Trem Lune LED question

[svstee]

Trying to build the infamous Lune, using this layout:
http://www.aronnelson.com/gallery/main.php/v/Gila_Crisis/Tremulus_Vero_NewRev.GIF.html?g2_imageViewsIndex=1

Looking at this schematic:
http://commonsound.org/tremulus/pcb2.4.1/schematic.pdf

I'm a bit confused because on the layout it seems to show the switch S1 connected to the LED coupled with the LDR, but I don't see that on the schem. On the schem it seems to be connected to what I believe is a rate indicator LED. I total lost here. Where do I put the switch? Does this layout even have the rate LED?

Thanks!

[petemoore]

  To tremulate you need an LED to work the LDR.
  Then there's the one at the right bottom, the bottom of the two "1k/1k/LEd across them", that one blinkx also, and seems to be influeced by the other knobs to some degree, like anything I'm sure it is related to/influences the other electronics, but didn't seem to.
  I put one in the LDR wrap, one blinking at all times as indicator of rate, then a third wired through the BPSwitch as on indicator.
 

[svstee]

  To tremulate you need an LED to work the LDR.

Yes, I understand that.

    Then there's the one at the right bottom, the bottom of the two "1k/1k/LEd across them", that one blinkx also, and seems to be influeced by the other knobs to some degree, like anything I'm sure it is related to/influences the other electronics, but didn't seem to.
   

I see that one on the schem, is it included on the layout as well?

    I put one in the LDR wrap, one blinking at all times as indicator of rate, then a third wired through the BPSwitch as on indicator.
 

So the way you did it the rate indicater LED is just another LED in parallel with the one coupled to the LDR, right?
Did you use the LED in the bottom left of the schem at all? I planned on doing what you did as well, but what about the switch (S1) on the layout?

[petemoore]

I see that one on the schem, is it included on the layout as well?
  Look at the layout, look at the schem, mull it over while you compare them.
  Build it sparsely, build it full tilt, take what you want off or leave it max-hilt.
  The GGG build schematic shows the switch on the second blinking LED.
  That switch can be a pole/throw in the 3pdt bypass [rate and on indicated with the one LED, dark when bypassed].
  Or that second LED switch can be a jumper so the rate is seen during bypass, and then use an LED wired through the 3pdt for on when on, off when bypass, typical bypass indicator.

[svstee]

Quite frankly, the rate indicator isn't a big deal for me, I just want a working tremolo. 

If I go by what the layout says, it seems to me that "S1 connects to LED D1 Anode" means it would also be connected to Depth 2 and R16. This is incorrect, right? It should be a separate LED altogether that would be used as a rate indicator.

I'm sorry if I sound redundant, but I'm just not getting this...

[PRR]

> I'm just not getting this...

Neither am I. A 45-second glance seems to show the indicator cut-out, but the actual effect running all the time.

Something aint right. With my head or that drawing.

I bet if you build it loosely, with iron and jumpers handy, you'll figure it out faster than thinking.

[petemoore]

  I built from this view:
  http://fuzzcentral.ssguitar.com/tremulus.php
  Shows the 'to LDR' LED, and another 1k/1k with LED with a switch, seems the only reason to want a switch on that second blinking LED is if it was to make bypass/on indicator that shows blinking rate when ''on''.

[svstee]

Thanks for the link! That clears things up, I think I understand it now. Build report to come soon I hope!

[svstee]

Well, I built it using the LED rate indicator found on the schem Petemoore provided, and so far, no dice. LED rate indicator doesn't light up at all, the LED coupled with the LDR lights up but just shines steady, with brightness affected by the Depth and Smooth pots. Exactly the same as the first lune I built off a different vero that I could never get to work either. Grrrr.

Debugging time! Voltages are as follow:

IC1
1: 1.51
2: 1.51
3: 1.51
4: 0.00
5: 1.51
6: 5.69
7: 1.51
8: 9.29

IC2

1: 4.59
2: 4.59
3: 4.48
4: 0.00
5: 4.40
6: 4.59
7: 4.59
8: 9.29

LED+: 7.30
LED-: 5.40

LDR: 4.59 on both leads.

Obviously I have no LFO. What should I look at?

[svstee]

Any thoughts? Could the LED wiring be the problem or is it something else?

[Skruffyhound]

I had a very similar problem building from the Fuzzcentral schem.  I'll do some more reading/testing and get back to you.

[svstee]

I've gone over this again with no luck. What am I missing? Do the voltages indicate anything to anyone? I am at a total loss here...

[Skruffyhound]

     I can't help you much with this, I quit vero because it makes my brain ache.
     I did use a new tool when I was trying to debug my pcb build. LED-resistor- length of wire - crocodile clip. Clip on to earth on one end and probe the circuit with the leg of the LED. I found that the LFO section was creating a pulse but that it wasn't getting through to the LED.
     I didn't like the schematic from fuzz central, so I began looking at tonepad's version which is much more straightforward. This led to breadboarding that schematic and getting a working lune. Since then, I've been tweaking because it was on the breadboard. To date I've added a wet/dry mix, put a non-inverting buffer on the front end, an inverted/non inverted mix and found an odd circuit bend that basically gets a cap to discharge in the signal path creating a rhythmic synth sound (great through the Gristleizer) which I have tuned using low value caps in series with salvaged pcb momentary switches, kind of a little keyboard on my breadboard.
     All of which doesn't help you, but my point is maybe you should breadboard the LFO section and fiddle with it until you get it working then refer back to your vero. I love just sitting down and stuffing components in, but have been disappointed with the result in many cases, or have had long debugging periods. I have resolved now to breadboard everything and transfer the same components to the build so I know that it was at least working to begin with.
    If it helps, even it's the tonepad schem my voltages on the 4558 are:
Pin 1 - 4.5 to 6.8
Pin 2 - 4.5 to 6.8
Pin 3 - 4.4 to 6
Pin 4 - 0
Pin 5 - 4.4 to 6
Pin 6 - 6.8
Pin 7 - 2.4 to 7.8
Pin 8 - 9
      Pots for smoothness/spacing/depth max, speed at approx. half. 9v Power source.
      Your voltages seem to indicate that you measured with pots all at min, and /or there's a some solder bridge or wrong component value going on around the 4558, but I'm just guessing.
      Go and have a look at Tonepads schematic for clarity.  Hope you figure it out. Aston

[petemoore]

IC1
1: 1.51
2: 1.51
3: 1.51
4: 0.00
5: 1.51
6: 5.69
7: 1.51
8: 9.29
  Seems like the other opamp, looking biased nicely for signal path, is the signal path opamp...?
  This one has 'wierd' voltages, if it's for the LFO, one of the pins [probably the output of the non-buffer, LFO opamp, the one with the knobs 'n caps around it] should have rising / falling voltage on it, this is the voltage the LED needs, the buffer opamp is so the LED control voltage is not loaded, follows the voltage input from the LFO and drives the needed current through itself for the LED to consume.

IC2

1: 4.59
2: 4.59
3: 4.48
4: 0.00
5: 4.40
6: 4.59
7: 4.59
8: 9.29
  This one looks biased nicely for a signal path type arrangement.
  You can test the opamp LFO, the buffer or even the LED or even the LDR to see if the LDR gets light/low resistance, which is what will allow the signal to pass more-ish unimpeded...ie when audio probing you should get signal right up to the LDR, and past it if it's under light...which it should be, for short periods...ie when the sweep is in the 'up' portion, when the LFO and LED are dimming/brightening, you should have tremolo.

[svstee]

  Seems like the other opamp, looking biased nicely for signal path, is the signal path opamp...?
  This one has 'wierd' voltages, if it's for the LFO, one of the pins [probably the output of the non-buffer, LFO opamp, the one with the knobs 'n caps around it] should have rising / falling voltage on it, this is the voltage the LED needs, the buffer opamp is so the LED control voltage is not loaded, follows the voltage input from the LFO and drives the needed current through itself for the LED to consume.

Yeah, this should be the LFO, but I can't figure out why I don't have fluctuating voltage anywhere. Anything I can look for?

  You can test the opamp LFO, the buffer or even the LED or even the LDR to see if the LDR gets light/low resistance, which is what will allow the signal to pass more-ish unimpeded...ie when audio probing you should get signal right up to the LDR, and past it if it's under light...which it should be, for short periods...ie when the sweep is in the 'up' portion, when the LFO and LED are dimming/brightening, you should have tremolo.

I can confirm there is signal at the LDR and past it when the pots are set a certain way, but there is no LFO sweep at all. Either on or off. What can I do to find out why there is no LFO?

[svstee]

Bump. Any thoughts?