I built myself a little powered stage monitor. The Idea was that it would be fed a line level output from a mixer. It consists of :
Input jack
Preamp (opamp chip)
47k log pot
100W MoSFET power section.
The bonus with all this is that it could double as a small guitar amp. However disaster! It does the secondary task well but the line input is too hot for the preamp.
Choises -
1/ Put in a second "line" jack with a 47K in series before the preamp.
2/ Move the 47K pot to before the preamp.
3/ Put a second "hot" jack after the preamp but before the 47K pot.
Thoughts?
Input jack
Preamp (opamp chip)
47k log pot
100W MoSFET power section.
The bonus with all this is that it could double as a small guitar amp. However disaster! It does the secondary task well but the line input is too hot for the preamp.
Choises -
1/ Put in a second "line" jack with a 47K in series before the preamp.
2/ Move the 47K pot to before the preamp.
3/ Put a second "hot" jack after the preamp but before the 47K pot.
Thoughts?
Obviously, low-level signals benefit from entering to the preamp unattenuated but high-level signals should be tamed.
Use a 'gain' potentiometer before the preamp and a 'volume' one before it, or add a switch to bypass the preamp, or add a 'padding' swich at the input with a resistor network designed so that signal is attenuated by 20dB (10:1) when it's activated.
Use a 'gain' potentiometer before the preamp and a 'volume' one before it, or add a switch to bypass the preamp, or add a 'padding' swich at the input with a resistor network designed so that signal is attenuated by 20dB (10:1) when it's activated.
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