Blade VSC Frequencies

[Pavlos]

having a look at building the Blade VSC pre amp from the main section

http://tagboardeffects.blogspot.co.uk/2014/09/blade-vsc-preamp-modified.html

from what I can gather from the post it looks like it's a mid boost, but no indication of roughly what frequency it works at. Also, if I wanted to change the frequency, which (I'm assuming) caps would I need to change? just thinking that it may be possible to use a DPDT on/off/on switch to give three optional boost frequencies?

MAny thanks in advance

[induction]

Center frequency is about 625 Hz.



You can adjust the center by turning the 500k resistor in the feedback loop into a 1M pot, but this will adjust the filter width and the amplitude as well. Might sound ok though.

[Pavlos]

Thanks Induction, much appreciated how radically would the a 1M pot shift the frequency both up and down? would it stay within sensible musical ranges or would it be worth putting a smaller value resistor in series with the pot to limit the range to something useable?

Thanks In advance

[induction]

At 1M, the center frequency is about 250 Hz. As you decrease the resistance, the center frequency increases while the filter amplitude decreases. By the time you reach 50k, the center frequency is about 5 kHz, but the amplitude of the filter is small enough that you might not hear it anymore. At a resistance of zero, the filter disappears entirely.

Notice in the plot above, that the center frequency and the peak width interact in such a way that increasing resistance adds bass to the filter without reducing treble. If you want something that keeps the filter width intact and just shifts the center frequency, you're better off building a parametric eq.