13700 Noisegate/Expander

[deadastronaut]

Is it not...

ill defo be breading this when i have a spare board...pretty good gate.

[Kipper4]

I was doing alright until i got to componant c3 and realised i dont have any 3u3 caps
Question Will any 3.9v zener do or does it have to be this model. I'm fresh out of these too. (Never actually had any)
Q2 does the zener wattage matter?
The good news is I've started my build.
Thanks guys

[armdnrdy]

For C3...you can tack three 1µf caps in parallel until you get your hands on a 3.3µf.

Any 3.9 zener will work. Wattage doesn't matter.

[Kipper4]

Cheers Larry

[knutolai]

sweet gate! Nice demovideo. What would be the maximum peak-to-peak voltage through the LM13700 in this application? I've heard they will distort easily if handling a hot signal. Is this a limitation to this design?

[Kipper4]

I'm about 1/3 of the way through my build.
Just waiting on some zeners to arrive. I bought these i hope they work out ok

http://www.ebay.co.uk/itm/20x-Zener-Diode-BZX55C-0-8V-to-30V-0-5W-FAST-DELIVERY-/160784709135?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item256f83f60f

[Kipper4]

I'm doing well here!!!!!!!!!!
no TL061's in stock
I guess I can just sub it with an LM741 right?

[DIMstompboxes]

I'm doing well here!!!!!!!!!!
no TL061's in stock
I guess I can just sub it with an LM741 right?

Yes same pin assignment.
IIRC, TL061 is a JFET opamp and LM741 is not. Try to use it for a moment maybe its OKEY.
One report stated he used only half of bipolar 4558 of course with his own design PCB orientation.
Forgot to asked him how's the performance, coz I used JFET.
   

[Kipper4]

Thanks DIM
if my zeners get here tommorow I'll give it a shot
the boards ready for testing now. All off board wiring done.

Some hints and tips on what the trimmers do and how to set them up would be helpful too please guys.

Rich

[DIMstompboxes]

Thanks DIM
if my zeners get here tommorow I'll give it a shot
the boards ready for testing now. All off board wiring done.

Some hints and tips on what the trimmers do and how to set them up would be helpful too please guys.

Rich

Hi Rich,
Calibrate those trimmer with expander ON and Bypass OFF. Just make sure its one to one unity, no other gadget involve only your clean(without noise)guitar/expander/amp.
TR1 (2K)trimmer for the OTA inputs you just adjust the setting where the clean guitar high string(single) ring out naturally. ON and OFF.
TR2 (5K)is for LEVEL volume adjustment also with clean guitar(single or multi string) ON and OFF set it same in VOLUME level. Mine I put it in the outside so I can adjust when louder live situation is needed.
Unfortunately I never did tried Larry suggestion to make it 10k or even higher just experiment maybe it's better.

Cheers,
Roger

[Kipper4]

Nice one Roger.
Now I think I know where I'm heading.
I guess the expander on is with the switch letting the resistor disconnected and not going to ground right?
Thanks for the help.
I must have missed Larry's post about the 10k trimmer.
I may well do the external pot like you too.

[DIMstompboxes]

I guess the expander on is with the switch letting the resistor disconnected and not going to ground right?

Correct. you can even discard the 47k resistor if you want permanently the expander is ON. (as downward expander noisegate)
IF you want it to NORMAL you need the 47k plus the SPDT switch connected to the ground so the expander is OFF.
IIRC when the expander is OFF and set to NORMAL it is MUTED or as in bypassing the circuit I can't recall.
Mine is always exp ON and no switch. I like to clear up this also with Larry.
Let me just add on CALIBRATION procedure, what I meant by expander ON/Bypass OFF is the DPDT or 3PDT footswitch to engage the effect. Mine is DPDT with millennium bypass and LED indicator.
Do the calibration on those trimmer with just clean guitar on both effect ON and Bypass OFF not with that SPDT and make sure the sound is the same (unity) when ON or OFF.
After calibration, test it with your HIGHGAIN or DIRT box with single coil or just make an awful noise or hum then let us know.   

Oh about the 10k trimmer was just a question also by Larry if this can be made or replace with. You can experiment buddy and tell us also about the SPDT when it is set to NORMAL.
Cheers,
Roger  

[Kipper4]

Thanks for clearing that up for me as soon as I get back from my visit to the grand kids today. I'm hoping the Zener diode will arrive so I can mess with this.
Cheers
Rich

[Kipper4]

How about the tl071 or tl081
From what I've read they may make a better replacement for the tl061
At least they're both jfet based
Whatcha think?

[armdnrdy]

Either one will do.

[Kipper4]

Cheers Larry
Tl071. X3 on order

[Kipper4]

its hooked up
i checked most of my nodes with the DMM
switch off adjusted the tr1 trimmer result zilch

my voltages seem wrong to me

Q1
c 9.19
b3.17
e9.19

Q2
c9.19
b4.46
e3.90

Q3
c9.18
b9.12
e0

Q4
c9.19
b8.98
e0


ic1   tl071
1 0.13
2 1.42
3 1.08
4 0
5 0.13
6 1.43
7 9.19
8 0

ic2 lm13700
1 0.13
2 1.05
3 4.66
4 6.7
5 4.48
6 0
7 0
8 0
9 0
10 0
11 9.19
12 0.2
13 0.2
14 4.6
15 0.02
16  0

those transistors voltages look all wrong to me
suggestions please
otherwise i'll start a debugg thread tommorow
thanks guys

[Kipper4]

latest report i found a resistor end i forgot to clip off
it passes signal intermediatly now so i reckon i have some bad connections or bridges

[DIMstompboxes]

Rich, take your time buddy...

[Kipper4]

I will buddy as soon as I get time I will put the DMM back on it and probe it too.
I briefly probed the input and found no signal on the q1 emitter .
Thanks for the encouragement DIM.
I'll get it sorted.
At the moment it's just gating to much when it does pass signal.
Btw I hadn't realised that d5 was an external led I put a red diffused 5mm led right there on the board. Doh
Later guys it's time for bed
Thanks