Are passive preamps better?

The Placette "Active" approach of following passive switching and volume control functions with a unity gain buffer seems ideal to me. In practice most preamps are operated at less than unity gain overall although within the unit there may be many dB of gain. Most of it is discarded in the volume control. Most disc players, for example, have a nominal output of 2 volts rms, and 2 volts would drive most power amps into clipping.

When I built my home brew "passive preamp" several decades ago I also built what I called a "line driver" which was a unity gain buffer amp with high input impedance and low output impedance. This was necessary when I changed power amps from tube units with 250K input impedance (high even for a tube amp) to SS amps more like 20K. I was very aware of output impedance requirements from my work as an aerospace systems engineer where it was necessary to transmit both analog and digital signals through as much as 300 feet of 20-year-old wires. There was always a circuit dedicated to this "line driver" job.

Since I don't have the $7000 maybe somebody will start manufacturing them for a fraction of the cost. I copied your response, Eldartford. Last night I tried bypassing the preamp with my H/K HD7600ll which has a variable output option. This player is so old that probably no one knows it anymore. In the late 80's--early 90's it was considered as good as any player on the market, so it's not a terrible reference. I tried this years ago with another system and the result was so horrendous that I didn't consider it with this system until last night. It sounds good. I get the quieter background and improved clarity. It might sound more like my brother's and sister's surround systems with less dynamics (but what is dynamics?) Maybe the music is slightly "pinched". Not sure. The manual volume control feels like a good pot but it's not motorized. I set it at half volume and varied the volume with the remote, and this volume control is of inferrior quality, I assume. So I don't know what these settings are doing for it or to it. All I know for sure is that preamps are an annoying necessity. Lynne

It didn't work. Back to preamp.

Arnettpartners...Just curious...in what way did it "not work"?

Eldartford, I later got distortion components. I only played two cd's that night after setting it up, and I thought that it was an improvement over using the preamp. But the following day when I tried other cd's I got a harshness that had not been present. The system had been powered off for a few hours before set=up while I was setting up a new cabinet. So if it was because it was relatively cold at first audition or the cd's I used or my own focus on the improved silent background and clarity I don't know. I guess I should try it again. I wondered if the inferrior output control makes it a poor reference. I'm a little frustrated right now because I think I'm zeroing in on a really good system. But I don't have anywhere near 7k for experiementing. I read partially the review in Stereophile on the active Placette. The reviewer is bananas over it. I guess the Placette is on sale right now for 4k. I just discovered here that your email address is available. Lynne