This or THAT??? Decimator question

[Guybrush]

Hi gang,

I'm looking to build PCB Guitar Mania's take of the Decimator - the Noise Terminator https://pcbguitarmania.com/product/noise-terminator/

the BOM calls for a THAT 2181 chip but I'm unsure what precise version of the chip I need.

My go-to parts site, Das Musikding, lists 3 versions in the correct packaging:

THAT 2181CL08-U
THAT 2181BL08-U
THAT 2181AL08-U

These can be seen here -https://www.banzaimusic.com/search.php?mode=search&page=1&keep_https=yes

Edit: link doesn't work.

Is anyone able to point me in the direction of the one I need please?

It's the most expensive one isn't it?   

Cheers!

[madbean]

Those are ranked by THD, "A" being the smallest. For a guitar noise gate the C version is fine. Or split the difference with B.

[Guybrush]

Everyday is a school day here.

Thanks Bean. Much appreciated as always.

[Zerro]

Most of signal from guitar, when you play, will mask background noise between notes you play. Most annoying noise, hiss or hum, is heard when sound will decay out (if signal is not really dramatically poluted with noise). So problems with attack-decay setting is not so cruel here for staccato playing, as described. Mostly some simple semi-passive Gate would work without problem.

Here is one (enhanced) simple gate with minimal settings needs.

[Guybrush]

Super helpful. I'll take a look. Thanks!

[Govmnt_Lacky]

I believe both the original and the G-string used the 2181C version.

[Muadzin]

Most of signal from guitar, when you play, will mask background noise between notes you play. Most annoying noise, hiss or hum, is heard when sound will decay out (if signal is not really dramatically poluted with noise). So problems with attack-decay setting is not so cruel here for staccato playing, as described. Mostly some simple semi-passive Gate would work without problem.

Here is one (enhanced) simple gate with minimal settings needs.

I've tried and built many noise gates, IMHO none can hold a candle to the Decimator. The one I haven't tried and which may be better, even though I got one is Glenn Fricker's Cockblocker.

[madbean]

I've tried and built many noise gates, IMHO none can hold a candle to the Decimator. The one I haven't tried and which may be better, even though I got one is Glenn Fricker's Cockblocker.

Yeah my Decimator build has never left the pedalboard. It's pretty great.
I have a noise gate idea I've been kicking around based on the THAT 4305. It's borrows a bit from the Fortin Zuul and also one of the THAT application notes. Haven't tried building it yet. I really should add something like that to the mbp project list eventually.

[jimilee]

When I was gigging, mine was always on too.


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[Guybrush]

This is all good to hear. I'll be ordering the parts today.

Looking forward to seeing your noise gate Brian.

Two noise gates on one board isn't overkill is it?

Thanks

[Guybrush]

Ignore - duplicated post. 
See below.

[Guybrush]

One more parts question please.

The BOM calls for an LF353N chip but my parts place only has a LF353P. Do I need to look elsewhere or will the N do the trick? I've read that a OPA2134 or even a TL072 can be used but thought it best to confirm with someone knowledgable here.

I've done a bit of googling but, typically, found conflicting info.

EDIT: Gahh, it also needs a MPS2222a which seem to be pretty hard to get hold of over in the UK/Europe. Can anyone advise on alternatives? A 2N2222 perhaps?

Thank you.

[Zerro]

TL072 will work with no problem. MPS2222 is general purpose NPN transistor; you can use any similar one, BC237, 238 ....

[Guybrush]

TL072 will work with no problem. MPS2222 is general purpose NPN transistor; you can use any similar one, BC237, 238 ....

Thank you!

Still struggling finding a BC237 or BC238. I have found a listing for a BC547A that mentions it's a repalcement for the BC237A so I'm assuming that'll do the trick.

Thanks again.

[Zerro]

BC547 will work too without any problem.