Line Level Effect Design

[aziltz]

I need to tweak an effect to use in a series Line Level Effects Loop.

I'm aware of the Adjusticator.  I could sandwich it around the effect, and have a switch for Line Level use or regular stompbox use.

Is that the easiest, or most practical way to achieve it?  I feel like taking the hot signal from a Tube Preamp, lowering it, effecting it, and then raising back up to Line Level again would add unnecessary noise. 


How much headroom would I need in a unity gain buffer to handle line level?  The Adjusticator itself is designed to give +20db and deliver line level at the output off of 9-18v.

[GibsonGM]

Why couldn't you just use a voltage divider on the effect output to lower the level to Line Level?  That's how a 'line out' is done on a guitar amp...just a suggestion....it could be put on a switch. 

[aziltz]

I suppose I could, I just thought an an active stage might be better for sound quality. 

I'm working with this for the Send/Return,
FX-RETURN:
0 dBV/ 47 kOhms
FX-SEND:
6 dBV/ 100 Ohms

The send is a Low Impedance Output, and the Adjusticator Input Stage presents a 100k input impedance.

[brett]

Hi

The send is a Low Impedance Output, and the Adjusticator Input Stage presents a 100k input impedance.

I'm not sure whether you are suggesting this is a mis-match and a bad thing.  Yes? No? 

You usually want the output impedance to be much lower than the input impedance of the next stage (about 10 x lower is good, 100 x lower is great as long as the input impedance of the next stage isn't into the megohms.)
cheers

[aziltz]

You usually want the output impedance to be much lower than the input impedance of the next stage (about 10 x lower is good, 100 x lower is great as long as the input impedance of the next stage isn't into the megohms.)
cheers

Right, I thought 100k was better than the typical 1M guitar input.

I want to keep this simple and small. It's only to be used in the effects loop but I want to make I'm not trying to dissapate too much power from the line level at the input and/or cause excess noise.  I think using the Adjusticator as my input and output sections will do just that.