Hi guy's,
I'm looking for a schematic that has a variable input impedance, from 1M to 600Ohm.
Is there something like this?
Best Bill.
I'm looking for a schematic that has a variable input impedance, from 1M to 600Ohm.
Is there something like this?
Best Bill.
Get a 1Mohm pot, put a 620ohm resistor in series with it and wire it as a variable resistor in parallel with the input terminals of a JFET (or CMOS) input opamp in non-inverting mode.
Thanks for the answers guy's.
I tried this on my F51 amp and Engl 350, it makes a huge difference.
Question: Why isn't this a standard feature on every instrument amplifier?
I tried this on my F51 amp and Engl 350, it makes a huge difference.
Question: Why isn't this a standard feature on every instrument amplifier?
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I would presume a big difference in the sound too as the ability for an electric guitar to cut through the mud depends on the treble response. The pick-up of a guitar is quite similar to the situation with a cartridge in a record player - how you load it will influence the Q of the coil-cable-preamp. You might equally think about the impact of the input capacitance of the preamp and the capacitance of the hook up cable.