affect of diode on sound

[bent]

can't find the answer....

does a diode is always affecting the sound....?

i want to use a diode on the sound line to prevent voltage or any unwanted thing to come back on the line, but i wander if just puting 1 diode will affect the sound ( like clipping diode).....

exemple:  (guitar in) - (diode) >| - (line out)

what do you think?

bent

[KerryF]

Thats just a diode in the way of the signal.  You can use diodes for compression and limiting.  Look at article on AMZs site.  It explains it well.

If you look at this month's FX-X contest, its exactly that, to put a diode in the way of the signal.  Look at my recently designed pedal called the Pusher Boost.  Its not finished in the design yet, but going...

When you put a diode to ground, it limits the signal (like in noise reduction units type of thing).  Limiting is also present in all diode clipping substances.

[GibsonGM]

Good idea, but a couple of things jump out at me, bent...a diode placed in series with the signal will 1/2 rectify your guitar signal, resulting in a very ugly, broken-up sound, as long as your guitar output is higher than the diode's Vf, or forward (turn-on) voltage.  If it's not, you won't hear anything, since a diode IS a 1-way valve with a threshold, as you obviously know.  Diodes are commonly used on POWER supply lines, to prevent improper polarity hookups or over voltages (Zener regulation).  Also to rectify, and occasionally this property is used in octave circuits.

I don't recommend doing a diode in the signal path as an actual project, but you could try it on a breadboard to see what the results are...sometimes doing a little experiment like that is fun, and it won't hurt anything.

If you want to "keep anything from coming back down the line", how about a capacitor to block DC flow, the real big concern most people have regarding signal lines?  Then you'd just pick a value that colors the guitar's sound the least (try .1uf to 10uf).  It will "rob" some of your signal voltage since it's a passive device, but it does the job (as input and output caps do in effect circuits).  Again, generally used with an opamp or transistor in a buffer or booster circuit, to make up for the signal loss ('insertion loss').

[Harry]

What Gibson said. I had a similar question a while ago. Basically if your guitar's output was DC voltage this would work like a charm unfortunately it's AC so a diode will block one side of the signal, half-wave rectifing it.

[petemoore]

but you could try it on a breadboard to see what the results are
  Or find a place in a circuit where the signal path travels through a wire [like to a 'sustain' pot], where splicing/making bypassable [like a wire wrapped around one end and touched or left open to the other end of the diode] would be easy.

[KerryF]

Also look at the Clipboard and Flexi Clip.  They use the diode in the signal path.  I built it and its pretty cool actually to experiment.  I did the Flexi Clip which is seperate diodes both ways all activated by DIP switches.  Germ diodes boost the tone nicely.  LEDs and Si diodes make a harsher, not so good sounding signal by themselves.  MOSfet and Germ diodes sound warm in the signal path.

[bent]

i did some test, and like GibsonGm said, the sound is totally ugly...

i'll try to find something else.....

oh well, thank's for all the answer....if i find , i'll post it ....

bent