DECIMATOR II G-STRING advice

[njkmonty]

i have the "that 2181c" chip   
few years  go  i used a layout i found floating around , but it didnt sound right, was a bit fizzy so i gave up on it.
ive seen some with dual opamps and some with quads?
since then ive come across various threads indicating i might have used an old and incorrect schematic.
any one here who has actually built the decimator or g string, advise what the correct schematic layout is, as i want to give it one more chance?
thank you in advance!

[Vlad123]

Have you tried with those?
http://revolutiondeux.blogspot.com/2012/07/isp-decimator-noise-reduction-system.html

[temol]

I've built one using this schemtic

T.

[J0K3RX]

Look here..
http://the7line.clan.su/publ/diystompbox/noise_gate/2-1-0-35

Sprint files
http://the7line.clan.su/files/Decimator_II.zip
http://the7line.clan.su/files/3.5_jack_board.zip

[njkmonty]

thanks!

[pinkjimiphoton]

i can vouch for this guy's board and project, worked great right out of the gate once i learned to wrap my head around the weird way it hooks up...

the guitar goes to guitar in. guitar out goes to the input of your effects. return goes to the OUTPUT of your effects, out goes to your amp. its a brilliant piece of kit imho

you can run it in front of a fuzzface and it will still work right, cuz the guitar out is for all intents just a jumper from the guitar in jack.

https://guitar-electronics.eu/en_US/p/DECIMATOR-G-STRING-PCB/230

here's the build doc, and this one is good and works

https://guitar-electronics.eu/en_US/p/file/a36abf2f22e3e40508430446a234645f/Decimator-G-String-ENG.pdf

[njkmonty]

Cheers thanks!!

[Kennt82]

I built  the Version 1 using  Sabro's layout. There's a G- string addon and after I figured out the connection, like  Jimi says, it works really well.  But thanks for the v2  info, J0K3RX!   Did you make a pcb?

[pinkjimiphoton]

it took me forever to figure out how to patch it together, lol... guitar goes in, then guitar out goes to the fx chain in, guitar return is the output of the chain, and then the output goes to your amp or time/modulation. its a killer piece of kit. cuzza the way it works, if will even play nice with a ge fuzzface.

[caspercody]

I finished this vero board last night.

I colored the +9 volts with red jumpers, ground with green jumpers, 1/2 voltage with blue jumpers, and jumpers are in white.

I created the vero board using Sabrotone's Decimator I layout. I have not built it yet, and if anyone sees anything that needs to be changed please let me know

Also, if you have anything for the G string portion, please let me know?

Also attached is BOM. The BOM is missing the 10K B Threshold pot.

[abakuzam]

i have the "that 2181c" chip   
few years  go  i used a layout i found floating around , but it didnt sound right, was a bit fizzy so i gave up on it.
ive seen some with dual opamps and some with quads?
since then ive come across various threads indicating i might have used an old and incorrect schematic.
any one here who has actually built the decimator or g string, advise what the correct schematic layout is, as i want to give it one more chance?
thank you in advance!

Hello,

i have built this pedal before, had a few issues while trying to get it to work, i posted some voltages after i get it to work, you may want to check this thread if you want to go with the same layout

https://www.diystompboxes.com/smfforum/index.php?topic=121425.msg1141319#msg1141319

[tonyamme]

someone has already tried to build the version of Noise Gate II described at this link
https://the7line.clan.su/publ/diystompbox/noise_gate/2-1-0-35
Thanks

[icziko]

Old topic, but maybe it will help someone.
I built Sabrotone layout and after some problems it works great. I added G-String add-on, however little bit modified to the same way as pinkjimiphoton mentioned: the Guitar Out (SEND) should not be buffered as it is shown on add-on layout but rather linked with Guitar In (INPUT). I believe schematic provided here is accurate for G-String add-on.
https://guitar-electronics.eu/en_US/p/file/a36abf2f22e3e40508430446a234645f/Decimator-G-String-ENG.pdf

Such information can be also found on ISP site:
https://www.isptechnologies.com/product-hook-up-faq/
Quote:
"
QUESTION:
Is there a buffer in the Decimator G-String pedal, and if so where is it placed?

ANSWER:
The Decimator G String does not have a buffer between Guitar IN and Guitar OUT. We did this so as to avoid any noise intrusion between the Guitar output and the input of the rig being used. With extremely high gain rigs even a buffer amplifier can add more noise than the straight guitar signal. We use a very high impedance tap of this Guitar IN signal to derive the Decimator control signal right from the Guitar. There is a buffer between the Decimator IN and Decimator OUT so even with the G String switched out there is a Buffer in this signal path.
"

This noise gate is fantastic, it might be worth to change Threshold potentiometer range change f.eq. by adding 22K resistor between pin 1 and pin 3 of potentiometer.

[wcraffonara]

Hi,
  I'm trying o figure out how to add the G-String-Mod to this Decimator II.
Does anybody know how to add this functionality to the schematic provided by "the 7th line project" NOISE GATE 2?
https://the7line.clan.su/publ/diystompbox/noise_gate/2-1-0-35

Thank you very much!

Best regards
Walter

[rankot]

Hi,
  I'm trying o figure out how to add the G-String-Mod to this Decimator II.
Does anybody know how to add this functionality to the schematic provided by "the 7th line project" NOISE GATE 2?
https://the7line.clan.su/publ/diystompbox/noise_gate/2-1-0-35

Thank you very much!

Best regards
Walter

I don't know, cause I didn't build it, but I've found two different layouts:
http://guitar-fx-layouts.238.s1.nabble.com/ISP-Decimator-g-string-addon-td29992.html
https://diy-layout.com/75

Please post the solution if you try.

[wcraffonara]

Thank you for the links. I already have the schematic of the G-String-Mod.
I will try to figure out how to merge both parts.

[rankot]

Could you please share that schematic here, just for convenience. I have that build in my wish list, but wasn't sure about that mod.

[pinkjimiphoton]

yeah, this is the one i built, works phenomenally

but its weird, doesnt hook up like you'd think.


https://guitar-electronics.eu/en_US/p/file/a36abf2f22e3e40508430446a234645f/Decimator-G-String-ENG.pdf

guitar goes in, then guitar out goes to the fx chain in, guitar return is the output of the chain, and then the output goes to your amp or time/modulation.

[wcraffonara]

Hi,
  I've already build the Decimator G-String from
https://guitar-electronics.eu/en_US/p/file/a36abf2f22e3e40508430446a234645f/Decimator-G-String-ENG.pdf

and it works perfectly!
Now, I would like to check out the latest version of the Decimator G-String II.

If I compare all the schematic versions of the Decimator and Decimator G-String then I'm pretty sure I've figured out how to add the G-String part to the Decimator G-String II schematic provided by The 7th Line (https://the7line.clan.su/publ/diystompbox/noise_gate/2-2-0-35?oeRZuYd).

Here is my proposal:


- R16 is R14 from The 7th Line schematic
- C18 is C3 from The 7th Line schematic
- The G-String (left part of the schematic) provides a buffer for the Guitar Input and if LINK_IN is not connected then the guitar signal goes to the noise-cancelling circuit.
- If you link two of these pedals using the LINK_IN and LINK_OUT connectors then you provide the buffered (original) guitar signal to the noise-cancelling circuit of the second pedal.
- gIN is the DEC IN of the pedal

What do you think about this proposal?