tiny tremoloOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

[artifus]

[Jasonmatthew911]

Awesome!...Problem solved!...Thanks a lot!

[deadastronaut]

cool nice one art...


@jason , so is it behaving ''choppy'' now?...after your distortion?

[Gurner]

Art's nicely drawn diagram is pretty much what we were saying to Jason in his original thread....

http://www.diystompboxes.com/smfforum/index.php?topic=102137.40

i.e. put a resistor in front of the LDR (or roll the guitar's vol pot down), but be aware that doing so will result in significant a loss of signal volume (which may or may not matter depending on what follows)

[deadastronaut]

ahh i see..

so would a buffer on the out recover it ok?

[Gurner]

so would a buffer on the out recover it ok?

an amplifier would....but then it's not really 'a tiny tremolo' & you'd have to be rename it to .....  "tremolo" (which isn't anywhere near as snazzy)

To keep it tiny & make it more choppy, you could have the 555 drive an N mosfet gate instead of an LED ....and place the mosfet where the LDR is in art's diagram above....and place something like a 1k resistor for that top left series resistor. Then you'd have almost no signal loss & it ought to work on low impedance signals as well as high impeance raw guitar signals. You could call it tiny killer :-)

[Jasonmatthew911]

cool nice one art...


@jason , so is it behaving ''choppy'' now?...after your distortion?

Yes...Works great after the distortion now, chops are intense...I like!....That's what was missing, to connect 1 LDR leg to input and the other LDR leg to the output with the 10K resistor to GND...You should update this to make the TT usable after other effects....Great simple circuit.

[Jdansti]

Good job, Art!

[Gurner]

...as I said a good while back in this very thread...

without some form of in line (series) resistance preceding it, it cant/wont work as a potential divider.

Think about it..... if your AC signal coming in is 500mv & the LDR is 1M , then 500mV is dropped across 1M, if the LDR then drops to 10k that same 500mV is still dropped across 10k - so, the signal voltage remains the same at the top of the LDR .....what changes with the LDR changing resistance is the current through the LDR to ground (& might account for why there is so much clicking going on for some?)

If you roll the volume pot off a little on the guitar then that provides the necessary in series resistance for the LDR/rheostat to work as a potential divider.

Good work Art though (as they say a picture is worth a thousand confusing words!)

[Jasonmatthew911]

...as I said a good while back in this very thread...

without some form of in line (series) resistance preceding it, it cant/wont work as a potential divider.

Think about it..... if your AC signal coming in is 500mv & the LDR is 1M , then 500mV is dropped across 1M, if the LDR then drops to 10k that same 500mV is still dropped across 10k - so, the signal voltage remains the same at the top of the LDR .....what changes with the LDR changing resistance is the current through the LDR to ground (& might account for why there is so much clicking going on for some?)

If you roll the volume pot off a little on the guitar then that provides the necessary in series resistance for the LDR/rheostat to work as a potential divider.

Good work Art though (as they say a picture is worth a thousand confusing words!)

Haha...True...I guess what you said before was a little too technical for me...I needed it illustrated, but thanks Gurner, Art, Rob, and Jdansti...

[deadastronaut]

@jason, if you post up the new revised schematic, i'll knock up a new layout ok.

cheers.

[Jasonmatthew911]

so would a buffer on the out recover it ok?

an amplifier would....but then it's not really 'a tiny tremolo' & you'd have to be rename it to .....  "tremolo" (which isn't anywhere near as snazzy)

To keep it tiny & make it more choppy, you could have the 555 drive an N mosfet gate instead of an LED ....and place the mosfet where the LDR is in art's diagram above....and place something like a 1k resistor for that top left series resistor. Then you'd have almost no signal loss & it ought to work on low impedance signals as well as high impeance raw guitar signals. You could call it tiny killer :-)

I'd like to try this...Would the IRF520 Motorola N-Channel MOSFET do the trick?.....Do you think you could whip up a quick drawing showing exactly where the legs of the transistor should connect?

[Gurner]

I'd like to try this...Would the IRF520 Motorola N-Channel MOSFET do the trick?.....Do you think you could whip up a quick drawing showing exactly where the legs of the transistor should connect?

I was initially thinking this...


(I couldn't be bothered knocking it up neatly like art - I'm a back of a ciggie packet kind guy at heart...and I don't even smoke which means every time I have an idea I have to go & buy a packet of 20 cigarettes!)

...but upon reflection it'll probably 'click' (due to bleed through of the 555 driving waveform & the intercapacitance of the gate/drain)....better going with photo fet like the H11F1

the idea behind it is that mosfet acts as a on/off switch (in sympathy with the 555 driving waveform)...when it's on (gate hi) it's essentially a closed switch and shorts the signal to ground (just like a kill switch), when it's off (gate low), the pseudo mosfet 'switch' is open allowing your guitar signal to pass onwards unfettered. The end result will be a very aggressive choppy signal (i.e. changing from 0% guitar signal -> 99.5% signal-> 0% guitar signal)...but like I say, unless you go with the photo fet, you're likely gonna get click-age!

[Jasonmatthew911]

I'd like to try this...Would the IRF520 Motorola N-Channel MOSFET do the trick?.....Do you think you could whip up a quick drawing showing exactly where the legs of the transistor should connect?

I was initially thinking this...


(I couldn't be bothered knocking it up neatly like art - I'm a back of a ciggie packet kind guy at heart...and I don't even smoke which means every time I have an idea I have to go & buy a packet of 20 cigarettes!)

...but upon reflection it'll probably 'click' (due to bleed through of the 555 driving waveform & the intercapacitance of the gate/drain)....better going with photo fet like the H11F1

the idea behind it is that mosfet acts as a on/off switch (in sympathy with the 555 driving waveform)...when it's on (gate hi) it's essentially a closed switch and shorts the signal to ground (just like a kill switch), when it's off (gate low), the pseudo mosfet 'switch' is open allowing your guitar signal to pass onwards unfettered. The end result will be a very aggressive choppy signal (i.e. changing from 0% guitar signal -> 99.5% signal-> 0% guitar signal)...but like I say, unless you go with the photo fet, you're likely gonna get click-age!

Ok, so if I try an H11F1 Photo FET, where would each leg go and would this result in less volume loss and more killswitch chop?...I'm assuming that legs 3 & 5 aren't connected, so I would use the Anode and Cathode legs the same way you connected the N Mosfet and then just use 1 of the Output Term. legs or both?...If it's not too much trouble, do you think you could do another quick drawing with the H11F1 connected?...Thanks again

[Gurner]

Ok, so if I try an H11F1 Photo FET, where would each leg go and would this result in less volume loss and more killswitch chop?...I'm assuming that legs 3 & 5 aren't connected, so I would use the Anode and Cathode legs the same way you connected the N Mosfet and then just use 1 of the Output Term. legs or both?...If it's not too much trouble, do you think you could do another quick drawing with the H11F1 connected?...Thanks again

here you go...



You might get away with less than 20k for that top resistor (the 'on' resistance of the HF11 is quoted as about 200hms, so that ought to yield approx 100:1 attenuation)...you'd need to experiment to suit your own ears/situation (ideally, you want it as low as you can get away with).

I don't ever dabble with the 555 (I'm an MCU kind of guy & use PICs to generate square waves when needed)...so the 330R series limiting resistor was just a stab in the dark ...but it'll should get you up & away.

[Jasonmatthew911]

Ok, so if I try an H11F1 Photo FET, where would each leg go and would this result in less volume loss and more killswitch chop?...I'm assuming that legs 3 & 5 aren't connected, so I would use the Anode and Cathode legs the same way you connected the N Mosfet and then just use 1 of the Output Term. legs or both?...If it's not too much trouble, do you think you could do another quick drawing with the H11F1 connected?...Thanks again

here you go...



You might get away with less than 20k for that top resistor (the 'on' resistance of the HF11 is quoted as about 200hms, so that ought to yield approx 100:1 attenuation)...you'd need to experiment to suit your own ears/situation (ideally, you want it as low as you can get away with).

I don't ever dabble with the 555 (I'm an MCU kind of guy & use PICs to generate square waves when needed)...so the 330R series limiting resistor was just a stab in the dark ...but it'll should get you up & away.

Thanks!...I'll order a couple H11F1's and experiment...I'll let you know how it goes.

[artifus]

just for the record - i didn't draw anything here, i just typed 'simple tremolo circuit' into google image search and those two popped up on the first page. if you right click and select 'open image in new tab' you will see where they are linked from.

[Jdansti]

Most of us have germanium diodes in our parts bins.  Has anyone tried using a germanium diode in reverse bias and coupled with a super bright LED as a chopper? See this:

https://www.dropbox.com/s/hf25oxkrypwn3ev/Photo%20Germanium%20Diode.pdf

I got this from thecomedians post about old semiconductor books:

http://www.diystompboxes.com/smfforum/index.php?topic=102342.msg905695;topicseen#new

[deadastronaut]

^ mad diode use..


nice links to those old books...cheers man.

[CarlosP]

with this overall can use this:



This do that the wave gives a saw/sine on the led. i did test it, and doesn't generate the littel pop in the amp...

I just wanted to bring that data c: