'LIGHTWAH'

[Jdansti]

Edited due to erroneous information.      

[midwayfair]

Folks, remember, that schem has a mistake. The 1590 going from lugs 1 and 2 of the speed pot goes to Pin2, not pin1 as currently shown, and the tremolo switch doesn't work.

HYSH, Silly question but ... are you in LFO and not manual mode? Pics of the board?

[Jdansti]

Folks, remember, that schem has a mistake. The 1590 going from lugs 1 and 2 of the speed pot goes to Pin2, not pin1 as currently shown, and the tremolo switch doesn't work.

HYSH, Silly question but ... are you in LFO and not manual mode? Pics of the board?

Jon,

Thanks for the reminder. It looks to me that the layout he's using has been corrected: http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=45818. Do you agree?

[haveyouseenhim]

Thanks for helping guys     jon's comment got my hopes up then john's crushed me   here's some pics

[Jdansti]

What are the values of C1, C4, and C8 on your board? They appear to be tants. Check the values and the polarity of these.

The resistors that I can see look good, although I can't see the upright ones including the pairs that you put together to make larger resistors. You might want to check these as well. 

[deadastronaut]

Folks, remember, that schem has a mistake. The 1590 going from lugs 1 and 2 of the speed pot goes to Pin2, not pin1 as currently shown, and the tremolo switch doesn't work.

HYSH, Silly question but ... are you in LFO and not manual mode? Pics of the board?

Jon,

Thanks for the reminder. It looks to me that the layout he's using has been corrected: http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=45818. Do you agree?

thats is correct, thats the final build design i verified!...

[midwayfair]

Folks, remember, that schem has a mistake. The 1590 going from lugs 1 and 2 of the speed pot goes to Pin2, not pin1 as currently shown, and the tremolo switch doesn't work.

HYSH, Silly question but ... are you in LFO and not manual mode? Pics of the board?

Jon,

Thanks for the reminder. It looks to me that the layout he's using has been corrected: http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=45818. Do you agree?

thats is correct, thats the final build design i verified!...

I was just reminding them in case he checked his layout against the schem, so he didn't think there was something wrong with the etch.

[haveyouseenhim]

I'm going to post detailed pics of the rebuild just in case the same thing happens.  Here's the new pcb. I tested the continuity of all the traces and it's all good.

[scuzzphut]

I got this finished and working well after some experimenting with LEDs and LDRs.

Thanks to deadastronaut for a great scheme.


One thing - In a fit of bravado, I tried the volume/trem mod. When I switch it over from wah to vol, I just get silence.
Anyone get this part working ??

For the record -
(1)  I cut the short track between C2 and C5
(2) The C2 side of the cut goes to the centre of the switch.
(3) The C5 side of the cut goes to one end of the switch - when these are made, Wah mode is on - working fine.
(4) The other end of the switch goes to +ve side of C4 - pin 1 of IC1.


Helpsies ??

[haveyouseenhim]

so I did a total rebuild and i got the same problem   this is the layout i went by. i followed it perfectly  it's the one from page 29. my heart hurts from the frustration i had to take my anti anxiety meds

[midwayfair]

HYSH, does your manual mode work?

I'll take voltages tomorrow evening. A little late for me now.

Wait a tick ... what's your value of R12, the resistor between Q1 and D2?

[haveyouseenhim]

Manual mode works just fine. The LFO just won't O!  

R12 is 100ohm  brown black brown. I tried cutting the trace between pins 6&7 on ic2, just tinkering trying to get any reaction, and it made the lfo led brighter but it didnt help so I re-soldered the pins.

I'm feeling much more calm and collected after taking a break (and a xanax)   which is effective because I just spilled my box of a few thousand diodes and opamps and I didn't spout out even one curse word

[scuzzphut]

HYSH - Check the polarity of your LEDs.  The + markers are hard to see on the layout and I had one in back-to-front when I first built the PCB.   Also - I found that shorting the 100R resistor in front of the LED improves the intensity of the LFO mode.

[haveyouseenhim]

^that was the first thing i checked the first time i built it. all of my polarities are correct according to the layout. im getting light from all 4 leds, just no oscillation

[midwayfair]

What about your standing resistors near IC2? the north one is 6.8K, and the metal film one is 1M? Have you verified the proper connections against the schematic (the correct one, before the trem switch was added) with a multimeter?

[scuzzphut]

^that was the first thing i checked the first time i built it. all of my polarities are correct according to the layout. im getting light from all 4 leds, just no oscillation

That's right, I forgot - you're getting a solid light instead of pulsing. I had that issue too, but I found a short between two pins on IC2.
Not sure where to go next - maybe swap out the IC ?   

Post  your IC2 voltages and I'll compare them with mine - might help.

[haveyouseenhim]

in order 1-8 of ic2

4.26
4.20
4.10
0
4.16
4.15
4.15
8.06

@ Jon

can you re-post the correct schem? there's a million in this thread

heres some pics.  im aware that the 6.8k are 68k in the pic, but i caught that and used 6.8k

[midwayfair]

Reposting -- Henry, please confirm that this is the most recent, definitely-correct iteration prior to the tremolo switch being added? [At any rate, this is the schem I used for my LFO-only version]

HYSH, it's not relevant and it's not affecting the LFO, but your tepees are 1.002M. You'd need a 200K resistor; you have a 2K.

[deadastronaut]

yep thats the one!..

[haveyouseenhim]

now i just feel silly  

*Edit* i fixed the 1.2m resistors