No Output from Rangemaster

[68Charger]

Hello,

I just finished putting this pedal together and was met with the unfortunate realization that it's not working.

When bypassed, my guitar signal comes through very faintly and when the effect is engaged it's just a boosted level of hiss (no guitar at all). Thankfully the LED is working.

I followed the schematic closely and used an OC44 from pedalparts plus. It wasn't marked, so I kept switching the legs around until I think the voltages were correct. I checked my wiring at the switch and the jacks and they look exactly like the project pdf. Am I missing something?

Any help would be greatly appreciated!

Thanks!

[jimilee]

Welcome!!!! Sounds like its wired backwards, but we could speculate all day. If you could post clear well lit pictures we could help you more effectively. Generally the first thing you want to do is check component values and reflow all your solder joints. If you got no bypass, then we want to closely examine your wiring.

[jkokura]

If you don't have good sound when the effect is bypassed, it sounds like there's an issue with the wiring.

Did you test the PCB after it was populated but before wiring it to the switch?

Jacob

[davent]

Also link your schematic, there're lots of variations, PNP's, NPN'S, positive grounds, negative grounds...

[68Charger]

Thank you everyone for your warm welcome. I apologize for my delayed reply, I have been battling the flu since Monday (yuck!)

I have tried to go back and make sure I don't have any cold solder joints and tried taking the switch out of circuit to no avail. I have attached some photos.

I am also working off of the madbean layout with a OC44 sourced from pedalpartsplus:
http://www.madbeanpedals.com/projects/Rangemaster/Rangemaster.pdf







I really appreciate you all taking the time to help a newb out.

[jkokura]

I can tell immediatly that the problem may be in the switch. You have the switch turned 90 degrees. The lugs on the bypass switch should be horizontally flat, and you have them vertically flat.

Does that make sense?

Jacob

[68Charger]

Doh! Thank you jkokura! That solved the mystery of the missing bypass signal...I got everything re-soldered, but I am not having any luck with the wet signal. I am using an OC44 I bought from pedalpartsplus. It says "NJS1236" on the side of it and I can't seem to find a pin layout online...

I checked the voltages at the pins and they all measure in the same ballpark of -7 volts. Does this mean the tranny has opened up and is now dead?

Thank you for all of your help!

[68Charger]

Okay I just got a shipment of parts from Smallbear and decided to go with a red-dot NPN OC140 so I can daisy chain this pedal.

Since I am still trying to learn, could you guys look over these Madbean schematics and see if I have the pin out oriented correctly?







I have already switched the polarity of the wiring, but want to make sure I know how to install the transistor correctly.

Thank you so much for all of your help!

-Austin

[timbo_93631]

make sure to turn the electrolytic caps and polarity protection diode around too as it will now be negative ground.

[68Charger]

Without much luck, I decided to build another board just to make sure I didn't screw something up with the first one. I just got done and found that I am getting some output, but it requires me to crank up the gain and volume on my little practice amp to be able to hear anything.

If anything, the tone sounds like it is struggling to pass signal, but gets stronger the harder I hit the strings. It almost sounds like when you turn a tube amp off and continue playing (the sound of the electrolytic caps discharging).

I have the caps and diode switched around to compensate for the negative ground OC140, so I am really scratching my head. Should they have maintained the same orientation as the schematic calls for after all?

Does anyone want to make a little money getting this thing working? lol I am just about out of ideas....

[mattlee0037]

Yes diods and electrolytics should be flipped backwards. More good quality pics of the top of the board, back of the board, switch wiring close, and switch wiring far would be helpful for us to help locate the problem. I'm sure it's something you can fix no need to send it out!

[68Charger]

Okay cool. Here are some pics with the latest board I built.






Thank you for looking it over!

[mattlee0037]

What voltages are you getting at each leg? Sounds like it may be a bias thing.

[68Charger]

Hey Matt,

According to the pinout I posted from Bevisaudio and using my 1spot at 9.36V, I am getting:

C=.813 (red dot)
B=.867
E=.785

I got the OC140 from Smallbear and used the supplied 68K resistor for R1 and 4.7K for R2.

So that should be it right? These are supposed to bias in the 6-7V range correct?

Thank you so much. You are a life saver!

[mattlee0037]

Yes they should. Your voltage isn't getting to the transistor it seems. Check the voltage at the board 9v+ input and use the schematic to trace your voltage to the transistor to see where it drops from 9.whatever to below 1v and there should be your problem