If you can find out what level of attenuation the cable provided before, that would be helpful. Also, I can't tell from your write-up if this is a balanced/XLR attenuator cable or an unbalanced and perhaps stereo unbalanced (eg, 1/8" mini TRS with attenuation on both channels).
Anyway, this website is pretty helpful:
http://www.uneeda-audio.com/pads/For balanced, you'd probably want to use the U configuration, or for unbalanced the L configuration. Use 1% metal film resistors and buy extras beyond what you'd need just for this cable. Then hand-match the resistors using your multimeter to measure the actual resistance for each resistor. Very important to get the two balanced sides of a balanced cable matched as closely as possible. Also good to match the resistance across left to right channels, but that isn't quite as important.
If you had all the resistors from the cable, you could use your multimeter to measure them, but at this point, just decide what level of attenuation you want and use the info from the uneeda website to decide on resistor values. Just remember the formula for getting resistor values uses gain as "k", but this is measured as a ratio.
The formula for gain/attenuation in db is gain = 20 * log (V1/V2), or gain = 20 * log (ratio)
So if you want 20db of attenuation, you've got 20db = 20 * log (k), so K=10 (or I guess really for attenuation, -20 = 20 * log (1/k), with k again = 10). Similarly, 40db attenuation = 20 log (1/k), so k=100.
Once you determine what level of attenuation you want, you can figure out k, and then use the info from uneeda to determine resistor values.
Topic: attenuator help (Read 4189 times)