Increased volume over time?

[docz]

Is there a pedal/circuit that will increase gain/volume over time? I was thinking of getting an effect where the guitar sound starts clean, then fades into clipping over the course of a set interval.

Any ideas, input or help will be greatly appreciated.

DocZ

[nexekho]

Pretty much any swell/noise gate?

[docz]

Hm.. I want to be able to set the time, and I want it to go from clean to dirty, not fade in. Ideally the perceived volume should not change much in the transition.
I tried to experiment with my SG-1 but it didn't do the trick.

Any other ideas?

DocZ

[nexekho]

I guess you could make a noise gate with an effects loop that reverse attenuates it after distortion to keep the volume level equal?

Guitar->fade in->distortion->fade out

[docz]

That may work, I will look into that. Another idea I had was to use a variable gain amplifier, and a LDR with a LED fading in or something like that to control the gain, and some sort of compressor/expander on the other side of the gain circuit.

DocZ

[darron]

i'd like to see the LED idea > dist > compressor.



it's easy to fade an LED in after all, but you might need some decent size caps if you want it to be over a very long time. i don't think you'd even need active components to process/boost the signal.

use the LDR as a voltage divider. there are usually two main sort of the small LDRs, ones that can go very low resistance (much less than 1Kohm) and also not very high and ones that go very high resistance (4M+), but not very low.

If you have a high resistance one put it in series with the signal and have a resistor afterwards going to earth (47K as a guess). This is my prefered option.

If you have a low resistance one, put a resistor in series with the signal and have the LDR go to earth.


i'll watch and see how it goes (:

[docz]

Great input! I'll check this out, does anyone have a Spice Model for LDR/LED interaction?

DocZ

[Mark Hammer]

I was thinking of getting an effect where the guitar sound starts clean, then fades into clipping over the course of a set interval.

Any ideas, input or help will be greatly appreciated.

This is, in fact, EXACTLY what the Gretsch Controfuzz does ( http://www.generalguitargadgets.com/pdf/ggg_controfuzz.pdf ).  It splits the signal at input, feeding both a clean path and a high-gain clipping path.  Because the gain of that second path is so high, the signal continues to clip long after the original clean input has decayed.  Because the clean and distorted signals are fed to separate (non-inverting and inverting) inputs, and because the distortion signal is severely attenuated (by R6), the clean tends to null out a big part of the distorted signal...until it decays.  As the clean signal decays, the still-sustaining distorted signal fades in, such that the output starts out pretty clean and gets dirtier over time.  It's an interesting effect, actually, and a too-often overlooked circuit.  Note that the timing of the distortion fade-in can probably be adjusted by: a) tinkering with the gain of IC1a (making R1 a 100R resistor in series with a 1k pot will probably do the trick) and b) tinkering with the value of the distortion-side input resistor to IC1b (R7).

[darron]

i've never used spice. i do things the slow way lol

[docz]

I like that controfuzz idea, pretty interesting sound, but I would like to adjust the timing to be even further, preferably adjustable with a pot or something. The "delay" between clean and fuzz in this circuit is pretty minimal, but still a real cool sound!

DocZ

[jafo]

Maybe a volume pedal? It'd give you plenty of control.