UPDATE: Bad Stone build works!!

Started by bluesdevil, January 01, 2006, 04:46:18 PM

Previous topic - Next topic

StephenGiles

The connection between pins 3 and 10 or rather as I suspect, the lack of it, could be your problem. As I remember from building this years ago, there is no room for manoevre (spelling??) on this one, it either works or it doesn't - even if one component is missing or wrong valued.
Stephen
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

bluesdevil

I'm getting more stable readings on IC F with rate knob maxed, but different depending on if the signal is broken up or phasing smoothly. Here are some new readings with all the chips in place and guitar plugged in:

IC F:
broken up sound:
p1-.671
p2-1.742
p3-1.731
p10-1.731

with signal pushed through and phasing:
p1-1.7
p2-3.6
p3-3.6
p10-3.6

Sometimes when I fire up the circuit, the sound isn't broken up at first, but stuck on a phase notch and not sweeping. When I short pins 3 and 4 on IC F with my DMM probe, it starts to sweep.  Still a big chunk of low end is missing. 
     I tried changing out r4, r38, c10, r26, r44 and r39 with no improvement and pins 3 and 10 are definitely connected with no shorts between the other pins.
           One last thanks to all who took the effort to help, I really appreciate it. Unfortunately, I have to finally admit to myself it's definitely something beyond my ability to mend even with the clues given.
Sir H C, if you're really up for it I'd be glad to send it over... check your PM box.
        Goodbye pride and hello Bad Stone!!!!!
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy

Zero the hero

The layout is verified, it has been built and checked by various people.
I'll read the voltages of IC F on my Bad Stone and put in this thread (tomorrow!).
What transistor are you using? Try different 2N5088 or 2N5089 and see what happens.
Sorry If I had not replied untill now.

bluesdevil

Thanks for joining in this thread, Zero the Hero!!! I used 2n5088 and then replaced with 2n5089 with no change. The phasing effect is superb with a great variety of sounds..... the best I've heard, but still with volume/low frequency cut and trouble with getting signal to push through when first activated. After many hours of debugging, a  real mystery to me.
         To hell with DIY ethics on this one..... it's being shipped off to professional hands tomorrow!!
         
       
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy

Zero the hero

I checked the voltages on IC F.
They have been measured with the speed pot fully CCW (slowest phasing), manual switch to OFF (the LFO drives the sweep). Resonance pot and vibrato switch are not directly involved with voltages with this chip.
So, here they are, pin-to-pin:
1: 1.73 ~ 2.25
2: 3.29 ~ 3.56
3: 3.29 ~ 3.56
4: 7.54
5: 2.39 ~ 3.48
6: 2.50 ~ 3.48
7: 1.50 ^ 4.70

8: 1.50 ~ 3.40
9: 1.59 ~ 3.33
10: 3.28 ~ 3.55
11: 0
12: 1.55 ~ 4.27
13: 3.15 ~ 3.38
14: 6.20

Everything (almost) oscillates and it seems around a sine wave. Pin 7 follows a sawtooth wave (slowly increases then abruptly return to 1.50V).
NOTICE that when I tried to measure voltage at pin 9, the oscillator LOCKS UP to 3.38V! In order to restar the oscillation, I had to turn power off, wait a bit and re-power the circuit.

Zero the hero

Repeat the reading with the speed pot fully CCW.
Different readings on pins 3 and 10 are due to oscillator lock up.
You said you changed C13 (tantalum) with 2 caps connected in series. How did you connected them?

bluesdevil

Thanks Alex. I already mailed it to Sir H C, so hopefully those readings will help him with a speedy debug. Later in my debugging effort I pulled out the series caps I had for c13 and tried just a 1uf with no difference.
     I also had to parallel a couple of resistors to get the 150ohm, but I made sure to measure it with my DMM before soldering.... it was 147ohms.
     I'll make sure to post an update if this thing ever gets up and running 100%!! Either way, this thread will make a good reference for future builders debugging it.
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy

bluesdevil

Just got the circuit  back in the mail today. Thanks to the "hands on" help of fellow forum member Sir HC, it works!!! Here's how he fixed it:
http://www.elixant.com/~stompbox/smfforum/index.php?topic=42189.0

Really weird, but made it work. The volume is still low in the phase mode, but that seems to be a standard  flaw, like with the Small Stone. I'm tacking on a Stratoblaster booster on the output for a fix.
       At the end of this I feel a bit lame for not getting it to work properly myself, but I'm truly grateful for the amazing efforts the more experienced builders and engineering  pro's put into helping knuckleheads like me build these crazy sounding boxes.
           Hats off to the Topopiccione Electronics site, Sir HC and this forum . Now excuse me while I riff on the Stones song "Shattered" with my new pedal, Shadoobie!!!  :icon_twisted:
"I like the box caps because when I'm done populating the board it looks like a little city....and I'm the Mayor!" - armdnrdy