Author Topic: Hot Fuzz Pro Tonebender MKII problem  (Read 415 times)

esurreal

Hot Fuzz Pro Tonebender MKII problem
« on: January 17, 2021, 01:44:54 PM »
Hey there. I've built this pedal a few times in the past and haven't had any problems. For some reason I can't get the one I'm working on currently to work. I used an audio probe and found that I don't have sound after the 10K resistor connected to the Q1 collector. I can hear it on the collector side, but not the side connected to power. I've checked and re-checked for cold solder joints and bridges. Any other ideas? My Q3 collector is also reading very low a .407V. By the way my Q3 collector, emitter, and base all read .407V. Not sure why that's happening.

Schematic:
https://www.diystompboxes.com/smfforum/index.php?topic=51626.0

antonis

Re: Hot Fuzz Pro Tonebender MKII problem
« Reply #1 on: January 17, 2021, 02:04:35 PM »
I don't have sound after the 10K resistor connected to the Q1 collector. I can hear it on the collector side, but not the side connected to power.

Quite normal.. :icon_wink:
(power supply sources exhibit almost zero impedance so they short signal to ground..)
Amplified signal goes from Q1 Collector into Q2 Base and and a new amplified one goes from Q2 Collector into Q3 Base and so on..

By the way my Q3 collector, emitter, and base all read .407V.

Can we see some pics of your build..??
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

PRR

Re: Hot Fuzz Pro Tonebender MKII problem
« Reply #2 on: January 17, 2021, 02:53:50 PM »
....my Q3 collector, emitter, and base all read .407V.

Transistor is a dead short.
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esurreal

Re: Hot Fuzz Pro Tonebender MKII problem
« Reply #3 on: January 17, 2021, 10:41:01 PM »
You think the transistor is bad?

I didn't realize it but the j201 is meant to be placed directly onto the board without twisting the legs around like the original schematic. I now have sound, but it's not fuzzy. It's a dull tone. Almost clean, but a little muddy.

I had a pcb made for this circuit. Here's the board schematic. I can't find any faults.

« Last Edit: January 17, 2021, 10:52:12 PM by esurreal »

antonis

Re: Hot Fuzz Pro Tonebender MKII problem
« Reply #4 on: January 18, 2021, 03:37:59 PM »
I had a pcb made for this circuit. Here's the board schematic. I can't find any faults.


Tracks width and clearance(spacing).. :icon_wink:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Big Monk

Re: Hot Fuzz Pro Tonebender MKII problem
« Reply #5 on: January 18, 2021, 06:12:42 PM »
I had a pcb made for this circuit. Here's the board schematic. I can't find any faults.


Tracks width and clearance(spacing).. :icon_wink:

This is the reason I tend to draw circuits “freehand” in Diptrace. I have better luck than with trying to allow the PCB design program to make the initial guess at the board from a schematic.

I was think the same thing when I saw it. Unless I need to really cram stuff into a design, I usually keep 2x the trace width between traces and at least 1x trace width between pads.
“We are what we repeatedly do. Excellence, therefore, is not an act, but a habit.” Aristotle

"Beneath the bebop moon, I'm howling like a loon, for you..." Marc Bolan

esurreal

Re: Hot Fuzz Pro Tonebender MKII problem
« Reply #6 on: January 19, 2021, 06:34:57 PM »
Hmm, never used Diptrace, I'll have to look into it. I used Eagle for this. It was my first time using a computer program to make a PCB. I definitely made a few mistakes with component sizes, but I've sorted it out now.  I also hand connected all the connections to the components within the program and then had Eagle do an auto route, so it wasn't completely guessing. I'll try re-adjusting the spacing and have another run at it. Fortunately these boards are cheap, so I'm not out much moolah.

Thanks for the suggestions!