Sharkfin - drowning in sweep

[Cortexturizer]

I just finished the Sharkfin, it's a bit of an honor to tell you the truth, not just that I've done it on the first Madbean board ever, but it's the first fabricated board [I kid you not!] I've ever worked with and in addition to that, I got it as a prize from the competition [thank you guys for voting really].
It's insanely easy working with fabricated boards, I couldn't believe the speed I've completed this with, and considering that I don't have much time currently for building, the ease of doing it really felt good.

Brian was kind enough to sell me two CA3080s, since I couldn't get em anywhere, not even Banzai Music carries em, and it just so happens that it was the exact two pieces that he used to develop this project, so that makes it even a bigger honor.

Now, before I present the finished pedal [nothing fancy, just an overall white sensation haha] I'd like to tune it a bit to better suit my setup and my guitars.
I play either a Gibson SG or a Fender Tele Deluxe with custom made wide range pickups. Both guitars have a lot of output [not insanely though, they are just hot guitars] and I find the Filter control on the Sharkfin to have extremely limited range of usability for me. Seriously, there's one point on the dial where I can play, anything less results in a cocked wah sound that displays no envelopiness at all, and everything more than that [like, just a touch, and this happens from 11 o'clock and further on the dial] and it becomes unusable, it's drowning in sweep, I have to wait literally for 15 seconds for it to comes back from the, let's call it, the amplitude of the sweep, it's highest point or whatever...
This makes the Attack control unusable for me as well, cause I can hardly use the effect with Attack on zero, if I were to turn the attack on max, and the filter past the point I was telling you about, I could as well go have a cup of coffee and when I return I'd hear the sound coming back from the sweep

Now when I turn the volume down on my guitar, to let's say 7, the pedal responds much better. That lead me to believe that the input signal is just too hot. Strangely enough, I own a VOX 1904 wah, which made me fall in love with autowahs, and it exibits no problems whatsoever with whatever pickup I throw on it.

I haven't had the time to tinker with the schematics much, nor do I have any past experience building envelope filters, so any help would be appreciated. I guess there has to be a resistor I'd have to change, or use less gainy tranny on the input or something, some of you will know the best course of action.

I noticed that the sample and hold side works much cleaner and more musical when I turn my guitar volume down.

[midwayfair]

First, dial down the decay and see if that helps. If it doesn't, make sure you've used the right value for the hold cap (C6).

R15 is a limit into the envelope section. You can increase that -- I'd use a socket until you find a good value, but i suspect 68K will be sufficient (figuring 7 on the guitar = 50% signal, so I'm halving the signal allowed into the envelope by increasing R15 by ~50% of the filter pot's value).

Finally, R1 and R2 form a voltage divider at the input. You could replace R2 with a 100K pot and have an input gain control. Not as preferable due to messing with your output, too, but it would mimic the effect of turning down your guitar.

[Cortexturizer]

...and that locks this thread. Haha, thanks midwayfair, I'm gonna try that as soon as I get home, one of these has got to help!
Any other humbuckin' guys that noticed similar Sharkfin behavior?

[Cortexturizer]

I put a 100K resistor as R15 and it made the pedal so much nicer for humbuckers. Now the pedal has just perfect performance. The controls are now much more interactive cause the Filter knob is very responsive across the whole dial. Attack knob that I had to keep on minimum now can go even full tilt. Great.
I might try the suggested 68K value just to make it a little wilder but 100K does it for me. It's awesome. Thanks midway.

What I might do, is add a clean blend to the pedal, for the sample and hold mode. I found that it swallows the guitar tone a lot [which is awesome don't get me wrong] and it might be a bit nicer having some clean dialed in there for those ambient clean ballad lines and passages when Speed set halfway up or lower. I dunno, gotta try it first, if I like it it will end up in the pedal. Whatever happens, this pedal is awesome and I couldn't recommend Brian's boards enough. As someone who has etched his own boards in a very primitive techique, and has had a long history of vero, I have to say, DAMN, this is soooo much easier. Given that I don't have that much time to build any more, I think I'm gonna go fabed boards from now on. [except for vintage fuzzes, they are always nicer on vero and perf hehe]

[pryde]

I agree woth Cortex and am very spoiled by fabbed boards. I have built a lot of vero and worked with etched boards but will always use a fabbed board if available.

I have had similar issues with my sharkfin. I may have to pull it from the "for sale" bin and work with it a bit.

[Cortexturizer]

Pride just bump that R15 resistor to 100k and keep the pedal

[Droogie]

Interesting thread in that I'm having the opposite issue—old-school Tele pups aren't triggering the filter very well—more of a fixed wah thing. If I take the values discussed above in the opposite direction, lower R15 and raise R2, would it increase the sweep and raise the input gain? I guess it's also possible I have a different issue with my build.

And yes, Bean boards are great to work on!

[Cortexturizer]

Well, if you dont have any problems with the build I'd say try it and see if you like it.
I tried the clean blending idea and it works awesome, now I have to include it into the build, the sample and hold side then becomes a lovely companion to your clean signal whereas without the blend it's mostly an crazy and smashingly beatiful gimmick.

What about you Pryde, did you try changing R15 on your build?

[midwayfair]

Interesting thread in that I'm having the opposite issue—old-school Tele pups aren't triggering the filter very well—more of a fixed wah thing. If I take the values discussed above in the opposite direction, lower R15 and raise R2, would it increase the sweep and raise the input gain? I guess it's also possible I have a different issue with my build.

And yes, Bean boards are great to work on!

Just lower (or jumper) R15. Don't touch R2 if you don't have to. But do verify everything about the build before modifying -- this envelope should be able to open at max on almost any type of pickup. In particular, make sure you've used the right value for R17.

The bad news is that you have a lot less room to maneuver than Cortexturizer did. If even a jumper for R2 doesn't fix the problem, try using a 250K for the filter pot to retain more signal. (There's kind of an upper limit to what you can get out of it.)

I'm starting to think I need to plan for a switch on my build to accommodate multiple types of pickups ...

[Droogie]

So I took a look at my build, verified values, checked soldering with 20x magnifier. Couldn't find anything wrong. Hmmmm.

Did I mention that I had only tried the filter half of the circuit? Once I hooked up the switch to change to the S and H, bingo! Quacking away with lower output pups. I guess I took "rock before you box" too far (insert sheepish emoticon here).

Probably no need to compensate for lower output pups—my Tele has very traditional output Fralins. Now humbuckers on the other hand...

As always, thanks for the help!