THAT4301 RetroFit Module

Paradox916

Well-known member
A14E8003-7786-4ACD-B943-31F395A4096B.jpeg C4F7B4AB-E86C-4785-AAE8-9774D81A4FCC.jpeg 3F3735D8-6090-4CA5-A6C4-B2095AF89E4E.jpeg 7584A987-EC26-4E0F-9060-4250857D6CD4.jpeg ADA0F2CE-F77B-4E8F-8CC4-E424847E4AA8.jpeg Well this isn’t really a build report per se as I used an existing muzzle build to note any differences between the actual 4301 and the retrofit with 4305.... hers is the skinny on what I experienced.. the module using 2.54mm pin headers sits about the same as the 4301 In a IC socket and a few mm higher using a IC socket with the module (obviously) but even with the socket it fits in the muzzle specified layout quite snugg... the switched side chain jack are a little tight, you can get them in there but you will have to remove all unnecessary terminals on the switched jacks.. and trim the protruding header pins from the module. There is little room for error in regards to drilling the side chain jack holes.. if you aren’t super confident in your fab skills You might want to think about forgoing the IC socket (So the module sits lower or using a larger enclosure(then you will have room for days. As for the performance of the module, it holds true to the technical data as (far as I can tell.) that it seems to actually have slightly better performance and clarity over the 4301. If you were wanting to build a muzzle I hope you find this helpful and you will not be disappointed.
 
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This is cool, I'd like to see a schematic how this fits in and how it replaces the 4301 if you have that or can point me in a direction.
Also: where did you get the 4305 chip please? Cheers!
 

The module comes with all components presolderd all you have to do is solder the pin headers and it’s a plug and play. If you already have a That4301 chip I wouldn’t worry about it,the performance upgrade isn’t that noticeable. I just wanted to see if there was a difference.

If you wanted the tech data I can dig that up again this was something I was looking into but PPCB came out with this which was much easier than figuring out how all the R&D.
 
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Thank you for the write up. I'm still waiting on my module in the mail. I appreciate the comment about careful location of the side jacks.
 
Old thread, but I had trouble with the THAT4301 RetroFit Module, so I build the PCB again. The first time I had to used this new mini PCB I noticed that there's not enough room to fit this mini PCB because the socket IC of the LT1054, and there' not enough room to fit the SPDT next the THAT4301 chip.
So, that first time, I used to cut and file a little bit the upper board of the mini PCB and the spot on the side where the SPDT touch the PCB.

Anyway, this time I want to avoid this process and make the right space to fit all the things.
 
Old thread, but I had trouble with the THAT4301 RetroFit Module, so I build the PCB again. The first time I had to used this new mini PCB I noticed that there's not enough room to fit this mini PCB because the socket IC of the LT1054, and there' not enough room to fit the SPDT next the THAT4301 chip.
So, that first time, I used to cut and file a little bit the upper board of the mini PCB and the spot on the side where the SPDT touch the PCB.

Anyway, this time I want to avoid this process and make the right space to fit all the things.
I have yet to see someone cut or file on a pcb and it work out. There is room for everything in this build although it will be very packed and tight, component selection and placing is paramount along with some mindful planing, I recommend dry fitting components before soldering if necessary to make sure everything will clear. Take your time it will work out.
 
I'll take my time to mount everything, I have to include just the Key input, not the side output.

With the old built there was, apparently, a bad THAT chip, unfortunately I had to solder it directly (thing I never do, but I had to, this time).
Ground and +9v was ok on all the ICs, but in the THAT chip other pin was around 0.00v. It gates noise and sound, but I just can choose between noise or sputtering sound.

I'm doing it again with a new chip, I hope that will be ok.
 
Hi @Paradox916,

Could you give me some clear explanation about the IC That 4305 in the thread you have ever nicely answered?

I thought I mounted it at the wrong side but seeing your pics , I did like you and the Muzzle kit doesn' t work ...

You can see my question there:


Thx a lot

Regards

Bruno
 
Hi @Paradox916,

Could you give me some clear explanation about the IC That 4305 in the thread you have ever nicely answered?

I thought I mounted it at the wrong side but seeing your pics , I did like you and the Muzzle kit doesn' t work ...

You can see my question there:


Thx a lot

Regards

Bruno
I’m a little fuzzy on what it is your questions are, and in the spirit of total transparency, although I am a fan of this chip set and circuit I am far from an expert. But it sounds like you need to open up a troubleshooting thread with clear pictures of your build. And that would be a good starting point to see if you can get it working.
 
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