No sound from Orange Squeezer

[spargo]

I've breadboarded an Orange Squeezer. Bypass works fine, but zero sound when I engage the pedal. There's just a bit of hum when I crank the volume up. Comparing to the references it's obvious that my transistor voltages are incorrect, but I've triple checked the board layout. I've used the 2N5457's as in the schematic. Here are my voltages:

9v 9.13v

IC - 4558
1 5.0v
2 5.0v
3 4.9v
4 0v
5 0v
6 8.6v
7 8.6v
8 9.14v

Q2 - 2N5457
D .355v
S .355v
G 0v

Q1 - 2N5457
D 9.14v
S .457v
G .354v

The only idea I have so far is my inability to read the schematic correctly as far as the transistors go (why can't they be labeled "D S G" on the schematic?).  I've assumed on the schematic that the leg with the arrow is the gate, the source is the leg closest to the arrow on the schematic marking and the remaining leg is the drain. Is this correct? Any other ideas?

[LucifersTrip]

I've breadboarded an Orange Squeezer. Bypass works fine, but zero sound when I engage the pedal. There's just a bit of hum when I crank the volume up. Comparing to the references it's obvious that my transistor voltages are incorrect, but I've triple checked the board layout. I've used the 2N5457's as in the schematic. Here are my voltages:

9v 9.13v

IC - 4558
1 5.0v
2 5.0v
3 4.9v
4 0v
5 0v
6 8.6v
7 8.6v
8 9.14v

Q2 - 2N5457
D .355v
S .355v
G 0v

Q1 - 2N5457
D 9.14v
S .457v
G .354v

The only idea I have so far is my inability to read the schematic correctly as far as the transistors go (why can't they be labeled "D S G" on the schematic?).  I've assumed on the schematic that the leg with the arrow is the gate, the source is the leg closest to the arrow on the schematic marking and the remaining leg is the drain. Is this correct? Any other ideas?

It looks like you got the DSG correct


I'll tell you what's funny. I built about 25 -30  pedal circuits [simple fuzz/ effects]  so far and amazingly every time I got no sound it wasn't fully my mistake. I would always catch my mistake before I soldered in or placed the final piece in the breadboard.

There were 6 times I got no sound and I clearly remember each one: 2 times it was bad schematics [Fuzzrite, Op Amp Muff Fuzz] 2 times it was a bad resistor[100k both times], 1 time is was a bad pot [100k Alpha] and lastly [this week] it was a bad clip lead I just bought...I'd rule out a bad schematic here, but I'd re-check components & externals.

Secondly, to simplify things don't wire the  switch until you have it running.

Thirdly, check to make sure you have continuity between connections on the breadboard.

Also, alot of people use audio probe:
http://www.diystompboxes.com/pedals/debug.html

...and this is after you do the standard debugging.

...and remember the schematic:

[spargo]

Got the audio probe going, but noob question here: where is the signal path on the orange squeezer?  At what points should I expect to have a signal?  Also, is it likely I could have a bad transistor since those are showing incorrect readouts?  Perhaps the one that's directly connected to 9v.

[jkokura]

I would try just turning the transistors around, just in case.

After that, with the Audio Probe, start at the output and just follow connections back to the input. You can also start at the input and follow the connections to the output if you prefer. Obviously, you will get no signal at ground, so don't bother check that side of a component, and you shouldn't get signal at power either, so avoid that side of a component also. The signal is right in the middle of ground and power.

Jacob

[spargo]

Got it...the 2N5457 that was connected directly to 9v was shot (hence the low readings on the transistor).  I replaced it and it worked right away.  Now to figure out this trimpot...I hear a 25-turn trimpot is better for accuracy?

[MartyMart]

A multi-turn trimpot will help, I didn't use one and there is only a few mm's of movement
between "no sound-clean signal-distortion" !!

I got it sounding right but a multi-turn trimpot would have made life easier.

MM