stage must also degrade the performance in other ways. Passives can’t always follow these rules so what comes before and after is critical to their performance.

As stated above careful attention must be paid to impedances and cabling to maximize the performance of the passive. This is exactly what the designer of an active stage does for you, but if you are knowledgeable about what is going on and you don’t need the extra gain going passive is always superior.

Paul, that's not a "view," that's the way it works. You restated my point (albeit more succinctly) about buffering and all controls being passive so we evidently agree.

So why is a resistor volume control in your supratek "killer" and you dismiss them if they are in a separate box? The reason is that the designer optimized the drive and load on it. If you would do the same with a "passive" preamp you would get the same or better results.

Granted, most audiophiles don’t have the technical background or expertise to do this on their own and they therefore often get miserable results. It’s like trying to drive 85dB speakers with a 2 watt amplifier and declaring SET amps are no good. Like Amfibius they blame the passive preamp when it is actually the implementation.

Paul, I don't consider it an argument. I think you understand what is going on. What I would argue with are statements like "Passive for delicate purity, active for dynamic realism." This shows a lack of understanding about how the volume control is integrated into the system.

My system is not perfect but I can't imagine a system more dynamic. It's not because I do or don't use a passive, it is because what I do have is well implemented. I tried a passive with 10K Zin and it sucked the life out of my system because my phono stage has a relatively high Zout. Most active stages would sound much better because they have a much higher Zin, and many would conclude that active stages are better based on this very limited sample, but when I inserted a 100K passive it was magical.

A poorly designed active stage will not be dynamic just like a passive one won't work well if used in the wrong way. Since all volume controls are passive the whole discussion is kind of silly anyway.

Mural, I'm not sure how I corroborated it since my system uses a passive and is very dynamic. I discounted your statement because there are many systems with active stages that are delicately pure and many systems with passives that are very dynamic. I believe mine is both.