SOLVED MUFFLER NOISE GATE NOT WORKING

[morgandorfer5150]

After quite a bit of troubleshooting I have solved the issue and the muffler noise gate works beautifully! IMPORTANT! Q3 is backward in the board and on the build diagram! Install it 180 degrees from it's shown state. All other components values and polarity are good. If your muffler build is not clamping and is instead just making some low farting noises when wide open, reverse the direction of the 2n5485 FET! Works fantastically now! Great gate!

 

[Chuck D. Bones]

Mr. PedalPCB should weigh-in here. The board photo on the website shows Q3 oriented correctly for a 2N5485. The board photos aren't always up-to-date. Compare the photo to the parts & traces on your board around Q3.

Are you positive that your JFET is 2N5485? There are tons of counterfeit parts for sale, particularly JFETs. Unless you bought it from a reputable supplier, the pedigree is questionable. BTW, a high score on eBay does not make someone a reliable semiconductor supplier.

 

[morgandorfer5150]

I think so, I purchased it from Tayda and I've never had issues with thier parts before. All I know is that the board shows Q1-3 all oriented in the same direction and when I did that, the gate would not clamp. More, it's sounded like what I imagine force reverse biasing a junction would sound like, as if the signal was trying to push through and couldn't. Did yours work in the orientation shown? Once I reversed Q3 it worked perfectly! I just used it today for sunday services Sounded great! I could be missing something I suppose, but I hope not! I went through the schematic and checked every other components probably five or more times. Then again, we are all human so...haha could just be I goofed somewhere. I'm not a pro by any means, but over build about 16 different pedals so far. This is the first time I've found a possibility reversed component. Comments welcome! I'm just trying to learn.

 

[Robert]

Mr. PedalPCB should weigh-in here. The board photo on the website shows Q3 oriented correctly for a 2N5485.

The board is still laid out for a 2N5485 with DSG pinout, nothing has changed.

 

[morgandorfer5150]

Well, I must have messed something else up then I guess. Snapped some pics this morning of the build out of the box. I used sockets for Q1&2 because I wanted to be able to try different parts in case some worked better than others as a pair (I didn't know if a matched set would really matter). If I'm missing something obvious please let me know and then I'll take the thread down. Thanks everyone.

 

[tat2dadig]

I'm having the same issue. Has anyone got anywhere with it? I tried reversing q3 signal comes through does not clamp down. Standard way for q3 and it has a low fart. ????

 

[Chuck D. Bones]

Try starting a new thread, with pix of your build, etc.