DIY Design and Build Overvoltage Input Amplifier Protection. HElp!!!

[thomgun_lc]

I think to build some circuit to protect my input bass amplifier from overvoltage. Usually if we use onboard preamp/ overdrive effect, the output voltage from our bass/guitar output can damaged our amp. Eventhough there are an input protection circuit inside our amplifier, but i think, it is better to build a simple external device, which can protect from Loud "POP" sound and overvoltage, and we can change range of this protector circuit, so this devices not cut the sound without our permission/setup.
Does anyone have an idea???
Absolutely, we need to build the pure one, so this devices not change amplifier's sound charater.
I think it is better to sacrifice this devices if overvoltage occured than your MARSHAL JCM, SWR, FENDER, VOX and your another favorites amp.
Thanks

[gain-wire]

Hi there. It sounds highly unlikely that a signal from a Guitar or Bass can overload any preamp, designed to amplify bass or guitar signals. Unless you mean the noise caused by hitting the jack tip on the ground plate or something like that. Or maybe there's alot of static in your environement...

In any case, you want to have a simpel circuit? How's this:
two 3volt zener diodes, back to back (in parallel, anode to cathode, cathode to anode) one junction going to ground the other junction going to your signal. This will effectively clip any voltage over 3 volts. Or any other voltage you choose. It should not affect the sound quality. You will not find a more efficient, simpler circuit. I found this in Forrest Mims' simple transistor circuit book. Actually the same circuit is used to prevent damage to many preamplifiers and other sensistive input circuitry.