Stompboxes @ Line Level

[mean_dorris]

Hey all,

I'm looking to put together a few effects to run through a mixing board effects loop.
So far, the flatliner compressor I've built in a stompbox has worked just fine.

I'm just curious as to whether or not there are input impedance issues I should be thinking about, given that the loop operates at line level. So far, google searches have turned up fruitless.

Any help on the matter or tutorial site linkage would be awesome 

Thanks!!!

[Mark Hammer]

There are 2 aspects of "line level".  One is the actual amplitude, and the other is the expected impedance.  For something like an Orange Squeezer, it might be useful to pick up a 10K:600R transformer.

[MartyMart]

Hi, you need to build a "re-amp" circuit ( google )
In general, Your pedal fx are expecting very low input from guitars and not line level at either unbalanced -10dB or balanced at +4dB
Re-amp circuit takes these signals and presents them to your fx at the required level/impedance,
Then you can use them to your hearts content on line level instruments or recorded tracks.

You may well also need the same thing in reverse after the fx, unless you are happy to come out of the fx into a guitar amp for example
and mic that up for a re-record.

So two things required,  level right down to fx ( re-amp box ) and level back up ( good Di circuit may possibly work such as Behringer Gi 100 )

MM.

[mean_dorris]

Thanks!!

I suppose I couldn't just achieve the same effect (taming the input signal) with a resistor, could I?

Are there any pcb layouts around for a re-amp circuit?

[MartyMart]

http://www.prodigy-pro.com/diy/index.php?topic=30825.0

Check this out, bit more to it than just padding down the signal :-)

Simple enough to wire "point to point" or on perf board.

A 10k-250ohm transformer is a good starting point.

MM

[merlinb]

I suppose I couldn't just achieve the same effect (taming the input signal) with a resistor, could I?

That depends on the sort of pedals you use. Some pedals (mainly the old fashioned ones) sound different when driven by a real pickup than when driven from any 'conventional' circuit source. If you use modern, buffered pedals then you can just attenuate the line level with resistors, no problem. If you have some antiquated mojo pedals then you may want to emulate a pickup by doing what the reamp does.