Build Your Own Clone Message Board

So, I put together a Triangle Large Beaver and it has a strange issue with the Tone control. The pedal works well but the output is pretty low when the tone stack is in circuit. Also, the volume is effected by the Tone control. It gets quieter with the knob at noon but louder when turned up or down from there.

With the tone stack bypassed, it sounds glorious. Sounds good when Tone is activated too, just quiet.

I have double checked all of the components. All resistors and caps are where they should be. The Tone pot is the B100k and the others are the A100Ks that came in the kit. Reflowed all of the solder joints.

I know the issue is isolated to the tone stack portion of the circuit but I'm at a loss for a solution. Possibly a bad Tone pot? Any thoughts?

There is a very noticeable loss of volume when the tone stack is active vs. when it is bypassed, since you're not losing signal through the passive tone controls. But it shouldn't be extreme, and your description of the volume going through a minimum at the tone control midpoint doesn't sound normal at all.

Please provide a set of photos--they need to be LARGE, well-lit, well-focused shots of BOTH sides of the PCB and all of the jack and switch wiring. You can post them to a publicly accessible hosting site and display them here or post them directly here using the forum's file attachment function (found below the main posting text box). If you use the latter, know that there is a 1 Mb size limit for image files, so it may be necessary to reduce their dimensions or their color depth to get them below that size limit. Any of a number of image editing applications will allow you to do this. I often recommend IrfanView for this purpose, since it is free and very easy to use.

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

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

Thanks for the reply. I will get some photos up but it will take a few days. (Phone/camera issues.) Until then, do you know which caps and resistors make up the tone stack? I have looked for a schematic but can't seem to find one.

You can find the schematic here, and I'd say that the tone section is between SW3 and SW2.

Thanks eponymous! I'll take a look and bust out the DMM when I get home tonight. Much appreciated!

Thought I should update this just in case anyone experiences the same problem as me. I had gone over my build several times and couldn't seem to find the culprit responsible for the issues described in my original post.

As it turns out, Q4 was defective. Replacing that component solved everything and the Triangle is working beautifully.

Thank you to everyone that provided input here.

Edited to add: Since completing the first Triangle Beaver and having issues, I ordered a second kit and built that one. It kind of works but the Sustain control is behaving similarly to the Tone control in my first attempt. There really isn't much effect until the Sustain control is on max and it's really not like a Muff circuit.

I am confident that every solder joint is solid and component placement is as it should be. At this point, I am suspecting another defective transistor and am beginning to wonder what the failure rate on these transistors is. If this kit has a bad one too, that doesn't instill much confidence in the rest of them.

Any thoughts or input on the failure rate of the transistors in the Large Beaver Triangle?

Glad to hear that you got your first one working!

Could it be another bad trannie? Sure, that's possible. I don't think anybody has been producing those in years, and it's not surprising that as NOS reserves are used up, failure rates increase. But it could also be something as simple as a weak solder joint or a component out of place. I would suggest three things:

1. Post a good set of photos of the build. They need to be LARGE, well-lit, well-focused shots of BOTH sides of the PCB and all of the switch and jack wiring.
2. Take a set of DC voltage readings on the collector leg of each of the four and post the results here. If you have a bad tranny, that's likely to show up in the results. Guidance on how to measure DC voltage is included in this video: https://www.youtube.com/watch?v=XRFtlUn4eBg
3. I normally suggest working through THIS PROCESS, but if you're sure that your soldering is solid, you may wish to pass on that.

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

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