YouDontHasToCallMeJohnson
I have wondered about the in-guitar EQ and amp changing the impedance of the output.
TLW's response nailed it, nothing to add to that.
Over the last five years, what interfaces, in general, have you used/tested that you found acceptable?
Frankly, I haven't found any that are unacceptable. I do pay particular attention to crosstalk specs, though. I think that affects the "soundstage" considerably. But it seems no interface has everything - perfect drivers, superior response, low crosstalk, etc. Here's are some subjective thumbnail descriptions...
RME: Top of the line, if you have the bucks.
Lynx: See RME.
MOTU: Excellent drivers for the FireWire interfaces (haven't tested their USB stuff much).
Focusrite: You can't go wrong. Solid all-around interfaces.
Avid: The MBox line used to suck, so it's unfortunate that the excellent 3rd generation versions adopted the same name.
PreSonus: If you live in a PreSonus-based world, go all the way. I wouldn't say they're
ne plus ultra cork-sniffer audiophile gear, but they offer flexibility and low latency.
Roland: Solid specs, with useful features like auto-level and a pretty developed applet.
Mackie: The company never really seemed to get traction in the market but the hardware is solid.
TASCAM: I am currently using the US-4x4 because I love the class-A mic pres; they're neutral without being sterile. The 2x2 and 4x4 are basic interfaces, but that's because TASCAM put the "bill of materials" bucks into the mic pres.
All of these have direct inputs suitable for instruments with high-impedance outputs.