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Powers up, get bypass and affected signal. But, when turning up the gain in the "none" position, the volume drops and there is no gain. Si and LED both work fine.

I tried swapping the chips, made no difference.

If anyone could take a look and see what I did wrong, I'd appreciate the help.

Before you do anything further, make sure the back of the gain pot is insulated from the board - piece of electrical tape, foam, whatever, as long as it keeps the pot frame from shorting against the solder joints on the PCB.

Yeah, made sure there was ample parking.

Try re-flowing the six solder joints for the dual gang drive pot and see if that makes a difference. They look pretty blobby to me--might be a cold joint there.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

No change in behavior. When the LED/NONE/Si switch is in either LED or Si position, gain works fine. When in the None position, volume drops.

Does the position of the 3-way EQ toggle make any difference in this behavior, other than letting more or less bass signal through?

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

It seems to work when in the LED\Si positions as well, but not noticeably in the None position.

also, when in the none position and using a heavy pick attack, I get a brief burst of noise that quickly fades out to the low signal. That clean sound is fantastic, though..

Yes, I understand that. I'm asking about the effect (if any) of the Normal-Thin-Fat EQ toggle when the clipping toggle is set to None.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Sorry for not being clear. The EQ toggle does not have a noticeable effect when the clipping toggle is set to None.

Further clarification, please--does the volume decrease gradually as the drive is turned up, or is it a step change at some point? And when you say "no gain", do you mean that the signal has no added distortion? I'm asking a lot of questions because I've never encountered this particular issue before.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

This is a very odd problem. It simply doesn't make sense that the pedal would work as expected in Si and LED modes, but not in NONE. The only thing I can suggest is to remove the toggle switch and see how it behaves then.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

The volume decreases in a smooth/gradual manner. It behaves almost as if the entirety of the distorted signal is being shunted to ground across the full sweep of the gain pot. When the gain pot is turned completely to the left (CCW), the clean sound is clean and full. as the gain knob is turned to the right (CW), the clean volume drops instead of being replaced by the distorted signal. In both Si and LED mode, there is distorted signal across the full sweep of the gain pot, and that distortion increases as the gain pot is turned right (CW)

yes, by "no gain" I mean that the signal has none of the expected distortion.

I can record some clips if that will help to explain what I'm seeing.


I can give that a shot tomorrow. When using SI and LED, should the signal still be 100% clean with the gain pot turned fully to the left (CCW)? It is not clean, I am just not sure what the correct behavior is..

Thank you both for your assistance!

That could be useful. Please do so.


Pretty close to it. Half of the dual gang drive pot is a blend control that splits the signal between a clean path and a gain path; the other half of the pot increases the gain in the latter path as more signal is sent through it. So with the pot fully CCW, it should be essentially all clean signal. There's a little change in the character of the tone through the back half of the circuit (it goes through another three op amp stages plus the tone and volume controls), but it remains very clean.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Do you have access to a multimeter and know how to use one? I think it would be useful to check the resistance through both sides of the dual gang drive pot.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Removing the switch didn't have any effect on the behavior I'm seeing.

The only thing that changed in the sound clips are the position of the clip switch and the position of the gain knob. Clips:

"None" position, gain at full CCW:
http://www.coloredvinyl.com/media/pony/none-CCW.mp3

"None" position, gain at 12:00:
http://www.coloredvinyl.com/media/pony/none-12.mp3

"None" position, gain swept from full CCW to full CW:
http://www.coloredvinyl.com/media/pony/none-CCWtoCW.mp3

Si position, gain swept from full CCW to full CW:
http://www.coloredvinyl.com/media/pony/Si-CCWtoCW.mp3

LED position, gain swept from full CCW to full CW:
http://www.coloredvinyl.com/media/pony/LED-CCWtoCW.mp3

Removed, on the coffee table position, gain at full CW:
http://www.coloredvinyl.com/media/pony/NoSwitch-CW.mp3



the top row are the inner spots, the bottom row are the outer. checked in the 200k range using the points on the pot itself, shaft facing towards me. got the following readings:

CCW:
p1-p2:0 p1-p3:1 p2-3p:1
p1-p2:0 p1-p3:100 p2-3p:100

CW:
p1-p2:0 p1-p3:1 p2-3p:1
p1-p2:100 p1-p3:100 p2-3p:0

That inner row seems like a problem to me..

The drive pot resistance measurements agree with those for my fully functional Green Pony.

Try swapping the positions of the two op amps (NOT the 7660S charge pump!) and see if the pedal's behavior changes.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Please take voltage readings on pins 4 and 8 of the dual op amps.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

No change in behavior.


Both show 17.2v

Please clarify. Checking those two pins on two separate op amps would yield four measurement results. Are you saying that you saw 17.2VDC on all four pins??

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Apparently I misunderstood. I checked the voltage with the positive lead on pin 4 and the negative lead on pin 8. Was he asking for the voltage from each of those 4 pins to ground?
if that is the case, both chips had the same readings:

4 - 8.4
8 - 8.7

To measure the voltages for the Green Pony you need to ground the black probe to the sleeve of either the input or output jack. One of the corner screw holes of the enclosure will also work. This is because you are going to measure for a positive and a negative voltage.

With the black probe grounded touch the red probe to pin 8 of IC1 and then IC2. Next place the red probe on pin 4 of IC1 and then IC2. On my GP I get +9.47V on pin 8 and -8.75V on pin 4.

_________________
"It’s your soldering."

I think if you recheck, you'll find that the pin 4 reading was -8.4V, which makes sense. That's why you saw a total voltage drop of 17.2V across pins 4 and 8; 8.7 - (-8.4) = 17.1V, the same value within measurement error.

Suggest that you check the other pin voltages on both op amps, referenced to ground.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thank you for the clarification. Re-checked, both still matched:
4 -8.38
8 8.79

I didn't see the negative in there, apparently I need a better light in my workspace.

Any chance to take those additional op amp pin voltage measurements yet, i.e 1 thru 3 and 5 thru 7? They should all be right around 0VDC referenced to ground, though they may read a few mV on an auto-ranging multimeter.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Heh, thank you for following up.. I totally missed that you wanted the rest of the pins. I am apparently not good at the reeding and the comprehensioning.


these are the readings off both chips, first is the one closest to the LED:
1: 6.52
2: 6.80
3: 6.79
4: -8.39
5: 0
6: 0
7: 6.80
8: 8.8

1: -6.93
2: .05
3: .01
4: -8.4
5: 0
6: 0
7: -.01
8: 8.8