passive preamp matching

Well its pretty simple and I reccomend it with no reserves!!

You do need to have the right numbers for it to work properly:

First:

1-Amplifier Input sensitivity (Volts)

2-DAC (or cd player) output voltage

The Dac output must be higher than the amps sensitivity, usually a DAC will have 2 volt output and the input sensitivity will be around 0.5 volts: Thats why it works so good!!

Second:

1- Amplifier input impedance (ohms)

2- DAC (or cd player) output impedance (ohm)

This is the tricky part: You need at least 10 times lower impedance on the DAC than the Passive preamp and another 10 times lower impedance on the passive than the input impedance of the amp:
Lets say your DAC has 50 ohm output impedance,
and your amp has 15k ohm (15,000 ohm) input impedance;
You will be OK with a 1k preamp (such as EVS), But a 10k preamp will probably sound funny!

My DAC has 50 ohm output and my Amps have 1 meg ohm input.
The best sound I got was the 1K, it could work with 10k or even 100k but the volume was very hard to control (very little movement would blast the speakers) I had to go down from 100k to 10k to 5k to 1.2k and eventually settled at 1k, let me tell you the difference between 1.2k and 1k is big!!! It was fun all the way!

There are 3 types of passive preamps:
1-Carbon Volume pot based (Alps, Luminous Audio, etc.)
2-Resistor loaded (several types) (Placette, Dact, Goldpoint, etc.)
3-Transformer Volume control or TVC (Promitheus, Bent, Django etc)

I personally like the Resistor based ones better (I tried most of them).

Hope this helps

Keroo1099,

Sorry, I'm not personally familiar with the equipment you mentioned. Jsadurni's post is a pretty complete discussion of the key issues. Perhaps someone else might be able to comment on the specific gear you're asking about.

Jsadurni, many thanks for your input. Will now send time figuring out volts/impedance of various components.

I have a Placette and love it.

http://www.placetteaudio.com/passive_line.htm

The owner will answer all your questions and they have a guide for passive users on the home page (placetteaudio.com)

Good luck. He has a satisfaction guarantee

ET

A very strong second to the Placette recommendation. Absolutely fantastic! Like finally opening a slightly dirty window to breath fresh air and see the view unobstructed. Hey, they should use me for ad copy, eh? My setup doesn't conform to the requirements suggested above. My amp input impedance is only 10K. The output of the Placette is 2K which is only five times lower, as opposed to the ten times suggested above. I don't know the output of my Muse Model 2 plus dac that is doing duty as the front end, and how that might come into play, but the system works perfectly with no quirkiness at all. Raising the volume is a bit strange as the high volumes that I'd normally associate with severe distortion, do not have any apparent. The volume goes up and down as smooth as silk. In my system it is very engaging, crystal clear, and exhibits no dynamic shortcomings, nor any compromises at the extremes. Bass response is outstanding, and much better than the Cary tube pre I had been using as a pinch-hitter in this system. In other words, it has no weaknesses in my system that I can tell. Oh, also, I'm using 2 meter IC's between Placette and the amp and 2 meters between source and Placette. Length of IC is supposedly another issue to be aware of. It's a wonderful way to go if it works in your system. I'd consult with Guy at Placette if you have specific concerns (or with whatever company you choose to go with).

Marco