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DIY Stompboxes => Building your own stompbox => Topic started by: armdnrdy on December 12, 2013, 11:58:57 AM

Title: 13700 Noisegate/Expander
Post by: armdnrdy on December 12, 2013, 11:58:57 AM
There were a couple requests to retrofit a LM13700 into a noise gate/ expander board that originally called for a CA3080.

This is one of the projects that appeared in a Japanese effects book from the 80s. These files have been available on Mark Hammer's site (Ampage) as well as a few other places on the net.

I kept the board layout close to the original, but added a few things. Among the things that were added were input/output pull down resistors, a resistor tied to V+ and pad for effect engaged LED, and a few extra ground pads. Also, the original 2SC1222 and 2SA640 transistors were changed to BC550 and BC560.

There were a few discrepancies between the original schematic and original board routing/layout. These were mainly component positions switched. (C10<>R14, C8<>R12, C6<>R8) The redrawn schematic reflects the original board layout.

As noted above, there is a pad for an effect engaged LED. This would be the pad in the upper right corner marked "LED".
There is an additional LED marked "D5". This should be a gating indicator, and should turn on and off with the gating.

It is my thought that some experimenting can be done with this circuit. The Expand/Normal switch (SW1) can possibly be changed to a 50K pot. (with an additional resistor to ground?)

TR2 can be changed to a 5 or 10K pot? Level control?

Just some things I'm throwing out for the mod minded.

Here's the project file PDF:

https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Noisegate-Expander%20file.pdf (https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Noisegate-Expander%20file.pdf)

(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Noisegate-Expander%20overlay.jpg)






Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 12, 2013, 12:04:34 PM
Excellant Larry thanks so much.
Another one for the list.
Title: Re: 13700 Noisegate/Expander
Post by: Mark Hammer on December 12, 2013, 12:21:08 PM
Now THAT's citizenship!

Many thanks.
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 12, 2013, 12:28:31 PM
Now THAT's citizenship!

Many thanks.

I wanted to take a break from all of the flanger madness and work on something easy!

I don't even want/need a noise gate!  :icon_wink:

Title: Re: 13700 Noisegate/Expander
Post by: Fender3D on December 12, 2013, 01:05:34 PM
I wanted to take a break from all of the flanger madness and work on something easy!

You traitor...
 :icon_mrgreen:

Why don't use IC's buffers instead of Q1 and Q2?
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 12, 2013, 01:12:49 PM
I thought about it but I would have to mess with some of the other components (darlington versus single tranny) and my bread board is full with the Tyco flanger pedal circuit.

If someone wants to play with it....I'll redo the board.

I'm not a traitor...I just needed a break! I started hearing flanging in my sleep!  :icon_eek:
Title: Re: 13700 Noisegate/Expander
Post by: deadastronaut on December 12, 2013, 01:16:38 PM
I started hearing flanging in my sleep!  :icon_eek:

that's mad, i remember when i first got a phaser when i was 14, i used it so much that i swear i could hear phasing in everyday life...cars..people talking...etc...very weird feeling.


hows the gate on this..abrupt?..smooth fade?..
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 12, 2013, 01:24:36 PM
I haven't built this.
The first request to retro the board came from the forum member DIMstompboxes who built one with the original 3080.
Maybe he'll pop in and describe the gating.

I'm just a bystander in this one...not really of the innocent type though.  :icon_wink:
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 13, 2013, 06:36:10 AM
Great new layout armdnry, Any PNP or NPN can be use and you'll not regret after you built this one. Three of us has verified DimebuGG, Kmr and included me you can PM them and they are members here.
But Note, we all used both TL061 and CA3080. This will surely kick out the MXR fet noisgate with lot of lots of  issues.  :) 
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 13, 2013, 12:18:40 PM
I forgot to include in the BOM......the footprint for the trimmers is a Bourns 3362P.

A copy of the Bourns trimmer can be found at Tayda.

http://www.taydaelectronics.com/potentiometer-variable-resistors/cermet-potentiometers/3362p.html
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 13, 2013, 07:52:59 PM
TR2 is just for level control I used 5k outside knob for it and the other knob is for sensitivity A 1M knob. That TR1 is 2k trimpot for balancing.  :)
Cheers,
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 13, 2013, 08:18:04 PM
Thanks for the info.

What did you do for the Expand/Normal switch? I don't see a switch on your build.

It looks like gate LED, Effect LED, bypass switch, and the two controls you outlined.


(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/ExpanerandNS2noisegate.jpg)
Title: Re: 13700 Noisegate/Expander
Post by: slacker775 on December 13, 2013, 11:18:45 PM
Anyone have Eagle files for this or have it shared on Oshpark?  I've had an odd interest in building a Noise gate for bit.
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 13, 2013, 11:24:48 PM
Eagle schematic file:
https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Noise%20Gate-Expander.sch

Board file:
https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Noise%20Gate-Expander.brd
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 13, 2013, 11:43:06 PM
Thanks for the info.

What did you do for the Expand/Normal switch? I don't see a switch on your build.

It looks like gate LED, Effect LED, bypass switch, and the two controls you outlined.


(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/ExpanerandNS2noisegate.jpg)

Just connected it to the ground for NORM and use the sensitivity control knob, EXP seems too fast for gating and release and little bit compress but you can add that mod just lazy to drill another hole. You'll not regret it, there is no stuttering note alike the MXR I built and sustain as a good decay.   
Title: Re: 13700 Noisegate/Expander
Post by: deadastronaut on December 14, 2013, 10:37:41 AM
Cool...be nice in a 1590b..
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 14, 2013, 01:19:38 PM
How. Critical are the transistors?
And are they replaceable with something that I have in stock like a 2n5088, 2n5089, bc109 although the gain might be a little low on the bc109.
Are the bc550 , 560s a common reasonably priced model.
Just asking
Thanks
Rich
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 14, 2013, 02:07:27 PM
How. Critical are the transistors?
And are they replaceable with something that I have in stock like a 2n5088, 2n5089, bc109 although the gain might be a little low on the bc109.
Are the bc550 , 560s a common reasonably priced model.
Just asking
Thanks
Rich

I switched the Japanese transistors to what I thought would be more easily sourced transistors for you in the U.K.
The BC trannys that I chose are very common. They are even sold at Tayda.

The original NPN (2SC1222) is a low noise amplifier.
I believe that this tranny was used in this design because.....if you were going to use a noise gate....you were probably concerned with noise and didn't want to add to it. Logic 101  :icon_wink:

The PNP transistors are not in the signal path so.......I don't think that they are critical.

By the way...hold the phone on the original board. Due to Rob's (deadastronaut) little nudge, I reworked the board to fit in a smaller enclosure. Thanks Rob! It's not like I don't have enough to do!  ::)
Title: Re: 13700 Noisegate/Expander
Post by: deadastronaut on December 14, 2013, 02:15:44 PM
Ahhhh...good man. Nice one..

 8)

i know you like to keep busy... ;)
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 14, 2013, 04:03:24 PM
For your small box pleasure.

(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Overlay.jpg)


PDF file:

https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Noise%20Gate%20-%20Expander%20build%20PDF.pdf (https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Noise%20Gate%20-%20Expander%20build%20PDF.pdf)
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 14, 2013, 05:46:57 PM
I did a bit of searching and bought those trannys.
really reasonably priced thanks.
So this is on my xmas build list.
What you have done has not gone unnoticed Larry we all appreciate your work.
Its about time some decent diy noise gates came up.
I have most of the bits to build the maxon too.
Something tells me im gonna have a noise gate run on soon.
Thanks again Larry your one in a million.
and to DIMstompboxs too and Rob
Title: Re: 13700 Noisegate/Expander
Post by: deadastronaut on December 14, 2013, 05:53:33 PM
nice one larry.. 8) 8) 8)

still got my head in my 4pt delay cooking at the mo, but this will be on my 'just build it '' list after xmas.

anyone done a demo of it yet?...
Title: Re: 13700 Noisegate/Expander
Post by: pinkjimiphoton on December 14, 2013, 07:22:36 PM
I started hearing flanging in my sleep!  :icon_eek:

that's mad, i remember when i first got a phaser when i was 14, i used it so much that i swear i could hear phasing in everyday life...cars..people talking...etc...very weird feeling.



i think i did some of that acid too   :icon_mrgreen:

Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 20, 2013, 07:10:45 PM
Guys,
Yes it's verified with TL061 and CA3080 and using NPN 2n5088 PNP 2n3906 with Zener 1n5228.
BTW you can also use 100K log for better threshold just experiment.
Sorry for the delay i'm so busy  I benchmarked all with the same set up with my TScreamer and AMP. First on the FRONT using single coil guitar-noisegate-TS-AMP. TS set to full drive and AMP loud enough to hear the noise. Result.: Expander- just minimum threshold good fade at the end no trailing noise, guitar sound one is to one when on and off
Boss- full threshold with minimum or considerable stuttering or trailing noise, guitar sound one is to one when on or off
Mxr clone- 95% threshold with no stuttering but lost in volume, guitar sound not one is to one when on and off.
Now I put the noisegates at the BACK chain Guitar-TS-noisegate-AMP.
Result: Expander - max or full in threshold with minimum stuttering when fading but very considerable.
Boss - full threshold loud hum can not tame the noise defintely failed in test it is only good at the FRONT of the chain.
Mxr clone - full threshold hum still audible but not louder than Boss, guitar sound fairly low. THAT IS WHY I DITCH OUT my MXR and use the casing for other project :)

My Rating
Mxr 80% due to volume lost
Boss 85% good on FRONT
Expander 95% but not 100% or perfect.

Cheers,
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 20, 2013, 07:35:38 PM
you mean to say you didnt make the lm13700 one DIMstompboxes?
That was kinda the point of this thread and the reason larry did all the graft.
I'm waiting on supplies when i get some chips i'll do it over christmas.

However i'm pleased you like it and rate it better than the others.
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 20, 2013, 07:40:26 PM
I think this review is from a previous build of the noise gate/expander from the Japanese stomp box PDF.

Not from the version that I posted.
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 20, 2013, 08:04:40 PM
Gottya I beg your pardon
Title: Re: 13700 Noisegate/Expander
Post by: knutolai on December 21, 2013, 11:46:53 AM
Something I thought of when looking at the circuit (nice work btw!):
Could this be build as a wrap-around for a noisy effect pedal, say something with a constant oscillator bleed like a Ring Modulator, to fade away unwanted noise when nothing is being played? I'm mean I know that's what a noise gate do, but would it optimize the noise suppression if one placed the noisy pedal at the C3 point instead of in front of the whole expander circuit?
This way the noise generated from the pedal won't affect the amount of attenuation. Hope I'm making sense  :icon_smile:
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 21, 2013, 12:22:31 PM
Could this be build as a wrap-around for a noisy effect pedal, say something with a constant oscillator bleed like a Ring Modulator, to fade away unwanted noise when nothing is being played?

If you have a breadboard, you can experiment with a simpler circuit. You can "tweek" components until it's working correctly for your circuit.

Here's a circuit you can try:

(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/noisgate%20resized.jpg)
Title: Re: 13700 Noisegate/Expander
Post by: bean on December 21, 2013, 08:13:41 PM
Really interested in building this. I decided to have a go at a layout using the unused buffers in place of Q1 and Q2. Here is the re-draw.

edit: check pdf project file below for schematic re-draw

And the layout:

(http://www.madbeanpedals.com/misc/Gate_Exp_Layout.png)

If anyone wants to have a look at the my schem and confirm it I'm happy to post the PCB artwork, so long it is okay with armdnrdy.
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 21, 2013, 09:17:19 PM
Post away Brian!

I'm just curious if the first darlington buffer will "blast" too much current into the non inverting input of IC2 (061) and the inverting input of IC1. (13700)

Might have to adjust R4 for the increased HFE.

The other buffer is after T2 which can be adjusted for level, but if anyone wants to replace T2 with a pot for a level control....might cause issues.

or.....am I completely wrong?
Title: Re: 13700 Noisegate/Expander
Post by: bean on December 22, 2013, 05:41:53 AM
Here is the project file. I named it "Fencepost" since Gate_Expander is...well, descriptive but not fun.

Eagle files/pdf/BOM all in the zip.

http://www.madbeanpedals.com/projects/Fencepost/Fencepost.zip (http://www.madbeanpedals.com/projects/Fencepost/Fencepost.zip)
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 22, 2013, 01:54:18 PM
Did you build it yet Bean.
I'm anxious to hear how it works.
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 22, 2013, 02:10:50 PM
I'm a bit curious as to the effect of darlington pairs in place of single NPN transistors in this circuit.

Darlingtons have twice the base emitter voltage drop when saturated.

Can someone pop in and give some input?

It would be helpful in implementing LM13700s in other circuits.

Here's Brians redraw with the two darlingtons replacing single NPNs. The darlington collectors are connected to VC internally inside of the 13700.

(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/Fencepost.jpg)



Title: Re: 13700 Noisegate/Expander
Post by: bean on December 22, 2013, 02:20:46 PM
Would increasing R3 to 1M or 1M5 mitigate that somewhat?
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 23, 2013, 01:32:53 AM
you mean to say you didnt make the lm13700 one DIMstompboxes?
That was kinda the point of this thread and the reason larry did all the graft.
I'm waiting on supplies when i get some chips i'll do it over christmas.

However i'm pleased you like it and rate it better than the others.

Not to confused or any malicious intent, my previous username here was rogeryu_ph which I also using it on FSB so I elected to change it here with a new DIMstompboxes which mean Do-It-Myself stompboxes not DIYstompboxes and thats the only reason.
I posted my breadboard report here way back 2008 on Downward Expander Noisegate
here http://www.diystompboxes.com/smfforum/index.php?topic=66277.0 (http://www.diystompboxes.com/smfforum/index.php?topic=66277.0)

Presently on my analog set up I only just using the Downward Expander noisegate and the NS2 is redundant so I keep it only for future back up. I'm also using Digital set up with my Boss GT10 in some venue when direct to mixing desk.
Also the reason why I delete my Youtube video report that time was to prevent and NOT to compete with Tonepad MXR noisegate and I highly regard Francisco for his works.
Lately I chime in on this armdnrdy's thread and share somehow he might use and design LM13700 OTA as replacement for CA3080.
That's the whole story just to payback and share what I learned to this great forum.
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 23, 2013, 01:44:30 AM
Here is the project file. I named it "Fencepost" since Gate_Expander is...well, descriptive but not fun.

Eagle files/pdf/BOM all in the zip.

http://www.madbeanpedals.com/projects/Fencepost/Fencepost.zip (http://www.madbeanpedals.com/projects/Fencepost/Fencepost.zip)

Hat off to you Brian, nice to see you here. I'm a member in your forum aka angelo  :)
Cheers,
Title: Re: 13700 Noisegate/Expander
Post by: PRR on December 23, 2013, 06:26:20 PM
> Darlingtons have twice the base emitter voltage drop when saturated

Saturated? Pretty much all through the Active range.

Do math.

Assume Q1 base sits at 4.5V, then check if that is true.

Single transistor:

If base is at 4.5V then emitter is at 3.9V. It feeds 22K so must flow 3.9V/22= 0.177mA. Any decent jellybean has hFE over 100. So base current is 0.177mA/100= 0.00177mA. This much flow in 510K is 0.00177mA*510K= 0.9V drop.

So first-crack, base actually sits at 4.5V-0.9V= 3.6V, and emitter is near 3.0V. That reduces the flow in the 22K and all throughout. I suspect the drop in the 510K comes to less than 0.8V but more than 0.2V, emitter sits at 3.1V to 3.7V.

Darlington:

Assume base is near 4.5V. Emitter near 4.5V-1.2V= 3.3V. Current in 22K is 0.15mA. Darlington hFE is over 10,000. Base current less than 0.000,015mA. In 510K this is 0.000,015mA*510K= 0.0077V drop, "zero".

So first (and final) crack, base at 4.5V, emitter at 3.3V.

What is the difference between "3.1V to 3.7V" and 3.3V? Hardly-any.

Either way you can get 2V peak for-sure. Since it is hi-Z loaded you can approach 3V.

But (on 'Brians redraw') isn't there a 15K missing near the OTA input? Guitar can run near 500mV. The OTA can only take 20mV-50mV before it goes gross. Usually we take something like 15K:1K voltage divider. There is a 15V on the other side of the OTA input, but not on the signal side input.

The "idle" OTA-- in theory, if you nail Iabc to the negative rail it goes dead. Leaving it open "seems to" do the same, except it tends to pick-up crap. I think if you run 1K from Iabc to V-, you can forget all the other pins on that OTA. Saves 12 cents.
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 23, 2013, 08:02:29 PM
Here's the original breadboard pictures report on my photobucket using CA3080. Fortunately I saved it on my photobucket but unfortunately that time my camera can only save up to 512mb and video can't be saved on photobucket that year(2008) only on Youtube and I erased and never did saved it. Don't let me do the video demo again i'm kind of shy type of guy hahhhhahhha.
Cheers,

(http://i186.photobucket.com/albums/x139/rogeryu_ph/DSC04714.jpg)
(http://i186.photobucket.com/albums/x139/rogeryu_ph/DSC04713.jpg)
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 23, 2013, 08:53:53 PM
Oh btw, this is becoming interested to me  :)
Brian is here lately, PRR is here and still waiting for Mark to chime in once more and also R.G.
I'm eager to pull that CA3080 and use it for Dyna compressor which I already have Ross and planning to build expander noisegate into smaller box with LM13700 which I have 3pcs of it and use
the existing box for bigger project.
I'm not much into math and theory like PRR only I know that pin5 of the CA3080 is the current control plus there is a 2k trimer on the input of the OTA.
Cheers,
Roger
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on December 23, 2013, 11:11:11 PM
So when it's all said and done...and you do the math...the circuit should work about the same with the darlingtons in place of the single transistors.

But (on 'Brians redraw') isn't there a 15K missing near the OTA input? Guitar can run near 500mV. The OTA can only take 20mV-50mV before it goes gross. Usually we take something like 15K:1K voltage divider. There is a 15V on the other side of the OTA input, but not on the signal side input.

I believe that Brian used my redraw for his drawing. Both are as the original circuit, no missing 15K.

The "idle" OTA-- in theory, if you nail Iabc to the negative rail it goes dead. Leaving it open "seems to" do the same, except it tends to pick-up crap. I think if you run 1K from Iabc to V-, you can forget all the other pins on that OTA. Saves 12 cents.

Are you referring to the unused OTA pins?
I followed the advise from a T.I. applications engineer to put the unused device in a known valid operating state.
It was suggested to set the part as a unity gain follower with input at half of supply.




Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 24, 2013, 08:55:56 AM
I think the schematic was this one right?

http://hammer.ampage.org/files/Expander.gif
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 24, 2013, 10:29:08 AM
Is this it PPR

(http://imageshack.us/scaled/modthumb/835/s9vj.jpg)[/URL][/img]
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 24, 2013, 11:02:05 AM
I think the schematic was this one right?

http://hammer.ampage.org/files/Expander.gif

YES that's the schematic and PCB I built from a Japanese genius  ;D
First I breadboard it and file a report here with Youtube demo with couple of mod I made after that I boxed it. Then followed by (kmr) member here also who just used half of the 4558 not TL061.
Then came (DimebuGG) also a memeber here and FSB with his own PCB design. After that no other one who dare to built it and that thread when away so I posted a thread "Tired of MXR fet noisegate use this Downward Expander"
I felt I might get wrong competing with MXR user of Tonepad so I delete that Youtube demo.
I just want to share that there is an alternative noisegate beside NS2 and MXR that I have and this is it. I haven't tried the ISP decimator but I shared this one with Evan at FSB and replied me just thanks. I was hoping only I could compare it with ISP because I can't get THAT2181C chip here.

Here's the couple of mod I just made:
Add a series 1.5v zener after the (470ohms and 4.7k resistor with signal diode) junction and before signal diode with circle T and circle C. The zener should be anode pointing to TR3. This help to smooth threshold gated sound and decay more natural. Depend on your ear just experiment from 1v-4.5v zener.
 
I used A100k Log instead of 1MA for sensitivity. These were just my own radical changes and thinking while it was still on breadboard, just try the stock first and do improvement later then share it buddy.


  

Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 26, 2013, 12:37:38 PM
Heres my perfboard layout
If you see anything wrong feel free to correct me thanks
Rich

sorry its drop box. I tried to post a link but it was so small you couldnt see it. and I figure not everyone has the same version of DIYLC.
At least this way you can import to photoshop (read other image viewers) and enlarge easily.


https://www.dropbox.com/sh/7ma9n53c5jqdgsr/nTW79Toq_J/NOISE%20GATE%20EXPANDER%20LM13700%201.png
Title: Re: 13700 Noisegate/Expander
Post by: bean on December 26, 2013, 03:55:06 PM
Did you build it yet Bean.
I'm anxious to hear how it works.

It will be a while before I can, unfortunately. Although I do very much want to build one.
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 26, 2013, 04:21:09 PM
I realise your a busy man SD. I wasnt pressuring you mate. Just wondering:)
I will probably build it myself in the next week hopefully.



I just want to make sure my layout is ok first. Anyone?
Title: Re: 13700 Noisegate/Expander
Post by: deadastronaut on December 26, 2013, 05:14:36 PM
hi rich, its a bit on the large side..

no chance of a 1590b with it. :)
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 26, 2013, 05:35:17 PM
Good point. Thanks Rob.
I'll condense it when i know its a goer. Meh :(

I'll rework it
thanks mate
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 26, 2013, 06:06:41 PM
Oh I browse with my messages on FSB it was FrankWhite not Evan that I shared. If you know the guy.
BTW,  I don't have 1MA log before that year that is why I used 100KA log. Just try the stock first.

Cheers,
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 26, 2013, 08:00:41 PM
I done a simple demo it's a holiday, using SINGLE COIL (center) with TS( drive) just to increase hum with OPEN STRING fair to just give you an idea. We all generally know that the strat single coil reputable for its annoying hum :)
Again, I will delete this sometime next year January for I don't want anybody to get me wrong especially the Boss community. Also this is not a comparison just sharing you it works. Strangely the youtube decreases the hum (for better quality playback I think) or I don't know why just use your headphone for better monitoring.

 

Cheers,
Title: Re: 13700 Noisegate/Expander
Post by: Mark Hammer on December 27, 2013, 05:35:25 PM
That's a very favorable comparison, I have to say, and a strong recommendation for making the expander.

I still tend to recommend building an SSM2166-based compressor, since it includes downward expansion onboard (and does a great job of it), but I suppose there can be circumstances where one wants the expansion without the compression, or vice versa.  Mind you, given the manner in which the downward expansion is adjusted, it is probably feasible to use a SPST (or DPDT, since one likely wants LED indication) to enable/disable the expansion function.  You can also switch back and forth from a minimum to preset maximum-compression with a similar footswitch, but the complication is that more compression comes with higher output level, so it is tricky to easily alternate between negligible compression (largely equivalent to bypass) and noticeable compression while maintaining the same average volume level.
Title: Re: 13700 Noisegate/Expander
Post by: deadastronaut on December 27, 2013, 06:00:08 PM
+1 works really well.. 8)
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 27, 2013, 06:00:50 PM
Thanks for the comparaison video.
That works a treat doesnt it.
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 27, 2013, 07:26:35 PM
That's a very favorable comparison, I have to say, and a strong recommendation for making the expander.

I still tend to recommend building an SSM2166-based compressor, since it includes downward expansion onboard (and does a great job of it), but I suppose there can be circumstances where one wants the expansion without the compression, or vice versa.  Mind you, given the manner in which the downward expansion is adjusted, it is probably feasible to use a SPST (or DPDT, since one likely wants LED indication) to enable/disable the expansion function.  You can also switch back and forth from a minimum to preset maximum-compression with a similar footswitch, but the complication is that more compression comes with higher output level, so it is tricky to easily alternate between negligible compression (largely equivalent to bypass) and noticeable compression while maintaining the same average volume level.

It's a NO HOLDS BARRED and I let it just ring out to let you hear how it clamp and decay.
Yes, there is a exp/norm so I opted to normal and lazy to drill for another hold.
BTW, for smaller version box this is okey but what i'm trying to achieved before for bigger box is to have a send/return. Some may use this LOOP SEND unto their drive/highgain pedals then RETURN it to expander to isolate those dirt box then connect OUTPUT unto their modulation pedals (delay/reverb) so the modulation can't be affected.
Wish merlinb of ET would chime in also to do some wizardry and help this project to get this smarter as smartgate  :)
Community lets all in.
Cheerio,
Thanks Rob and Kipper4
Title: Re: 13700 Noisegate/Expander
Post by: knutolai on December 28, 2013, 07:22:32 PM
Quote
what i'm trying to achieved before for bigger box is to have a send/return. Some may use this LOOP SEND unto their drive/highgain pedals then RETURN it to expander to isolate those dirt box then connect OUTPUT unto their modulation pedals (delay/reverb) so the modulation can't be affected.
I could see that being a very useful feature! Was really what I was trying to suggest in my other post.  :icon_redface:
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 29, 2013, 12:35:16 AM
Yes mate,
This is an added feature plus if somebody or merlinb could make this a basic compressor/noisegate with two footswitch. One for clean guitar compressor and the other footswitch to disengaged the compressor and engage the noisegate for the dirt box would be GREAT. Meantime, let us focus on noisegate with the LM13700 first then later with the LOOP feature.
BTW the Downward Expander noisegate perform much better in the front of the chain so its feasible for compressor/noisegate project.
I'm still waiting for both armdnrdy and brian's progress on this, maybe too much busy....
Also I forgot to thank you Mark  :)
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on December 30, 2013, 04:33:24 AM
Just to demo how it gate the hum background with DRIVE on a single coil and still no coloring of the sound. Again use headphone for better monitoring.



Happy New Year
Title: Re: 13700 Noisegate/Expander
Post by: Mark Hammer on December 30, 2013, 09:14:19 AM
Silence is golden, innit?  :icon_smile:
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on December 30, 2013, 11:25:14 AM
Innit.
Title: Re: 13700 Noisegate/Expander
Post by: deadastronaut on December 30, 2013, 08:02:06 PM
Is it not...

ill defo be breading this when i have a spare board...pretty good gate. 8)
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 01, 2014, 03:44:37 PM
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
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on January 01, 2014, 04:20:11 PM
For C3...you can tack three 1f caps in parallel until you get your hands on a 3.3f.

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



Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 01, 2014, 04:47:39 PM
Cheers Larry
Title: Re: 13700 Noisegate/Expander
Post by: knutolai on January 01, 2014, 05:53:23 PM
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?
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 03, 2014, 11:06:19 AM
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
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 03, 2014, 02:55:53 PM
I'm doing well here!!!!!!!!!!
no TL061's in stock
I guess I can just sub it with an LM741 right?
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on January 03, 2014, 05:48:47 PM
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.
    
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 03, 2014, 06:01:50 PM
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
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on January 03, 2014, 06:36:21 PM
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
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 03, 2014, 06:48:15 PM
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.
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on January 04, 2014, 02:31:31 AM

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  
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 04, 2014, 03:45:18 AM
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
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 04, 2014, 11:58:25 AM
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?
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on January 04, 2014, 12:15:18 PM
Either one will do.
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 04, 2014, 12:31:06 PM
Cheers Larry
Tl071. X3 on order
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 06, 2014, 03:04:13 PM
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
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 06, 2014, 03:18:34 PM
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
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on January 06, 2014, 05:05:23 PM
Rich, take your time buddy...
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 06, 2014, 05:17:12 PM
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
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on January 06, 2014, 05:27:34 PM
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

Be back on breakfast... I have kipper for ya :)
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 06, 2014, 05:36:02 PM
Mmmmm kippers ;)
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 07, 2014, 10:57:36 AM
Guys after a couple of hours debugging its working
it turns out i missed off the node from R4 to TR1 lug 1
i'm using TL071 so thats confirmed as well
It's a beauty. I will mess with it later I got stuff to do now but i'll report back when i have it going better.
Thanks to Larry Dim and everyone who made this possible
great work guys
Rich
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on January 07, 2014, 06:01:54 PM
Downward expander perform much better at the front chain...put all your dirt box after it.  Guitar--> tuner/wah -->expander noisegate -->dirt boxes -->modulation effect(delay/reverb)-->AMP
CONGRATULATION
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on January 07, 2014, 06:13:00 PM
Thanks dude
Are all those effects in the chain mandatory?  :icon_lol:


Onwards and upwards.
I have a Deacy amp, treble boost, direct record to rewire first and the maxon noise gate to debugg first.
Then it's play time with the expander
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on January 07, 2014, 09:42:48 PM
Thanks dude
Are all those effects in the chain mandatory?  :icon_lol:


Onwards and upwards.
I have a Deacy amp, treble boost, direct record to rewire first and the maxon noise gate to debugg first.
Then it's play time with the expander


Nope... just as an example.
Great you have maxon noisegate to compare with.
You see many have no thought of reward using a noise gate at all, (nah I don't need one...all my built were ok..) In my experience, this come handy when you move your set up with different amp (not yours) most especially also in various VENUE. Expect the worst  :icon_wink:
Cheerio,
Roger
 
Title: Re: 13700 Noisegate/Expander
Post by: fendman on February 02, 2014, 02:44:22 PM
I also built the noise gate/expander...Luckily I tested the boards' ic and transistor sockets without the components in them   as I had a dead short across the 9v rail :icon_redface: I was also using my bench power supply which has a current limit circuit, so when that red led lit up yeh I thought Hmmm not good!!!

Anyway sorted that out the following morning and tested it on a couple of noisy fuzz pedals, I have used the TLO71, BC349C, and the rest as is the BOM.
The gating and threshold seem to work ok,  this guy has different views about noise gates http://www.ovnilab.com/articles/gate.shtml  

So I will play around with it a bit more. This is the first time I have used a noise gate  so I am still a bit in the dark.
Thanks to the guys on this thread who made it possible

Mike

(http://i.imgur.com/sUup79W.jpg)

Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on February 02, 2014, 06:46:28 PM
Hi mate,
Glad another one brave soul have tried, as I said if you're tired of using FET for noisegate, downward expander is one option.
quote and my thought from your link.
A gate (sometimes called "noise gate") is a downward expander with an extremely high ratio (and abrupt). When your signal level reaches the threshold, a gate goes from "closed" (no signal passes through) to "open" (all of your signal passes through). The threshold where you want to set your signal to be limit (including your noise floor), and above this limit it will open up and signal will passes through.
Threshold also is a common way of controlling noise and hum from high-gain distortions, single-coil pickups, and other noisy circumstances; when you pluck your note, the gate opens, and when the note dies down the gate closes, keeping quiet until the next note.

Tell us more later upon thorough testing your built buddy  :icon_smile:

BTW, this is more effective in the front of the chain before any noisy pedals.
Guitar -> gate -> dirt pedals -> modulation pedals -> amp.
If only someone could add send/return feature on the existing schematic it would be a great so to isolate just the dirt pedals and not affecting the back modulation part somehow.
Guitar -> gate in - gate send -> dirt pedals -> gate return - gate out -> modulation(chorus/delay/reverb etc) - > amp
Anyway mine without this feature is already useful in my analog setup and simple to built and for me I would recommend this compare to FET gate which I also built before. YMMV
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on February 03, 2014, 11:22:10 AM
I also built the noise gate/expander...
The gating and threshold seem to work ok

Mike,

Good to see that somebody built this.....
You have to dial in the controls to where the gating is least noticeable but performs the job it's supposed to do.
the gating should cut in at the end of sustained notes before the noise is noticeable.
You have to find a balance that works for you and your gear.
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on February 03, 2014, 06:10:24 PM
Larry,
Can you try make this to have a send/return feature? I mean this is not just a simple routing.
Mate this is what's on my mind if possible. Using two OTA input and TL072  for
Guitar in  -  DEC send  one OTA input and threshold control
DEC return - Guitar out  one OTA input also with another threshold control knob using the half of the TL072
This way, the user may use the first threshold control knob to adjust the amount for guitar in - DEC send(out) defend on the level amount if you're using noisy pickup e.g Single coil
And the other threshold control knob to adjust the amount of level for DEC return(input) - (to) - Guitar out FOR dirt pedals amount and isolation before going out to modulation stuff.
This is sort of saying DIVIDE and CONQUER idea.
I'm not familiar with Decimator Gstring but this uses only one INTELLIGENT threshold control knob to sense both BUT my idea is manually two knob control for BOTH.
Later design is to make this more SMARTER like including attack/hold/decay control knobs but this is LATER  :icon_smile:

Thanks buddy

   
Title: Re: 13700 Noisegate/Expander
Post by: fendman on February 03, 2014, 08:12:50 PM
Thanks Larry and Dim for your encouragement and help, I spent this afternoon between reading up on noise gates, ADSR circuits and noodling away with this circuit.

I came to the conclusion that the circuit perhaps lacks a smoother decay and at times a quicker release...it can stutter a little bit.. But hey, this is a circuit with only a Threshhold control.

which I might try some different values with.


Have just noticed Dim's new post, I  would also love to see this circuit get developed further.

Thanks
Mike
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on February 04, 2014, 06:19:19 PM
perhaps lacks a smoother decay and at times a quicker release...it can stutter a little bit.. But hey, this is a circuit with only a Threshhold control.

which I might try some different values with.

Hi Mike, have you tried the said calibration.
Even my Boss NS2 Decay knob sometimes lack in smooth with some such amount of noise.
Regarding Threshold value, 1meg A is such a wide range to find the exact spot and sit where want. Logically, you can limit the range by putting 100k on both left/right of the threshold pot then use A500K, A250k or even A100k if you get what I mean. But as I said mine has serve me well even using single coil with such amount of drive too with acceptable decay.
I'm hoping Larry or someone who also has knowledgeable perspective with LM13700 will try to help add those smarter feature.
 
Title: Re: 13700 Noisegate/Expander
Post by: fendman on February 05, 2014, 11:08:20 AM
Hi Dim, Yeh I have tried the said calibration, using different pedals high gain, fuzz etc some are better than others, I am looking at changing

the pot like you were saying start with A100K see what happens. But like you said it really needs some smarter features, and someone with a lot

more knowledge of design than I have :)

Thanks
Mike
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on February 11, 2014, 06:35:54 PM
Hi Dim, Yeh I have tried the said calibration, using different pedals high gain, fuzz etc some are better than others, I am looking at changing

the pot like you were saying start with A100K see what happens. But like you said it really needs some smarter features, and someone with a lot

more knowledge of design than I have :)

Thanks
Mike

Any progress Mike? Tried in the front of the chain? I find this best in the front before dirt boxes. What do you meant by "better than others"
I know its not superb noisegate but mine functioning well enough. But as I said it only need a send/return and I'm happy with it. I can use it without smart feature (decay/hold/attack)
I'm waiting for a friend to built his Gstring VCA not OTA.
Cheers


I
Title: Re: 13700 Noisegate/Expander
Post by: fendman on February 12, 2014, 06:48:24 PM
Hey Dim, I have been trying to finish old builds...and start the backlog of new ones...You know what its like, never ending :icon_lol:

Anyway,after a lot of experimenting I have ended up useing  an  A100k pot, and have found it gives me no stutter... a better decay and quicker release. I am quite happy with it and will now use it as is..

I  saw you mentioned a Gstring VCA, saw this vid demo and liked the sounds this guy was getting, listen when he activates the switch on the pedal....noise gone.WOW!!!

http://www.youtube.com/watch?feature=player_detailpage&list=PLE8DB7FF3998B093B&v=glww9bJWndo

Enjoy
Mike
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on February 13, 2014, 02:55:34 AM
Hey Dim, I have been trying to finish old builds...and start the backlog of new ones...You know what its like, never ending :icon_lol:

Anyway,after a lot of experimenting I have ended up useing  an  A100k pot, and have found it gives me no stutter... a better decay and quicker release. I am quite happy with it and will now use it as is..

I  saw you mentioned a Gstring VCA, saw this vid demo and liked the sounds this guy was getting, listen when he activates the switch on the pedal....noise gone.WOW!!!

http://www.youtube.com/watch?feature=player_detailpage&list=PLE8DB7FF3998B093B&v=glww9bJWndo

Enjoy
Mike


Glad you also find it useful.. Decimator is also an expander using VCA voltage control amp unlike OTA expander is a current control amp but the same I think(maybe) in principle when it come to gating or noisegate using and design. Yet I sense OTA can be further design and develop to make it more smarter by those who are more knowledgable in OTA. I'm just a musician with low profile in electronic but hey I can build some.  Hope larry and brian will continue to look into it. I'm really tired of FET gate they are unpredictable even with the same value.
I found the Farnell store already my friend  :D 
Maybe our quest for ultimate noisegate will come to an end ( you me and Kipper4). I believe that noisegate plays an important part of a chain even my Boss GT10 multiFX has two built-in noisegate as part of the FX chain.
Cheers,
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on February 13, 2014, 05:55:41 PM
+1

If you looked at the dod fx30 it might help you experiment where to put the side chain (line in ).
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on February 13, 2014, 08:09:19 PM
+1

If you looked at the dod fx30 it might help you experiment where to put the side chain (line in ).

Hey Rich,
I read the dod fx30 at the other forum, its another FET gate design using J113  :'(
Anyway, how long or days does UK first class post would arrive to received a package? My wife ordered 3pcs 4PDT at bitsbox yet never arrived in London. They sent email last FEB10(Monday) that the package was already dispatch. Until now its (Friday) FEB14 Valentine's day....I read on their site it takes only a day....
She already ordered 2 pcs THAT2181CL08-U, 5pcs MPS2222AG/2N5551 at Farnell yesterday.....with UK first class too....dude does it take that long?

No cheers,
Title: Re: 13700 Noisegate/Expander
Post by: Kipper4 on February 14, 2014, 04:01:53 AM
Where are you based.
I'm in England and bits box only takes 3 to4 days max.
Title: Re: 13700 Noisegate/Expander
Post by: DIMstompboxes on February 14, 2014, 05:31:42 PM
Where are you based.
I'm in England and bits box only takes 3 to4 days max.
Uxbridge Road, london
She's looking for bitsbox phone number but to NO avail...no contact number on bitsbox site eek...My concern is one of her colleague schedule flight on FEB24 and shes the one would handed the items for me at the airport. IF ain't delivered before that date... she's gonna send box on APRIL and include those by then wahhah.
Including items that she ordered from Farnell for Gstring yesterday.....I'm keeping my fingers crossed 


Title: Re: 13700 Noisegate/Expander
Post by: disabled_shredder on March 28, 2014, 11:59:05 PM
Hey so I have built the gate only using a 1k for r27 the status led and a tl071 and 2n5088/87 in place of stock transistors q1 is getting to hot to touch I am getting no effected signal but I am getting signal in bypass mode! I do not know what the voltages should be but will measure them and post. Also there are absolutely no solder joints I have checks dozens of times. Does anyone have any idea?
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on March 29, 2014, 01:18:49 AM
You did check the pin out of the 5088/87 right?

They should be facing the opposite way than the BC550s are depicted on the layout.
Title: Re: 13700 Noisegate/Expander
Post by: VahiD on April 20, 2015, 12:47:55 PM
hi , how can change the decay ? i want faster decay plz help
Title: Re: 13700 Noisegate/Expander
Post by: Mark Hammer on April 20, 2015, 06:46:05 PM
It's going to be either R22 or R17.  I don't know which.
Title: Re: 13700 Noisegate/Expander
Post by: VahiD on April 21, 2015, 04:12:50 AM
tnx its r17
lower resistor = faster decay
Title: Re: 13700 Noisegate/Expander
Post by: VahiD on April 21, 2015, 10:41:24 AM
what about other mods ? can anyone help ?
Title: Re: 13700 Noisegate/Expander
Post by: VahiD on April 22, 2015, 02:08:26 PM
why my clean signal change a bit with this pedal ? i have a bit of noise or gain or someting like this in my clean signal and TR1 is not working plz help tnx
Title: Re: 13700 Noisegate/Expander
Post by: VahiD on May 12, 2015, 09:08:06 AM
nobody can tell me why my signal is change ? if you can plz help me
Tnx all
Title: Re: 13700 Noisegate/Expander
Post by: POTL on September 06, 2017, 06:09:20 PM
Hello I came across this project on madbean's website
Someone compared this loudspeaker with ISP Decimator
Or is there nothing better ISP?
Title: Re: 13700 Noisegate/Expander
Post by: armdnrdy on March 24, 2018, 04:06:28 PM
I received a private message for the project file link that was deleted by dropbox.

As requested:

https://www.dropbox.com/s/9eej1fsdldfs7ct/Noise%20Gate%20-%20Expander%20build%20PDF.pdf?dl=0
Title: Re: 13700 Noisegate/Expander
Post by: rankot on June 02, 2018, 05:02:15 PM
Anybody have an idea how to add attack pot to this gate?