Impedance Question?


OK so I know there's a lot of threads about matching impedance with pre/amp.  It would be really nice if someone could help out here! The whole impedance thing confuses me (doesn't take much).

So if I have an amp that has 10k impedance what range for output impedance would work for a preamp?

Any help would be great!
sqitis

Why would they not use a higher value capacitor if that improves the sound and provides more pairing options? Cost can't be the reason since the price differences is not much. There must be other reasons or design tradeoffs.

Why would they not use a higher value capacitor if that improves the sound and provides more pairing options? Cost can't be the reason since the price differences is not much. There must be other reasons or design tradeoffs.
You are correct. The bigger the cap, the more coloration it will impart, regardless of the dielectric. As a result, you want the smallest cap to do the job right, if low coloration is your goal. A 0.47uf cap sounds noticeably better than a 5.0uf cap; capacitors are wound on a machine so they have not only capacitive qualities but also inductance and resistive qualities as well. The dielectric (Teflon, paper, polypropylene, etc) affects the sound as does the length and diameter of the part.

This is the main reason that some tube preamps don't play nice with some solid state amps. The coupling cap is too small, and one big enough imparts more coloration than the manufacturer is willing to accept. So the manufacturer solves the problem by declaration (example: ARC limits their preamps to power amps with 30K or more input impedance). We solved it by direct-coupling; others use output transformers (which have a different set of issues).
I’m curious to know what these issues are with direct-coupling are since I may go this path with the SLP-98.

Great info here fellas! Keep it up!

Ben
Why would they not use a higher value capacitor if that improves the sound and provides more pairing options?


1: Cost, the larger uF the more expensive.
2: Size, the larger uF the more real-estate it takes up.
3: The sound deterioration the larger uF you go.

Cheers George