1 Knob Noise Gate

[boratto]

[Silver Blues]

What?  Does this actually work well?

[boratto]

It´s not verified yet... will be great to fit on double effect boxes.

[Muadzin]

What sort of diodes go into this thing? Also, I take it the BC549's are BC549C's? Or could I use BC549B's?

[boratto]

Original schematic BC109, so i think you can go with a modern one (cheaper), any BC549, will do the job.
Diodes 1n4148.

[Synsound]

I built this one with a BS170 and BC109's. It didn't do anything but cut total volume by 90%. I couldn't tell if the pot was making any difference.
I don't have the knowledge to trouble shoot but thought I would post my results.

[Chris60601]

This looks to be the schematic.

[Synsound]

I'll give it another look in the morning to see if I screwed up in the build.

[boratto]

I found capacitor 1uf should be connected to base of Q1, and not the collector as in the vero. I´´ll update soon.

[boratto]

Syn, the vero is now updated, 1uf must connect 2m2 resistor and base of Q1.

[Synsound]

You can call it verified. I made your correction and added the 1u in the middle that I overlooked.
The only change I made was to use a B50K pot. The 1M was way overkill IMO. I found that I was able to kill a high gain his at about 15K resistance so this still gave plenty of room to spare while not having to fight so hard to find the sweet spot. It prob would be good at 25K. I may adjust more later if I find it the need.

Thank you for the layout.

[Silver Blues]

So it's good then?

[Chris60601]

May I make a suggestion please?

Move the jumper between 100u and 1u to just right of the collector of Q1 and left of 1u
Slide the rest of the layout to the left by one

Move 22n left one space
Move D1 (by base of Q2) to the left one space along with the jumper that was below it
Slide everything even with Q2 to the left 1 space.

This should free up a few columns by 2 I think - have a look.

Cheers
Chris

[Synsound]

Yes it is good

[boratto]

Thank you gus, smaller is best, always! Syn drop a line when you test.

[Synsound]

Silver,
You mentioned your buddy was wanting a noise gate. I would opt for this over the MXR.

[boratto]

Thanks Syn, would a reverse log, or log a better sweep?

[Muadzin]

I've noticed that in the layout Chris did C4 (10uf) spans 2 rows and C3 (1uf) spans 3 rows. In the updated boratto layout at the top 10uf spans 3 rows however and the center 1uf 2 rows. The exact reverse.

So which is correct?

[Chris60601]

Ah - good catch. My mistake. I'll correct later when I'm home.
Sorry about the oversight.

Cheers
Chris

EDIT: Here is the fixed version.

[Synsound]

 A log or rev log pot may help out. I'm not the most educated fellow on such matters. The the sweet spot seems to be about 1/3 into the sweep assuming you are starting at 7:00 going clockwise. I'm not sure which taper would compliment that.
Again I did  my testing with pretty heavy hiss from a  Pharaoh on high gain with a Rocket Animal pushing it (also set high)