Passive Pre-amp: Improves overall sound quality??

This topic has been discussed at length in the forums more times than I can count. You might want to take a look at what is already been said. At a high level, you will note that people have some passion around this topic. There are different types of passives. Resistor based, transformer based, autoformer based, and others perhaps. These tend to be zero gain designs, so that all they can do is attenuate the volume from the source. They do not amplifiy. Resistor designs burn the extra volume off as heat, whereas transformers work by decreasing voltage by increasing current. You need to do some work to ensure that your source has high enough voltage to match the input sensitivity of your amp. Otherwise, you may not be able to achieve the desired volume. Also, especially with resistor passives, you need to make sure you have a match in input and output impedences, and you will need to keep the length of your IC's short. Otherwise, you may experience aberations at certain frequencies. They do not require AC power. They tend to be reletively inexpensive compared to active preamps at a given level of performance.

Personally, I like the transformer based designs (also known as TVC's) but I am not so hot on the resistor based designs. Most of the passive advocates will tell you they like the transparency and low noise of passives. Advocates of actives will claim passives result in a weak sound with no body, and will gladly sacrifice noise and transparency to get that body.
I haven't seen Sam's latest love affair? What piece is he hot on this time?

I think Atmasphere presented a balanced (and correct) view. And thanks for sparing us the partial differential equations and first principles analysis of why passives are inherently at a disadvantage.

I have benefited from use of passives while building my system. Along the way I've used passive or passive mode pre's from Adcom, McCormack, Endler, and two from Promethius. I now use the superb Promethius Signature TVC which runs about $2800 new. This was an easy choice for me, because I use a single source and don't need phono. Before you jump out of your skins, I do love vinyl and may go vinyl at some point. My current fixation on digital is primarily driven by the enormous advantage on availability of music, and the fact that my ModWright Sony is so good.

I have been careful to assemble a system around using a passive for volume attenuation and I could care less about remote control. At this point, my system is pretty good. I'm willing to begin to consider using an active. I expect at some point to A/B the Coincident line stage (5-6K) against my Promethius. No remote, 2 balanced inputs, all the money goes toward capability that I will use. By all accounts, it is a terrific piece. I'll be happy to keep it if it beats out the Promethius, even by a narrow margin.

I've heard far more actives that I dislike than actives I like. I auditioned a 20K BAT preamp that was very good. I've heard some other less expensive BAT stuff I also thought was pretty good, but I'm just not sure any of it could displace my Promethius. Most of the rest I've heard left me with an authentic "no thanks" reaction. What some hear as "body," I hear as unnatural dynamics compared to live music--the absolute reference.

I respect Atmasphere's advocacy of properly executed actives. His position is based on math, yet he stipulates there is a pragmatic consideration also. What each person has to do in assembling a system is define their needs and priorities. For people who need a full function preamp, it probably makes sense to put a good bit of money into the preamp and build out.

I started out a Maggie guy on a limited budget, so utilizing a passive "on the cheap' made some sense.

Do you suppose that Sunnyjim is really a troll, recognizing that we haven't all gotten our fists bloodied over the passive vs active debate for at least a month?

Atmasphere, Anyone who spends $10,000 on an IC has a problem no pre-amp can cure. :)