need a litte help with mxr noise gate clone

Started by whomeno, October 05, 2018, 08:41:03 PM

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whomeno

built the noise gate clone from here
http://tagboardeffects.blogspot.com/2013/01/mxr-noise-gate.html
it is the stock version
Bypass works
Nothing when turned on
I used 2n3904 for q 1 and 2
q3 is 2n5485
Change 680R to 4.7k
The 1M that's going from JFET Gate to 1.8k













voltages    power 8.74

4558
1  4.83
2  4.22
3 1.50  to 3.0
4  0
5  2.90
6  4.32
7  4.32
8  8.74

q1
e  0
b  0
c  4.77

q2
e  3.92
b  3.14
c  8.74

q3
d  .40
s  4.80
g  4.80
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

Slowpoke101

You have the transistor that is close to the centre of the board installed backwards.
Reverse it and redo your voltage measurements.
Be aware that these noise gates can be a pain to get to work.
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whomeno

i caught that  when doing the volages. rechecked votages and listed them
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

Slowpoke101

Good.
Now check your 100K resistors. The colour code is a bit difficult to see but they look like 100R (brown, black, brown, gold not brown, black, yellow, gold - 5% resistors).
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whomeno

you are right.... I just ordered 100k and they sent me 100r... I will check them from now on.will change them and take new readings
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

whomeno

#5
trannys are loose in sockets goin to solder straight to board
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

whomeno

4558
1  8.1
2  4.2
3  4.7
4  0
5  2.8
6  4.2
7  4.2
8  8.7

q1`
e  0
b  0.3
c  4.3

q2
e  3.2
b  0
c  4.7

q3
d  1.7
s  4.7
g  4.4
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

Slowpoke101

Progress.
Now pin 1 of the IC should be about 4.5V and not 8.1V so check for any shorts to that track.
The base of Q2 is very low. It's fed by a 470K resistor that is tied to the 4.5V rail. Check to see if that track has any unwanted shorts or solder bridges to other tracks.
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whomeno

#8
pin 1   4.85
q2
e  8.74
b  3.13
c  3.91

q1
e   0
b  .46
c  4.73

q3
d  3.20
s  4.70
g  4.69
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

Slowpoke101

OK. Pin 1 looks much better. However Q2 is really off now.
Please tell me that you transposed the Collector and Emitter voltages.
If you have done so then everything is looking good and you can try to see if it works.
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whomeno

#10
it seems to be working now. the 1k at the input was down 1 hole. put it where it needed to be and it seems to work.
How much noise should it take out never used one before?
when i switch it on I can tell the volume drops a very little.
But to me when I turn the sens up and down it don't seem to make a differance
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

Slowpoke101

It should mute any signal going into it that is lower than the level set by the sensitivity pot. Any signal higher than that level should pass through with little to no attenuation at all.
Set your guitar to max volume and select the bridge pickup. Adjust sensitivity to minimum. Then lightly run a finger up and down the low E string (6th string) and see if you can hear that noise. If not, turn the sensitivity pot all the way up and try again. If you now hear the noise, adjust the sensitivity pot slowly back the other direction until you don't hear the noise.
Now play something - the gate will mute when you are not playing and will mute when you stop.
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whomeno

ok will have to give it a try after i get up. Thanks for all the help. going to try the boss ce-3 next. waiting for parts .
might get started on the mxr blue box.
Thanks again
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals