tiny tremoloOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

[Manny]

Here's a link to a soundclip of my working NE555 version.

http://178.79.134.49/files/17_11_2010 19_27.mp3

Excuse the phone recording (could't be bothered getting all the cables out for logic  ) and the bad playing.

I seem to get a smooth trem sound rather than the truncated one you got Rob.
Must be the LED/LDR combo I'm using.

The slight buzz is because this is on BB sat right in front of the amp.
 

[Manny]

For those who are interested, here is the modified schem for NE-555.

I can confirm that it does not get hot and as long as the signal ground is separate to the circuit ground there is no click.
The 1.1K resistors may need to be adjusted slightly for your chosen LEDs.

I've omitted the LDR/in-out section, it's exactly the same as Rob's previous schematics.

Also, I forgot to label the resistor at pin 8, it's a 470r as in the original.

[MetalUpYerEye]

You're missing the depth pot. In the schematics posted by deadastronaut it is in the signal portion of the circuit controlling the LDR, but in the vero layouts it is actually connected to the output and to the LED that points at the LDR.

I have mine hooked up to the LDR and it doesn't do much. Also i'm getting a popping noise every time the LDR turns on, much like the sound of turning an amp on without anything plugged into it. I'm going to try moving it over to the LED like in the vero layout, which seems like the way everyone else has done theirs. At least I haven't heard anyone else complaining about theirs making any pop sounds...

[Manny]

You're missing the depth pot. In the schematics posted by deadastronaut it is in the signal portion of the circuit controlling the LDR, but in the vero layouts it is actually connected to the output and to the LED that points at the LDR.

I have mine hooked up to the LDR and it doesn't do much. Also i'm getting a popping noise every time the LDR turns on, much like the sound of turning an amp on without anything plugged into it. I'm going to try moving it over to the LED like in the vero layout, which seems like the way everyone else has done theirs. At least I haven't heard anyone else complaining about theirs making any pop sounds...

I've not added the depth pot yet. I briefly tried it on the signal portion as displayed in the v2 Schem but it didn't seem to do anything.
I'm going to give it a go in the position from the vero too, although I'm pretty happy with the depth as standard.

[Perrow]

I don't think you meant to connect the 555 output directly to ground.

[Manny]

I don't think you meant to connect the 555 output directly to ground.

Oh, smite one's brow, I thought it looked wierd   
The ground connection after the to the very left of the schematic (above the LEDs) should of course be omitted.

[MetalUpYerEye]

How do you make schematic diagrams like the spiffy one that deadastronaut posted?

I might have a go at drawing a schemo for this thing on a 556, since its a bit different.

[p_wats]

Bah. I've now breadboarded both schematics from scratch and the breadboard example, but still tons of ticking---even with a CMOS 555. I'm at a loss.

[MetalUpYerEye]

I'm going to try using a resistor to lower the Vcc to see if it helps with ticking. 

[Manny]

How do you make schematic diagrams like the spiffy one that deadastronaut posted?

I might have a go at drawing a schemo for this thing on a 556, since its a bit different.

Try diy layout creator. It's free and can do vero and perf too.

[deadastronaut]

nice on manny, glad you got it working...yay!...

having a few problems with my drop box account, thats why my pics have disappeared...bloody computers..arghhh...


yep diylaout creator, i use both version, version 2 for spiffy schemo's though...


for those that are curious, my voltage out of the cmos 555 is 1.8v...thats why i had to use standard leds..(with no resistors)..
superbrights will not work ok...
i have it running nice on reds or yellows...and just to be ridiculous i rigged up 7 leds and it all works fine..
will not do supers though!..

[MetalUpYerEye]

I haven't tried lowering the source voltage to reduce ticking yet but i'm wondering if the placement of the signal section in relation to the LED or IC has anything to do with it. My LED and LDR face each other about 1/4" away, directly above my IC and I still get a bit of ticking with signal and power grounds separated.

I thought of this last night when I was messing around with mine. In wiggling things around I shorted my red LED to 9v and burned it. So I grabbed my rate LED which has about 6" of tail on it and brought it over to point it at the LDR. When it was away from the board the ticking was much less, but as soon as I got it close the volume of the ticking increased dramatically.

I think i'm going to just rebuild with a CMOS 555 though. I'm going to try to keep signal and power as far away from each other as possible, maybe even separating them inside the enclosure by a piece of metal (with a hole for the LED to shine through). The 556 worked for me to get everything sorted but its a useless to me unless it can be quieted.

I'm still experiencing some sort of pop sound when my LED goes completely off. Not sure what its all about, but might need to do a small cap from input + to ground to quiet it.

[MetalUpYerEye]

I rebuilt my circuit with the CMOS 555 and i'm still getting ticking. I don't think its from the IC, but rather from the input section. It sounds like the pop you get from a crappy footswitch, only its every time the LED comes on.

Any ideas?

[Barcode80]

I rebuilt my circuit with the CMOS 555 and i'm still getting ticking. I don't think its from the IC, but rather from the input section. It sounds like the pop you get from a crappy footswitch, only its every time the LED comes on.

Any ideas?

Did you keep your grounds separated?

[MetalUpYerEye]

Yes and i've tried a 220uf cap from 9v+ to ground as well. Also tried it from signal + to signal ground and no dice.

[MetalUpYerEye]

Here's a little more info on my rebuild, in case it helps...

I used a LMC555 CMOS IC. It's wired up with a 50k pot for speed with a 100 ohm resistor in series to stop the LED's from going solid with the speed knob at full bore. I used a typical red LED aimed at my LDR and a regular blue LED for my rate/indicator. I had to put a 47r resistor on the red LED to stop it from drawing too much current and turning the blue LED off. I'm using a 9v battery that is getting a bit long in the tooth and reads 8.6-8.7v. I used a 22uf cap instead of 47uf because it evens out the sweep of the speed pot a bit more to my liking. My LDR reads 2k ohms in typical daylight and 90-110k ohms when covered with my hand (pretty much complete darkness). I used separate grounds and the circuit is very quiet except for the popping. It pops when the LED's turn on. I've tried taking out one or the other LED as well as using resistors on them and its not helping. I also tried a 220uf cap from 9v+ to power ground as well as input+ to signal ground with no results.

I've scoured the 12 pages of this thread as well as the FAQ's and debugging pages on this site. I've also looked at datasheets for the 555/556 and CMOS 555 with no luck. And of course i've exhausted all the ideas I have on how to stop it...

Hate to cry for help again but I have a bunch of time in this circuit already and its almost perfect but that sound makes it unbearable to use... 

[Manny]

Josh I use a regular NE555 and get no ticking whatsoever, wired as per my crude drawing above (note: the ground connection after the LEDs is incorrect and should be ommited).

After reading your posts I was messing around trying to get mine to tick. One interesting thing that I noted is that mine ticks if I put my battery close to my LED/LDR combo, if I move it away by a couple of inches the ticking stops completely. I'm afraid I lack the electrical know-how to explain this. Hopefully someone can explain why this may be happening?

Also, if i connect my signal and power grounds mine ticks like crazy so make sure that they're separate.

Manny 

[MetalUpYerEye]

Hey Manny,
When I built the pedal I went so far as to build the timer circuit and the signal section on two different boards to make sure that the grounds were as separate as possible. I also tried to separate everything as best I could, with the timer circuit as far away from my LED/LDR as possible. I tried moving the battery out of the box, moving it all around and covering it with my hand. Covering it seems to help a tiny bit but the difference is very slight.

I built the circuit based on the schemo and vero layout from this thread, which is pretty much what you posted. The sound is possibly acceptable at slower speeds, but when turned up faster it sounds like a farting sound... Really not gonna impress the girls at gigs... 

[Barcode80]

what kind of LED are you using? If it's a superbright, it seems I remember earlier in the thread that you have to use a regualr diffused LED for both the LDR portion and the indicator. I could be wrong though.

[Manny]

what kind of LED are you using? If it's a superbright, it seems I remember earlier in the thread that you have to use a regualr diffused LED for both the LDR portion and the indicator. I could be wrong though.

It doesn't seem to matter in my breadboarded circuit. I've tried lots of different LED sizes and brightnesses and none of them make my NE555 tick.