Author Topic: Debugging a tremolous lune, all help apreciated.  (Read 4855 times)

svstee

Debugging a tremolous lune, all help apreciated.
« on: May 30, 2009, 04:27:24 PM »
I built the Lune using this layout

Apparently Torchy's old Lune layout with values changed to original specs.

My build is acting like a volume boos right now, no trem action whatsoever. The Smooth and Depth pots both affect volume about halfway through their respective rotations.
All the voltages on the board are static, not changing at all. I used a 3mm LED and an LDR in heatshrink.

Voltages are:
IC1 (TL072)
1: 4.6
2: 4.6
3: 4.4
4: 0.0
5: 4.4
6: 4.6
7: 4.6
8: 9.3

IC2 (4558)
1: 6.8
2: 6.8
3: 8.5
4: 0.0
5: 0.04
6: 7.0
7: 8.6
8: 9.3

D1 (LED)
+ 6.8
- 4.8

LDR: Both legs 4.6


What am I doing wrong?

svstee

Re: Debugging a tremolous lune, all help apreciated.
« Reply #1 on: June 01, 2009, 03:37:15 PM »
Bump...

kvb

Re: Debugging a tremolous lune, all help apreciated.
« Reply #2 on: June 01, 2009, 04:37:56 PM »
I would undo the heat shrink on the LED/LDR to take a look at what the LED is doing. If there is no trem the light might not be blinking.
Could be a pot miswired or somethig is touchng that shouldn't be.
You could also disconnect the depth pot and see what happens. the depth pot keeps the LED from turning off when set at 0 depth.

svstee

Re: Debugging a tremolous lune, all help apreciated.
« Reply #3 on: June 01, 2009, 05:47:00 PM »
The LED is on all the time, I found out when I turned off all lights there was light peaking through the edges off the heat shrink. Voltages on the LED confirmed this I think. Smooth and Depth pots effect volume, at certain positions they dim and turn off the LED and all signal is gone.

svstee

Re: Debugging a tremolous lune, all help apreciated.
« Reply #4 on: June 03, 2009, 05:48:28 PM »
Any ideas? I can't seem to figure this one out on my own.

doc_drop

Re: Debugging a tremolous lune, all help apreciated.
« Reply #5 on: June 03, 2009, 06:35:53 PM »
I'm sure this won't help much, but that layout led to my last "recycle bin" board. I don't know if it is the layout, but I built it, and could not get it working. Being the stubborn type, I took the schematic and breadboarded it with new parts. I got it working that way and then I perfed it straight off the breadboard. In other words I didn't do a layout. I just took it part by part from the breadboard and worked out the perf layout as I went.

It works great now.

One thing I did do was put the trim pot on the exterior, as I find it is useful to adjust it depending on the depth of the effect.

svstee

Re: Debugging a tremolous lune, all help apreciated.
« Reply #6 on: June 03, 2009, 06:39:30 PM »
Well, the layout was said to be verified so I didn't check it against the schematic. Bummer, I'll have to check that out.

frequencycentral

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Re: Debugging a tremolous lune, all help apreciated.
« Reply #7 on: June 03, 2009, 07:03:26 PM »
Did you check for continuity across the track cuts? Jeez I hate stripboard. If the world ever ran out of perf, and all that was left was stripboard, I'd drill a matrix of 1mm holes in my Platinum AmEx card.  :icon_lol:
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doc_drop

Re: Debugging a tremolous lune, all help apreciated.
« Reply #8 on: June 03, 2009, 07:26:40 PM »
Yeah, I hate stripboard too. I had started the project to get my feet wet with it. But my feet got wet with something other than water... I have built a couple of strip layouts since, just to proove to myself I could. But I am definately a perf guy!

svstee

Re: Debugging a tremolous lune, all help apreciated.
« Reply #9 on: June 04, 2009, 12:55:58 AM »
Did you check for continuity across the track cuts?
I did, and I ran over the board with my trusty 7x loupe. I actually really like very, it seems cleaner to me than I can make perf. I've built a Klon and echo base on Vero, and was think about (gulp) the A/DA Flanger. http://www.aronnelson.com/gallery/main.php/v/cathexis/Veroboard+Layouts/ADA+Flanger/ADA+Flanger.jpg.html?g2_imageViewsIndex=1

Anyways, I guess I'll check out the schem and see how it looks. Has anyone built a successful circuit with this vero?

frequencycentral

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Re: Debugging a tremolous lune, all help apreciated.
« Reply #10 on: June 04, 2009, 02:49:56 AM »
There's a very similar strip layout in Gila Crisis' gallery, I think it's verified, so you could check yours against his!
http://www.frequencycentral.co.uk/

Questo Ŕ il fiore del partigiano morto per la libertÓ!

svstee

Re: Debugging a tremolous lune, all help apreciated.
« Reply #11 on: June 04, 2009, 11:32:32 AM »
I found the layout you mentioned and the one I built off of seems to  check out, I'm not 100% sure though, because of the removal of some controls.

Do my voltages suggest anything?

doc_drop

Re: Debugging a tremolous lune, all help apreciated.
« Reply #12 on: June 04, 2009, 05:52:58 PM »
And just to mention, my build based on the layout didn't work, but since it was my first attempt at stripboard, it may have been that and not the layout. I did spend a few days debugging with no luck though. I have been able to debug almost everything I have built, so it was frustrating! The only other one was a Nurse Quacky that I breadboarded but couldn't get working. I got bored trying and needed the breadboard. I'm going to try it again one of these days...Stupid circuits trying to out smart me!

svstee

Re: Debugging a tremolous lune, all help apreciated.
« Reply #13 on: June 04, 2009, 06:31:31 PM »
Did you ever get the LFO working on the build from this vero? I know that is where my problem is, since the LED is always on.

doc_drop

Re: Debugging a tremolous lune, all help apreciated.
« Reply #14 on: June 04, 2009, 07:20:32 PM »
I'm really sorry, but I don't remember. It seems like I got the LED's blinking at some point, but I am relying on some rather well used memory cells. I'll look at home and see if I have notes...

kvb

Re: Debugging a tremolous lune, all help apreciated.
« Reply #15 on: June 05, 2009, 12:54:21 PM »
The advice to trace the circuit that you have against a schematic is good.
Trying to find an error in someone else's layout is what taught me to read a schematic. It also cured me of the notion that I should even use someone else's layout.

Stripboard is hard to find errors in because the layout is not as intuitive as a pad per hole.

The audio section is working, so that's good.
The voltages sometimes don't give an answer - they just point out an error.

the LFO is not LFOing. could there be a bad cap?
Have you checked your grounds to make sure they're good?

I've torn some things apart and put them back together - as a lesson in desoldering.
The toughest part is that the error could be miniscule.

I'd just keep tracing it - the error might jump out at you after some time.

rousejeremy

Re: Debugging a tremolous lune, all help apreciated.
« Reply #16 on: June 05, 2009, 01:10:25 PM »
For what it's worth, I had a similar problem with mine. I accidentally hooked up the power backwards for a moment and he LED wouldn't blink. I had to replace both IC's for it to work again.
Consistency is a worthy adversary

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svstee

Re: Debugging a tremolous lune, all help apreciated.
« Reply #17 on: June 05, 2009, 02:19:01 PM »
kvb, I have doublechecked my grounds, and as far as caps go, I've doublechecked all the voltages on the electrolytic caps and the look good to me. The fact that the LFO is not working should make this simple to troubleshoot, but I  seem to keep hitting walls.