Converting line level to inst level

[rnolan]

This has become a bit of topic of it's own so started this thread for it.
After chatting with my audiofile mate, (and MJMP please correct me if I'm wrong coz you'll know this stuff much much better than me  :thumb-up: ).
To change line level into inst level, you use a voltage divider where one resistor (1/4 w should be plenty, allegedly metal film are the go) in series and one resistor to ground, the values for the resistors are (I'm told) dependent on the impedance of the line out and inst in and also how much you want to attenuate (IIRC MJMP said in another post in/out impedance should not matter in this case) , e.g. (my take on it) if the line out is 600ohms and the inst in is more than 10kohms... no impedance issues..
So at the inst end of the cable, you wire the one resistor from the cables +ve to the jack +ve (tip), and the other resistor from the cables +ve to ground (sleeve/shield).
This then becomes a fixed voltage divider; which is what I have in the end of the 2 leads I used to use to take the headphone out of my Rockman XL100 into 2 Marshalls.

You could also use a pot (which is a variable voltage divider) of the right value, cable +ve to pot in, pot out to tip, pot ground to ground/sleeve, then you can adjust how much signal attenuation as desired.  I haven't looked it up yet but there should be stuff on the net (probably wiki) how to calculate the resistor or pot values required.

[GuitarBuilder]

Sounds very complicated.  Just use one of these and your troubles are over:

[rnolan]

I don't know, 4 resistors and a bit of solder  :dunno:   The ebtechs look good, IIRC though someone posted that they suck your tone a bit ??

[rnolan]

Here's how to do it if you wanted to try this method (http://en.wikipedia.org/wiki/Voltage_divider)
  Figure 1: Voltage divider   In electronics or EET, a voltage divider (also known as a potential divider) is a linear circuit that produces an output voltage (V_out) that is a fraction of its input voltage (V_in). Voltage

[El Chiguete]

Dude you should make a little box for that and sell it... hell I would buy it!