Hi, I found this opensource stereo input buffer circuit that I would like to try.
In theory this circuit could handle two high impedance mono inputs and provide a proper impedance line level output.
I had a look at the low pass RC filter (at the right end of the circuit) and calculated the frequency cut and I get approx. 159Khz which is way too high, especially for guitar hi-z buffers I think.
So I plan to replace the 1nF capacitor by a 6.8nF one (probably ceramic is enough for that low pass filter even though original impl use an MKT expensive cap), now I get 1/(2PI.RC) = approx. 23Khz with 6.8nF
I like the opamp design and also the use of a low power and fairly transparent TLC2262 opamp there (buffer will be battery power supplied), but would be interested to learn about other jfet alternatives (like the JRC chips we see in many designs)
Thoughts?
In theory this circuit could handle two high impedance mono inputs and provide a proper impedance line level output.
I had a look at the low pass RC filter (at the right end of the circuit) and calculated the frequency cut and I get approx. 159Khz which is way too high, especially for guitar hi-z buffers I think.
So I plan to replace the 1nF capacitor by a 6.8nF one (probably ceramic is enough for that low pass filter even though original impl use an MKT expensive cap), now I get 1/(2PI.RC) = approx. 23Khz with 6.8nF
I like the opamp design and also the use of a low power and fairly transparent TLC2262 opamp there (buffer will be battery power supplied), but would be interested to learn about other jfet alternatives (like the JRC chips we see in many designs)
Thoughts?
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