Frequency Specific Delay?

[Matteran]

Is there such thing as a delay that has a knob that will allow you to only delay a certain frequency and above?

I play bass, and sometimes my sound can get really muddy when the delay delay's all the frequencies, it would be really nice to only delay the high mids and above.

Is this possible?

[Mark Hammer]

It is absolutely possible.  I've done it, it's easy, and it works as you predict.

I don't know what chorus you have, but we'll take the venerable Boss CE-2 as a prototypic case since it is one of the more commonly found ones and resembles a lot of others.

If you look atthe schematic, you will see that just before the FET that is used to cancel the effect, there is a .033uf cap, followed by a 1meg resistor to ground.  Though the resistor is also there as support circuitry for the FET, the DC-blocking cap and resistor form a simple highpass filter that rolls off bass at just under 5hz.  If the value of that cap is decreased to .001uf, the rolloff is shifted upwards to about 160hz, which should take out a lot of what is driving you nuts.  On the Small Clone, there is a similar cap, only it is 1uf.  Dropping that to .0047uf will get you approximately the same thing.

Feel free to experiment with other cap values.  Smaller values will take out more bass.  Since the rolloff produced is not very steep. some bass will still come through, albeit at a much lower level.  For that reason you may find that the value/rolloff I suggested is still not high enough for your tastes.

A second thing you can do is increase the value of the mixing resistor for the wet signal.  This will be the last resistor in the delay path, prior to where the wet and dry are combined.  Increasing the value of that resistance will decrease the wet level and make it subtler.  Because 5% resistors will not always nail the perfect 50/50 balance for optimal chorus purposes, what I like to do is replace the stock resistor with the next lowest value down (so, e.g., replace 27k with 24k or 47k with 43k) and tack a pot about 3-4 times the resistance value in series with that.  That lets you dial in a perfect 50/50 balance (since youcan go from less than equal resistance to more) and also dial back the wet signal.  Not everyone likes it but I can see how it might appeal to base players.

Both of these provides a nice touch, making the chorus more of an animation to the sound than an overbearing effect.  You wouldn't be the first person on the face of the earth to say "I like my chorus but I just wish it wasn't so in my face".

[ultramusicman]

Is there such thing as a delay that has a knob that will allow you to only delay a certain frequency and above?

Harrrummmph!  In the amount of time it took me to register, verify, and log in, Mark beat me to the punch!  It's a good thing that there are 2n+1 answers where n = the number of forum members!  :-)

If you don't want to modify the innards of a favorite stomp box or if you want a different roll-off curve than your stomp box can apply to your signal, then you can try this:

Split your bass signal.  Send one to a mixer and the other to a High Pass Filter that has the desired roll-off characteristics.  Send the HPF output to your delay and your delay's output to the mixer.  If you have a Nord Modular G2, then all of this can be done inside the synth, although the delay time might not be sufficiently long for your needs.  Using MOTM, Moog, or other suitable modules would be a whole lotta fun.

(What?  No avatars on this forum?)

Cheers,

[puretube]

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[Matteran]

odd that you interpreted it as a chorus pedal. I have a chorus pedal with a frequency pot. But I guess it applies to delay all the same.

[puretube]

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this circuit by Sean in this very recent thread:
http://diystompboxes.com/sboxforum/viewtopic.php?t=30797&highlight=b+blender
(or one of the schems i.t. linx...)
could be used as a basis, when augmented by any kind of hipass filter...