The Big Bad Stone Thread

[Skruffyhound]

Do you have signal when the effect is bypassed. Check your offboard wiring first.  Follow the debugging thread in the sticky at the top of "Building your own stompbox". If you don't get any joy I'll measure my voltages, but at a glance I am not seeing ground on 5 and 6. I will need to check the pinouts.
Good luck
- Aston

[malrock75]

Thanks Aston.. I bypassed the LPB-1 and came straight off the board and it works so there lies the problem. There are 4 holes near the output of the LPB  section. Does anyone know if they should be bridged with anything else? They seem like an earth to me. 

[Scruffie]

Second person to have an error with the LPB-1... i'm gunna have to look into this.

Thanks Aston.. I bypassed the LPB-1 and came straight off the board and it works so there lies the problem. There are 4 holes near the output of the LPB  section. Does anyone know if they should be bridged with anything else? They seem like an earth to me.  

However... the 4 holes should be a trimmer, without a trimmer there's nothing connecting the output of the LPB-1 to the rest of it! There's 2 holes given on the centre row for different types of trimmer.

You'd have to take the output from C17 if you didn't use a trimmer.

[Barcode80]

Grrr, got my new board, and got it all populated....

except I'm now out of a few electros I need. Crap.

[Skruffyhound]

I still haven't modded this because I'm enjoying it too much like it is. Now I'm building a small stone in between other things and the other night I had a dream that I should insert the small stone in the feedback loop of the bad stone
I guess I'll have to do it just in case it was divine inspiration

[malrock75]

Second person to have an error with the LPB-1... i'm gunna have to look into this.

Thanks Aston.. I bypassed the LPB-1 and came straight off the board and it works so there lies the problem. There are 4 holes near the output of the LPB  section. Does anyone know if they should be bridged with anything else? They seem like an earth to me.  

However... the 4 holes should be a trimmer, without a trimmer there's nothing connecting the output of the LPB-1 to the rest of it! There's 2 holes given on the centre row for different types of trimmer.

You'd have to take the output from C17 if you didn't use a trimmer.

I wouldn't be alarmed about the boards just yet as I am new to this... I was trying to find specs on a trimmer to use in all the info but couldn't find any( Domestic blindness maybe)..What would you suggest?
Thanks Mal

[Scruffie]

Any 100k Trimmer would be fine, the ones smallbear stock would work -
http://www.smallbearelec.com/Detail.bok?no=160
or
http://www.futurlec.com/PotTrim.shtml

[Scruffie]

Just came across this, EHXs original vinyl recorded audio 'advert' for the Bad Stone Phaser, a nice little demo of some of the stuff the pedal can do.

http://www.ehx.com/assets/archive/flexidisc-bad-stone.mp3

[Barcode80]

Okay, I'm at my wit's end. I'm on my second bad stone board, and I can't get it to work either. I assume it's due to the fact that none of the chips are receiving full supply on pin 8. If I'm reading my voltages correctly, my voltage drops to about 1 volt right after R50. I've swapped the resistor numerous times. I'm about to throw this through a window.

Could it be a blown opamp sucking down the voltage?

[Scruffie]

Okay, I'm at my wit's end. I'm on my second bad stone board, and I can't get it to work either. I assume it's due to the fact that none of the chips are receiving full supply on pin 8. If I'm reading my voltages correctly, my voltage drops to about 1 volt right after R50. I've swapped the resistor numerous times. I'm about to throw this through a window.

Could it be a blown opamp sucking down the voltage?

Again! This seems to be a finnicy build, but the boards are verified...
Yes it could... but also, this pedal just seems to function off a lower voltage, here are B Tremblays Voltages from his working pedal -

Code Select Expand

IC1-4 TL072

1:  3.61    8:  7.6
2:  3.61    7:  3.61
3:  3.61    6:  3.61
4:  0.00    5:  3.61

Code Select Expand

4049UB

1:  5.18    16:
2:  3.61    15:  3.61
3:  5.18    14:  5.18
4:  3.61    13:
5:  5.18    12:  3.61
6:  3.61    11:  5.18
7:  5.18    10:  3.61
8:  3.61     9:  5.18
From a 9.13V Supply.

Post your full voltages, otherwise we're just debugging blind.

[Barcode80]

Will do later tonight.

[Scruffie]

There has been some confusion over the Transistor Pin out, the Silk Screen applies to the BC239 transistor used in earlier models, not the 2N5088 listed in the parts list, I should have made this clearer so if your build is non-functioning, please check your pinout matches and always read the schematic and check datasheets before building.  

So viewed from the top of the board, with the Flat side facing the Left on the Silk Screen, Top to Bottom is C,B,E.

On another note, sockets are highly suggested for this build, it does not desolder very easily from what some people have been saying and this can be a finnicy build.

[Skruffyhound]

That makes no sense. I have a board that's doing just great with the 2N5088 stuck in it facing the wrong way then, apparently. How's that possible?

[Scruffie]

That makes no sense. I have a board that's doing just great with the 2N5088 stuck in it facing the wrong way then, apparently. How's that possible?

Depends on brand, Fairchild (Which alot of people use) Pinout would be wrong, the Phillips however would be correct, hence the need to check datasheets and schematics before building.

That or you have a magic pedal

[Skruffyhound]

It's magic. Be worth a fortune on ebay

I'd never heard of pinout variations on the 5088, one of the most versatile transistors and widely used.
My datasheets say the Fairchild and Phillips have the same pinout. So, both wrong. I can't be sure about other manufacturers, I'll check tomorrow. Mine says -J01 , who's that then?

Edit:because only half my post appeared.

[boog]

finally had some time to put this together, but the LFO isn't LFO-ing.  the guitar sounds the same with the effect engaged.  when i flip the color switch the signal is 'cut' a little bit, but nothing really happens.  i've tried flipping/switching the 5088 and that doesn't help. in fact, it operates the same if i take the 5088 completely out. i'm posting my voltage readings in hopes that they may be of help. i think there is problem somewhere around pins 12-14 on the 4049. an easy illustration of the LFO trouble is that all of my readings on the LM324 were stable except for pin 14. i did do the manual mod as listed in the build notes. i also saw something about a 100 uf cap used to jumpstart the lfo from the 9v rail to Vref. i don't understand how that would work; + side of the cap to pin 4 and - side to pin 11?  any help would be much appreciated!

IC1-IC4 (4558's)
1) 3.257      8: 6.630
2) 3.257      7) 3.257
3) 3.257      6) 3.257
4) 0            5) 3.257

IC5 (4049UBE)
1) 6.682     16) 6.681
2) 3.263     15) 3.263
3) 6.681     14) 6.681
4) 3.263     13) 6.681
5) 6.681     12) 3.262
6) 3.262     11) 6.681
7) 6.681     10) 3.263
8: 3.263      9) 6.681

IC6 (lm324)
1) 6.670      14) approx 261 mv
2) 3.260      13) 3.07
3) 3.235      12) 3.24
4) 6.687      11) 0
5) 3.252      10) 3.233
6) 3.215       9) 3.205
7) 3.205       8: 3.242

[Scruffie]

Did you use the LPB-1? It does not work, i'm in the process of updating the files to fix that.

The Manual Pot also Requires a Cut Trace, I think it's shown on the page before this, it wont work quite right untill you do so.

Check the Datasheet for YOUR 5088 and adjust it according to the schematic, you can keep turning it till you get it right if you like but it'd be better to know it was right for debugging.

Your voltages look right but quite low, how are you powering this? Battery? Is your R50 - 100R Resistor the Correct Value? It might be worth just Jumpering that, Barcodes Pedal wouldn't work with a One Spot untill he removed it... it's probably not that necessary.

[boog]

used the LPB but i have it on its own switch; nope, doesn't work but i figured i'd get the main circuit working first.

cut the bajeebers outta the trace but i'm still getting continuity between c10 and the manual switch. from what i was reading the circuit should still work though, correct? just be a bit weird.

the 5088s i use go CBE top to bottom with the flat side facing the right. so if i put it in "backwards" vs. the silkscreen it should be right.

i'm using a standard 9v 300ma adapter.  i pulled R50 out and went direct, that upped the IC voltages into the 4.5 range. 

i think i can hear a vibrato-esque thing really low if i crank my amp up, methinks it might be time to quad-check my component values.

[n8b]

I picked up one of these boards, more or less to troubleshoot the lpb-1 section. Here is the fix that worked for me:



I had to cut two traces. The point where the 1M, 100k and base meet is connected to the power plane at the 1M's leg. Cut the trace between the 1M and base, and the trace between the 100k and 1M, then add a jumper as shown in the pic. I haven't finished the phaser portion, but tested the lpb-1 and it is working nicely.

Feel free to share this info in any relevant threads.

[boog]

i still haven't been able to get this guy to fire up, so now i'm trying random things: i see that a spdt toggle is listed for the color switch. since the first pin wasn't tied into anything i used a spst. would this have any bearing on my trouble? if so, where does the 1st pin from the switch go?