Mr.EQ for Bass?

[moosapotamus]

Runoffgroove Mr.EQ


Built this on the breadboard and I like it for bass. Especially with a fuzz in front of it. The peaks/dips all seem to be in the right places.

One minor issue is that, with all the eq peaks turned off, the circuit acts like a high pass filter, cutting out a good bit of the low end.

I was going to try increasing all of the coupling caps (all 47n plus the 15n input cap). But would that also reduce the "perceived" level of each of the three eq peaks?

IOW, is it feasible to make Mr.EQ allow a full range frequency response when all the peaks/dips are turned off, yet still give a clearly audible bump when any of the peaks are turned on?

Thanks
~ Charlie

[tubegeek]

I was going to try increasing all of the coupling caps (all 47n plus the 15n input cap). But would that also reduce the "perceived" level of each of the three eq peaks?

I'd guess that would work fine, without doing all the math (I don't even know HOW to do all the math for some of those filters.) Maybe easy enough to just parallel every 47n with another identical one on the breadboard and give a listen? While you're at it, parallel the 15n with another 47n, too.

If you don't have enough of those caps on hand to do all of them, do as many as you can and you'll definitely get a sense. I don't see any section where it looks to me like there is an INTENDED interaction with the coupling caps. Notice that the tightest ratio between cap values is over 20:1 (47n:2n2) which says to me that the intention was to keep the interactions to a minimum.

[Eddododo]

only one way to really find out :-p
Do let us know so I can borrow your figures haha


oh wait... I see what you are saying- youre not talking about the circuit interaction as much as 'how much is this peak compared to the the loudened lows'
well.. only one way...

[moosapotamus]

Yeah, I was thinking that if you raised the overall freq floor, so to speak, then the relative height of the peaks would be smaller and (maybe?) less audible.

Believe me, "try it and see" is my mantra. I spent a good chunk of last night breadboarding all the different 4049/4069 filter circuits I could find in an effort to make use of the extra inverters in a TSF/Llama/Lion build. Mr.EQ was actually my first choice (a combination I've wanted to try for some time), but I just wanted to see what else was out there. Turns out I liked Mr.EQ better than anything else I tried. But it was late and I needed sleep, so I stopped where I was and posted my last thought about the overall freq response.

Anyway, I had some 0.1u ceramics and put them in parallel with all the coupling caps. To my ear it was still cutting out some of the lows, but it also just sounded kinda muddy and lifeless. So I guess I'll leave it as is. After all, if I want a full range sound, I'll just bypass it.

Thanks
~ Charlie