MXR NOISE GATE from Tone Pad NOW IT WORKS!

[KMS]

Ok maybe I should not build the noise gate for my first pedal but I can’t justify building anything else until I clean up my existing pedals’ noise.

I made my own board, it turned out great.  Drilled all the holes .032 inches, turned out great, and didn’t even break a drill bit. Checked traces for continuity, OK.  All I have is an ohm meter and a 301 electronics project kit and soldering iron.

Hooked up guitar and the sound is muted real strong, almost no signal going to amp. Can’t get signal to go to amp.  Checked everything 10 times and found a 680K resistor where a 680ohm should be. Replaced it.  Took out all the caps and tranys. Replaced the caps, and put sockets on for the new tranys.   I don’t really know how to debug other than replace parts with new ones.  I used the 2N 3904; and one 2N 5485.  Used 4558 IC, dual op with socket also replaced it with a new one.  I wired a bypass toggle into layout and I get good sound through the bypass toggle.   I have gone over the board 20 times and can’t find any bridges, looks good.  It won’t release.  What do I do next?  Note: when I turn the audio pot I notice a very slight increase in volume level and when I turn circuit off it releases for split second.


SEE POST FIVE "NOW IT WORKS"

KMS

[toneman]

U probably have a wiring error.
going over 20times doesn't help.
MayB try a different pair of eyes.
Check all nodes 2 B sure U have the right # of connections.
replacing parts with others is  not repair/troubleshooting.
On a noise gate, it's "on" in the presence of a signal.
Usually, this is done by rectifing the signal and then
using this "control" voltage to turn on/off a switch, or gate.
Can U turn the "gate" on/off manually???
MayB check 2 C if, when U strum, U get a changing voltage
after the rectifier.
Changing the parts having no effect just points to a wiring error.
Got a good pwr supply???  Is battery good (above 8.8VDC)??
Is the signal *actually* geting 2 the pcb???
This could B a sw wiring error.
Eitherway, U have a wiring error....
wish I could help U more, but my probes aren't that long...

[waldo041]

Maybe this will help. you'll use it again and again and again. peace waldo

http://www.diystompboxes.com/pedals/debug.html

or

http://www.geofex.com/fxdebug/fxdebug.htm

http://www.geofex.com/FX_images/audioprb.gif

[KMS]

It was a wiring problem.  I did not have the guitar jack grounded to the PCB.

Also the after fixing the ground the volume was still very weak (attack and release worked well) so I replaced the 2N5485 (again) and it got a little louder (easy since I had the tranys in sockets).  So I tried several 2N5485 trnys (all new) and one of them worked and the volume is up to almost the same as the true bypass (maybe exactly the same).

So my first pedal works.  Now I'm happy, but it is still a little choppy on the attack. The release works great.  I say this but I understand that when the choppiness is going on (at the end of my guitar signal) both the attack and the release are causing the problem.  I've read that a 68pf cap will reduce the problem but the build report does not say where the cap should go except at "the threshold".  I got a good idea where that is but I think I will need to cut a trace or two to experiment with it and I hate doing that not knowing for sure which trace to cut, and if I even need to cut a trace and could fix it at the ground trace by inserting a cap between the circuit there. I'm not sure that the info is good either.  There are some posted mods by Francis that might do the trick < longer and shorter release time<>longer attack time<> and attenuation>.  I'm not sure what to do next and I don't know if I want 4 pots sticking out of the box. (Maybe I'll use trim pots) But if the pedal has controls they should be on the outside of the box (my opinion).

Any insight you can give is appreciated.

Hey I made the trany sockets out of IC sockets cut down. You probably already discovered that since you’re obviously experienced at this stuff.

Thanks for your help and your attention to my post that was a couple of days old.


KMS trying to stop the noise.

[KMS]

Hey Thanks everyone!

In the box and finished for now.   My supplier said that I could come and test all of the transistors he has in stock and pick the ones I like best as long as I do no damage.   He said he knows that some of the 2N3904's he has will show an hfe of 150 and that will smooth the decay out.

When I go in for my next project I'll get some ruby transistors.  He's got about 200 2N3904's in the bin and he said he's got more in the back.

One thing is for sure, transistors are not all created equal and that is definitely the most significant thing I learned from my first pedal.

Also, the box was a lot harder to make than I thought it would be.  Actually, I think the box was harder than the circuit, but it was worth it. Looks real cool, 4"x6"x1.5", nothing on the sides or the front, Black with Silver graphics and a true bypass, MOM, three pots, on/off toggle, AC adapter, and 9V rechargeable Nickel Metal Hydride that pops in and out of the box with slide-in mount.

I would post a picture but I don't know how to do that.



KMS looking for a new project.

[KMS]

I got two 2N3904s hfe 150 and one was teetering between 150 and 149.

Put them in the sockets and was real smooth but a tad of pulse on the close of the gate.

Then traded places with the two 2N3904s putting the lower hfe at the input Q1 position.  That was it, smooth as silk.  Still a smidge of pulse at the close, sometimes, but I can take it out by adjusting the sensitivity up a little.  I have sensitivity on lowest possible setting for max sustain.  Also, I'm testing in a small room sitting way too close to my headphone setup as my amp is at our practice barn, (yeh we got a barn, with heat).

I have to hold the guitar at just the right angle to keep the feedback down from the pickups.  I know that is also triggering the gate somewhat and will completely disappear when I'm hooked up to the amp.  This pedal is a rock solid noise gate and I recommend it to anyone that wants to stop their noise in between notes.

Surprise!!!  Now I know how Jimmy Hendricks did the intro to FOXY.  He had some kind of gate that muted the output signal, probably a noise gate because I accidentally discovered it last night with my noise gate.  Yep the gate is also a good effect because it is predictable and you can play the mute into your music especially for pick muffing sticcato.  It really accents the notes and total silence is heard between the shortest notes I can play without chopping the note off before I want it.  

Back to practice.

KMS I love it!

[STOMPmole]

The 'gate' that Hendrix used to mute the output signal on Foxy Lady is called a "Volume Potentiometer".  It comes as standard equipment on a Fender Stratocaster  :lol:

[KMS]

How about that!

I knew it, I just did not know until now.

KMS

[Paul Perry (Frostwave)]

"DIY with-a-little-help from my freinds
DIY with-a-little-help from my freinds"

KMS, that is the best sig I ever saw!
Gonna sing that while I solder..

[KMS]

Really? A good sig?

Thanks!

I guess I’ll keep it.   It was the first thing I could think of. We don’t play any Beatles but their music is always on my mind, too much sometimes.

Hooked my homemade noise gate up to the amp tonight and, yeeeeessss, it works better on the amp than the head set in my room.  My band dogs were glad to see that I can build the pedal, and now they have all kinds of ideas about what “I” can do next.  It doesn’t bother me, I’m just glad to see them thinking about FX now.  It looks like they have moved (thinking) in the direction that I was hopping for.  

KMS