Tonepad MXR Noise Gate to 'smart' gate

Started by FunkyGibbon, June 03, 2009, 09:46:20 PM

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.Mike

Here are the voltages from my working unit.

Battery= 9.69
Battery when connected to effect= 9.60
Threshold= Full Clockwise

Q1
C= 9.60
B= 3.18
E= 4.02

Q2
C= 3.80
B= 0.42
E= 0

Q3
D= 4.84
G= 2.89
S= 4.84

U1 - UA741CP (IC1a on Tonepad schematic)
P1= 0
P2= 4.42
P3= 4.83
P4= 0
P5= 0
P6= 4.89
P7= 9.60
P8= 0

U2 - UA741CP (IC1b on Tonepad schematic)
P1= 0
P2= 4.76
P3= 3.17
P4= 0
P5= 0
P6= 4.77
P7= 9.60
P8= 0

D1 (not on Tonepad schematic, polarity protection)
A= 0
K= 9.60

Z1 (zener)
A= 0
K= 4.83
If you're not doing it for yourself, it's not DIY. ;)

My effects site: Just one more build... | My website: America's Debate.

El Heisenberg

#21
Here are the readings from my modified build

with the threshold on max

battery: 8.95
vb= 4.03

Q1
C= 8.85
B= 2.68
E= 3.32

Q2
C= 3.22
B= 0.35
E= 0

Q3
D= 4.03
S= 4.03
G= 3.21

IC1
1= 4.03
2= 4.03
3= 4.03
4= 0
5= 2.94
6= 4.42
7= 4.42
8= 8.85

pretty close to the commercial unit eh? Cept a little difference on the FET. My circuit is altered tho.


"Your meth is good, Jesse. As good as mine."

El Heisenberg

Forgot to mention with the alterations i did, that i needed to match the bipolar transistors. It dowsnt matter what hfe, as long as theyre both the same, youll get smooth decay.
"Your meth is good, Jesse. As good as mine."

MikeH

Yeah- I'll never make this thing work.  My voltages are pretty much right in between the 2 sets posted here.  I tried some of the posted fixes, and the damn thing still doesn't work for crap.  I think I going to try a DOD230 instead.
"Sounds like a Fab Metal to me." -DougH

solderman

Quote from: MikeH on September 02, 2009, 10:43:13 AM
Yeah- I'll never make this thing work.  My voltages are pretty much right in between the 2 sets posted here.  I tried some of the posted fixes, and the damn thing still doesn't work for crap.  I think I going to try a DOD230 instead.

Hi
The new MXR Dunlop version, the smart Gate has a led indicating when the gate is closed. Any one who knows how to implement that?

I had a quite a five problems before i got it to work. I used the Ver 2 layout from Tonepad and submitted a build report. Now I am verry hasppy with it.

From my buil report:
I used a 2N5485 and two 2N3904s (had only two) to start with. They where quite far apart (240 265) in hFE, witch resulted in a "choppy" decay. Changed to two 2N5088 with 462 and 465 hFE and I had a smooth decay when the gate kicked in. So I found the same thing as Brett, hFE value does not matter as long as they are matched.

- To get a god level for release I tested a lot of different values for Ra. 2M2 worked best for me.


Summary; A very worth while build but not if you are a total beginner or if you lack patience. A tip is to use sockets for the trannis and the Ra and 680R restitor/1mF cap. When you test/tweek it do it with the load of the guitar PU and dist boxes etc you think you will use it with. At the end of the day the most useful situation for this box might be to use it to gate hizz from heavy distortion on high volume in a live setup.

The only bad sounding stomp box is an unbuilt stomp box. ;-)
//Take Care and build with passion

www.soldersound.com
xSolderman@soldersound.com (exlude x to mail)

jatintalwar

Mine refuses to work by all means !!!
2N 3904 and 2N5952 with correct orientation
Just normal sound before 50% Threshold and Clicking distorted sound after that ..
Tried all the trouble shoots given above but none seems to work :
1) Changed the input RC network to 4.7 K resistor and 2.2mfd ... No success
2)Changed the Resistor connnecting gate to R a to 1.5 K ....No success
3) Changed the orientation of 10mfd connecting to drain of fet
Voltages : ( with threshold pot all the way to 100% clockwise
Vcc : 9:01 V
Vb
Q1
E
B
C

Q2
E
B
C

Q3
E
B
C

IC
1
2
3
4
5
6
7
8