High pass on reverb?

Started by remipinel, August 24, 2015, 06:05:06 AM

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remipinel

 hey guys! first post here. I'm still pretty new at building stompoxes.
I've been thinking of building my first reverb pedal, and I was thinking of a concept of splitting the input signal into two, one going untouched into the output and another going through the reverb circuit after going through a sort of high pass filter. this is just one vague way I thought of doing it, but essentially I'm interested if it'd be possible to only reverberate the higher frequencies of the input, of some sort of eq of what to reverberate, all this without affecting the original sound, only the echo.
I know this is kinda weird for a first reverb pedal but eh I like new things.
thanks

induction

Quote from: remipinel on August 24, 2015, 06:05:06 AM
I know this is kinda weird for a first reverb pedal but eh I like new things.

That's not weird, it's SOP. In all the Belton/Accutronic brick reverb circuits I've seen, the signal is buffered and split into a dry path and a wet path, and then mixed back together with a diff amp just before the output. Different designs have different types and amounts of filtering of the wet signal, and you can obviously adjust them to your own taste.

anotherjim

I think it's standard practice to feed the reverb block with a simple RC high pass starting maybe about 300Hz to keep the mud out. That's simply done choosing the input coupling capacitor given the impedance of the reverb input. If there's still too much mud, then the coupling capacitor value into the wet/dry mix from the reverb block can be fixed to suit.
The feedback (re-gen/decay) path is also filtered to simulate the different absorption rates of different frequencies in the "reverberant space"  you're simulating. A simple low pass is sometimes used since it's usual for the high frequencies of a space to decay first, but it can be more creative to use a tone control such as the Big Muff one to choose between high or low pass.

Mark Hammer

One of the things people like about plate reverbs is that they often do precisely that: leave the lows out and yield reflections of only mids and highs.