Documentation on Katana 50 FX Loop

[Romulusrex]

I've seen a bit of talk about this, and it seems at one point ColorMaker managed to successfully mod a katana 50 to include an fx loop, but since then they've gone silent on their youtube channel and in the forum, so I thought I'd open a new thread and see if we can work something out. To add a bit of value to the new conversation though, I did manage to find the katana 50 mkii service manual, as well as the 100 mki one.

As many guessed, it seems to be the unpopulated CS6 connectors that go to the send/return for the fx loop in the katana 100:




Here's the same drawing for the katana 50 populated up to pin 9:



So, question is - does anyone here know how to do this stuff?




Here's the full service manual files also. Can't find 100mkii unfortunately, but I don't think there's any changes to this part of the circuitry...

Has anyone got any good ideas about how to proceed from here? It'd be awesome if we could add fx loops properly. Alternatively if ColorMaker or anyone else who's succeeded want to let us know what they did differently, that'd be awesome too!

[Elantric]

Colormaker wants $$ to share the info

And after performing this FX Loop MOD, good luck obtaining Service from any repair center today, as most will refuse to work on "modified Katana  amplifiers".  And given that bulk of Katanas are owned by young inexperienced guitarists, results in a situation with high likelihood of failure , as many have zero experience with electronics.  Katanas tend to fail if care is not exercised during disassembly/reassembly - just google search on  "Boss Katana - no sound"

https://www.google.com/search?q=Boss+Katana+-+no+sound&oq=Boss+Katana+-+no+sound&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIICAEQABgWGB4yCAgCEAAYFhgeMgoIAxAAGIYDGIoFMgoIBBAAGIYDGIoFMgoIBRAAGIYDGIoFMgoIBhAAGIYDGIoFMgoIBxAAGIYDGIoF0gEIMzczNWowajeoAgCwAgA&client=ms-android-samsung-gs-rev1&sourceid=chrome-mobile&ie=UTF-8
https://www.vguitarforums.com/smf/index.php?topic=25686.0

[gumtown]

You won't be able to use the Kat 50 empty component spaces on the board as the Send/Return is disabled in the firmware on the Kat 50.

I am sure the mod was simply cutting into the power amp line signal in the circuit board and installing a basic send/return
(which does not use the send D/A and return A/D converters, nor any software control over the levels).

Its really a job not worth the time & effort,
 if you were to send the katana 50 away to be mod'ed and returned,
 it would cost more than the value of the Kat 100 that you should have brought instead.   

[Romulusrex]

if you were to send the katana 50 away to be mod'ed and returned,
 it would cost more than the value of the Kat 100 that you should have brought instead.   

Of course, I realise it costs a fortune to pay anyone else to do anything, but I thought the point of this forum was about working stuff out yourself, hence the DIY tag.

Can you elaborate on what you mean by a basic send/return before the power amp? I've done a lot of electronics, but not with audio before. I assume it's not just as simple as wiring in two female jack sockets into the power amp line-in cable?

[Elantric]

Just google adding FX loop to amp , image search reveals a diagram .
https://www.google.com/search?q=diy+guitar+amp+fx+loop&tbm=isch&ved=2ahUKEwiyhaCuvfiAAxXSPUQIHTogDGoQ2-cCegQIABAA&oq=diy+guitar+amp+fx+loop&gs_lcp=CgNpbWcQAzoECCMQJ1CxC1jfEmCfFWgAcAB4AIABigGIAdAEkgEDMS40mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei=PPjoZLL3GdL7kPIPusCw0AY&client=ms-android-samsung-gs-rev1

While we provide DIY diagrams to add missing features on gear - in this case of Katana 50 FX Loop, its a world full of plentiful used  Katana 100 amps  available, skip the drill and soldering iron and high risk of failure,  best path is acquire a Katana 100 - sell Katana 50 , fund a used Katana 100  - would be lower expenditure of labor , tools, and better outcome with a usable fully adjustable Send & return level FX Loop in Katana 100