I built a passive attenuator to sit between my mixing desk and my PC. The output from the mixer was way too high for the PC, and this has solved the problem in a way. However, the sound is a little dull, and I'm lead to believe that may be something to do with "impedance mismatching". I can boost the treble after recording, but I'd prefer a better signal going in to begin with, as I suspect it will then sound even better.
I looked at the specs for the mixer, and all the outputs say they are "600ohm min load, min +4dBU, max 22dBU"
I looked at the specs for the recording interface, and the inputs say they are "min >20k impedance, -10dBV"
To make life easy, all inputs and outputs are unbalanced, so essentially I've contructed an "L-Pad" attenuator.
The attenuation itself obviously takes care of the whole +22dBu -> -10dBV issue, but I'm sure if I choose better pot I'll get a better result, whether that's in terms of quality of the pot, or a more suitable value.
At the moment I have a 100k log (audio) pot. across the "mixer output" (attenuator's input) between signal and ground. I then have the taper from the pot going to the signal line of the "recording interface input" (attenuator's output) - the ground of both is tied together.
As far as I understand, I've got two directions I can go:
1 - Just get a different value Pot... in which case, what value? 10k? 20k? 50k?
2 - Get a rotary switch, and then use a "series and shunt" resistor on each position... but again, what should the resistance add up to? 10k? 20k? 50k? 100k?
I'd really appreciate some advice, particularly with regard to how to work out what total resistance should be.
I looked at the specs for the mixer, and all the outputs say they are "600ohm min load, min +4dBU, max 22dBU"
I looked at the specs for the recording interface, and the inputs say they are "min >20k impedance, -10dBV"
To make life easy, all inputs and outputs are unbalanced, so essentially I've contructed an "L-Pad" attenuator.
The attenuation itself obviously takes care of the whole +22dBu -> -10dBV issue, but I'm sure if I choose better pot I'll get a better result, whether that's in terms of quality of the pot, or a more suitable value.
At the moment I have a 100k log (audio) pot. across the "mixer output" (attenuator's input) between signal and ground. I then have the taper from the pot going to the signal line of the "recording interface input" (attenuator's output) - the ground of both is tied together.
As far as I understand, I've got two directions I can go:
1 - Just get a different value Pot... in which case, what value? 10k? 20k? 50k?
2 - Get a rotary switch, and then use a "series and shunt" resistor on each position... but again, what should the resistance add up to? 10k? 20k? 50k? 100k?
I'd really appreciate some advice, particularly with regard to how to work out what total resistance should be.