madbeanpedals::forum

Projects => General Questions => Mods => Topic started by: moosapotamus on April 01, 2014, 01:50:57 AM

Title: Stage Fright Mod Ideas
Post by: moosapotamus on April 01, 2014, 01:50:57 AM
http://www.madbeanpedals.com/projects/StageFright/StageFright.pdf

Still waiting on some parts, but had a few ideas to try on the Stage Fright...

1. A shape switch (ramp up/down) - a pair of anti-parallel diodes in the LFO a'la Tremulus Lune.

2. A vibrato switch - lift R40.

3. Phase filter mod - divert cap to ground in a pair of stages to switch them from all-pass to low-pass filters.

4. Fast/slow switch for speed caps in LFO.

Anyone else tried any of these, and/or have any thoughts on if they would be worthwhile?

Any other mod ideas for the Stage Fright?

I was not planning to try toying with the CV input this time around, but I am planning to do the univibe caps.

~ Charlie
Title: Re: Stage Fright Mod Ideas
Post by: ggarms on April 04, 2014, 03:04:24 AM
Charlie, I'm interested in trying the r40 lift. I have 2 built and populated stagefrights, one with the univibe set. I'll try it out and let you know how it sounds
Title: Re: Stage Fright Mod Ideas
Post by: Matt on April 04, 2014, 10:10:36 PM
Can't speak to the stage fright but I did the phase filter mod on a Ross phaser (also uses lm13600 ICs) and their was a noticeable volume drop.  FWIW
Title: Re: Stage Fright Mod Ideas
Post by: moosapotamus on April 06, 2014, 04:48:55 PM
Interested to hear how the vibrato mod works for you, ggarms.

I've done the phasefilter mod on an older small stone (CA3080, I think?). Don't recall any volume drop with that.

Still waiting for LM13700 and 2N5457, then I'll be good to go. 8)

~ Charlie
Title: Re: Stage Fright Mod Ideas
Post by: Matt on April 07, 2014, 01:49:14 AM
Quote from: moosapotamus on April 06, 2014, 04:48:55 PM
Interested to hear how the vibrato mod works for you, ggarms.

I've done the phasefilter mod on an older small stone (CA3080, I think?). Don't recall any volume drop with that.

Still waiting for LM13700 and 2N5457, then I'll be good to go. 8)

~ Charlie

I should have clarified, the mod I saw was by Mark Hammer.  He suggested lifting the clean signal (vibrato mod) in conjunction with the caps to ground.  I thought that was the one you were referring to.  If you keep the clean signal intact, it shouldnt change the volume or "perceived" volume.
Title: Re: Stage Fright Mod Ideas
Post by: moosapotamus on April 07, 2014, 08:21:02 PM
Gotcha 8)

~ Charlie
Title: Re: Stage Fright Mod Ideas
Post by: madbean on April 07, 2014, 10:21:42 PM
I have listened to it in 'vibrato' mode and it sounds good that way. Quite an accident: the first prototype omitted R40!

Fast/Slow switch sounds intriguing. May put two 22uF in parallel with C15/16 offset by a large resistor? If you did this on a switch to short the resistor, I think it might ramp down gradually, which would sound cool.
Title: Re: Stage Fright Mod Ideas
Post by: jvg13 on April 09, 2014, 08:47:31 PM
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Title: Re: Stage Fright Mod Ideas
Post by: moosapotamus on April 15, 2014, 01:10:28 AM
Cool ramp idea, Brian! I'd be psyched to give it a try, but not sure I understand exactly how to wire it up. Can you maybe explain me better? :-[

I'll probably have everything I need to get started on this some time next week, finally!

Thanks
~ Charlie
Title: Re: Stage Fright Mod Ideas
Post by: midwayfair on April 23, 2014, 12:49:28 PM
Well, here's one:

Q2 can just be an LED in place of the D-S connections (no gate connection). In fact, it makes the effect a lot more extreme if you use a super bright. I can't actually figure out why this is a FET, to be honest. It also sounds better with a J201 than a 2N5457. I'd also like to try a larger trimpot, and the trimpot can also work as a sort of combination depth/Q control, as it seems to change the tone a tiny bit when increasing the depth in a way that the Balls control doesn't.
Title: Re: Stage Fright Mod Ideas
Post by: MADWAGNER on May 06, 2014, 01:15:07 AM
I was actually going to try the vibrato mode mod today! Is there anything more to it than removing R40? Sorry for the noob question.
Title: Re: Stage Fright Mod Ideas
Post by: moosapotamus on June 05, 2014, 08:41:50 PM
Quote from: MADWAGNER on May 06, 2014, 01:15:07 AM
I was actually going to try the vibrato mode mod today! Is there anything more to it than removing R40? Sorry for the noob question.

Nope. That'll do it. 8)

~ Charlie