Who is using passive preamps and why?

Paul is correct. Those who dismiss them as wimpy and lacking dynamics and bass simply don't know what they are talking about. That may have been their experience with them but that isn't the fault of the passive, it is the fault of the people trying them with other components they weren't well suited for and not knowing enough about the principles involved to solve the problem. Hook up a high impedance source to a low impedance passive into a low impedance amp and you get wimpy. Do it right and you get world class sound.

Here is the ugly truth about about preamps...the volume control inside all of them, active or passive, is a passive device. It is either an inductive voltage divider like a TVC or a resistive voltage divider like a potentiometer or stepped attenuator, but they are all passive. An active preamp adds a buffer stage so it mates well with a wider variety of equipment than the voltage divider by itself. If you choose wisely as Paul states, paying close attention to the source that's driving it and the amp after it then you don't need that buffer and you get glorious results with world class dynamics and bass. In fact, it is better than an active because you've taken out an unneeded gain stage.

Active preamps are for those who can't figure out what it takes to integrate a passive into their system, their source can't drive the amp loud enough so they need more gain, or they simply are trying to use a passive with components they will never work well with. Yes, you limit your choices for other components but there are plenty out there that mate beautifully with a passive.

Like I said earlier nothing has been said here that hasn't been said before.

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Active preamps are for those who can't figure out what it takes to integrate a passive into their system,...

While this statement does apply to some, I do think there are those out there that just prefer the sound/coloration of tube preamps or other active preamps for that matter. No harm, no foul. Right now I'm playing with a Berning Mico ZOTL as a preamp and do enjoy the sounds of the various 6SN7 tubes I'm rolling with it. I also enjoyed my time with a Jeff Rowland Capri. Overall, I still prefer both my passives, but I can see why some might just prefer an active circuit.

Some passives include an active buffer stage to solve potential mismatch issues. The SMc VRE-1 and Pass B1 come to mind. Both are fine preamps and an alternative for those whose systems might not be passive friendly.

Herman, I think there are plenty of people that know perfectly well how to match a passive between their source, cabling and amp, and even when getting all that right still prefer an active preamp. Obviously in the wrong system a passive preamp will stink, but we are not talking about something so gross as that. One has to wonder what it was about Albert's system that he preferred the DarTzeel to his Placette? On some level it seems to make sense, how could all that sophisticated electronics (and complexity)used to amplify the signal only to have to attentuate it yet again possibly be as pure as leaving the signal alone? Well, it seems that for some people an active will do just that, and not just with an $18,000 preamp. I still agree that with a good source voltage with low output impedance feeding a passive into a sensitive amp with high imput impedance it is pretty hard to beat a passive for SOTA sounds at a very affordable price. It is for many a very good option, but it doesn't mean others don't prefer actives to passives even under the best of circumstances. (I've had Placette, K&K, and Bent with Autoformers - all sounding wonderful, but I prefer my Joule and Atma-sphere preamps in my system). One must also consider that many may love sources and amps (and possible cables) that just won't well with a passive at all.

Herman, well put. I think another factor that hasn't been mentioned is the that highly efficient speakers could play an important role in getting sufficient gain from a system where a passive preamp is used.

I completely agree that some components demand that you use an active preamp and such systems are capable of superb performance, but I think perhaps you missed my main point. The main point of my post was that it is not the passive volume control causing the problem some experience, it is trying to use it with the wrong components.

Let me try again. ALL systems consists of some source of an electrical signal, usually a DAC chip or a phono cartridge these days, followed by a series of active devices that eventually amplify the voltage to a level sufficient to drive the speaker. At some point in this chain of amplifiers you must include a passive volume control. To keep it simple let's concentrate on a system that only plays CDs.

The most common way to do this in a high end system is to have some amplification inside the source which amplifies the DAC chip output up to around 2V. That feeds an active preamp which may or may not amplify the voltage but contains at least a passive volume control and a buffer. That is followed by an amp that further amplifies the voltage and can supply enough current to drive the speaker. There is nothing magical about putting the volume control where it is. It could be in the CD player, it could be at the input to the amp, or if the output of the CD player is robust enough and the amp input is benign enough so the buffer isn't needed it could be put in a separate box between the CD player and the amp which we call a passive. My point is if you blame wimpy sound on a passive it means you don't understand what I stated above.

How about this? I don't have a preamp of any kind. I'm using Pure Vinyl software which controls the volume in the digital domain using 64 bit math. I modified the source so the DAC chips are connected directly to the input triode tubes of my amp through a 1:1 transformer followed by 2 more triodes. In case you are interested they also just release a version called Pure Music which doesn't include the vinyl functions.

Check it out http://www.channld.com/pure-music1.html

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