I have the same problem with Little Pahtty Stage II, Does the firmware update fix it? Or is there a special update to fix this midi problem?
i connected my Slim Phatty via USB and can see it listed as an audio device on my windows computer. i ran the EXE file, and the pop up DOS box says it sent but i am getting no confirmation on the Phatty itself as described by amos. i’ve tried it a number of times, turned everything off and on, and still can get no confirmation that it has updated the USB stuff.
so i got the sp today, scratching my head going pretty nuts trying to find a way to get it going,
i have tried the system, master reset…unplugging my midi controller before booting up the sp and still having dramas.
my test tone works which made me smile for 2 seconds but when i try using my midi controller i have no luck.
i know the controller is sending data because the little black triangle on the left corner of the screen comes up everytime i push a note but i still have no signal comming out of the sp…
someone help please 
im gonna go nuts and end up breaking the stupid thing…
Do you get sound through the headphone jack? If so, is the master output off?
Short question: Does this Mac Installer exist now?
PLEASE HELP AMOS!!! This is bugging me so much. Everything is hooked up right. The only thing not working is midi notes getting sent from moog to ableton or garageband. When i turn nobs on the moog midi signals are picked up, when i write notes in ableton it plays the mood, when i play the keyboard it plays the moog… just no midi notes getting end to ableton that i play on the keyboard… this is my second moog so i sure hope i don’t have to replace this one too
I’ll help if I can. sounds like this is a Little Phatty and not a Slim, correct?
actually I’m not sure. when you say ‘play the keyboard’ do you mean the keyboard on a Little Phatty?
how are you connecting MIDI from the Phatty to the computer? what computer OS?
if you don’t have any custom presets on the phatty you could do a factory restore, that should fix any midi oddness if midi is mostly-working…
what is the OS version displayed on the master menu, system utitilities page?
slim phatty
i did have presets but reset to factory anyways
mac osx 10.7.3
moog is 3.11
usb to mac to send and receive midi. Midi notes are being sent through usb from mac to the moog, but not from the moog to the mac. And midi is being sent to the moog.
problem resolved btw. Had to have DIN IN: set to USB OUT 
Hey guys. I can’t figure out why my MPC 60 (OS 2.02) is not able to play the notes of my Slim Phatty. On the SP, I have gone to the “ENTER = Play Note” page, pressed Cursor, and Enter. It played the sound. I then set up my MPC to Midi control the SP, and when I send Midi, I can see the little MIDI indicator (black triangle) flashing at the bottom left of the LCD. Even with all of this happening, I have no sound when I send MIDI from the MPC.
Before doing all of this, I did the reboot and power cycle without the Midi connected, but it didn’t seem to help. I feel like I’m missing something simple… Does anyone know what’s going on?
I am having the same issue - I see VERS:3.12 680/34
Please help! I just wanna use my amazing Moog…
Seems like i’m not alone being frustrated..
So how’s it going with the mac installer? Im on ver 3.11 647/31 and have been trying everything mentioned in this thread, and getting no sound when using my midi-keyboard, so would be nice to try to install the latest version before i give up and go back to the retailer.
I’m kinda starting to get tired of pressing the “play note” button trying wash some of the frustration away by actually getting to hear this thing..
So now on vers 3.12 and no difference.. Any advice?
Used VMWare Fusion..On OSX 10.6.8 did the update in windows!! worked like a charm..was gonna take this one day old Slim back tomorrow.!!!..WHeeeeeew.. Thanks Amos!!!
Started VM with SP plugged into usb;;A pop up Screen come up and asks "Do you want to use the device with mac or Windows…I chose windows to do the update (update done all good)
2 Shut down VMWare Unplugged Moogs usb… (Ableton would not cause any midi to be sent..I was lost for a bit..but then..Ah HA!!)>>>>>>>
3.restarted VM..with usb plugged into to Moog and the pop up came back and I answered Mac this time which re Established midi out for Ableton! Boom! Done! All knob movements are playing back as Automation!
Hello everyone,
I recently bought a used SP. It was working fine until I got home and tried to connect it to my external midi controller (Alesis QS8.2).
The synth was on, I could toggle through the menus, the presets and all the knob dials were responding. I made sure the channel was set on 1 for the synth and the midi controller. Tested note on, and got a beautifuI sound. I also made sure the output button was on. I even downloaded the user manual in order to make sure everything was setup properly. It is not my first time operating midi devices and studio gear, so I was surprised when I found myself having issues.
I went online and found this forum. I was astonished to find many people were having similar issues with their SPs. most recommended rebooting and reinstalling the firmware. I went to the official moog page, downloaded the appropriate version, and followed the instructions on my mac to perform the reinstallation. To my surprise, instead of getting the Please send firmware message, it got stuck on (usb module), and in the process, erased my previous firmware (version 3.21). Now the SP turns on only to show the same message (usb module).
In the forums I found a post of someone from England, who had a bricked Little Phatty and reflashed the main board using a usb debugger adaptor from Silicon Labs. I ended up getting it, in order to attempt a reflash, with no luck because, the adaptor version I had was not compatible with the Flash utility software found on Silicon Labs website and recommended in the post.
I tried downloading other softwares compatible with the EC3 adaptor also with no luck. I then tried reinstalling the firmware from different computers, mac, pc, windows 7, etc. No luck either. Then i tried connecting other usb and midi cables since I read it is a common issue to have usb and midi off sync. On a post by Amos, he explains how to reflash the usb board only (not the main frame). I also tried that.
Despite not being able to reinstall the firmware, I did get some message activity in the LCD display during some of the troubleshooting. When I tried to reflash the main board with the usb debugger, I finally got the Please send firmware message a couple of times. When I tried to send the firmware it didn not respond or show Receiving.
Then, when i followed instructions to reset the usb board provided by Amos, the SP reacted to data and showed Receiving Record #0, but got stuck and failed to install.
Now that I think about it, it seems the SP had a usb/midi descalibration before I tried to reinstall the firmware the first time, and now with no operating system the SP is bricked and inoperable. I cant seem to find a way to kick it back in sync ( i tried power cycles with and without cables connected to the SP).
Please help!
Franco
Hey sorry to ressurect this old thread but i started having problems receiving midi with the slim phatty and founded this.
I’ve tried to download the Slim_USB_v31.zip file but the link is broken. Tried to search the web but i only get references to this thread so im kinda stuck.
Anyone has the file still? If so please DM me. Thanks in advance1
November 2024 annnnnnd - Still relevant!! Same enquiry as above - I am tired of this hit & miss MIDI mission.. Love the SP, but it’s no good if it can’t be played and I don’t want to sell it on whilst it’s basically a pretty paper weight that lights up.
Would love a link to Slim_USB_v31.zip file please - can’t believe the link wasn’t maintained
Your problem still exsist?
Go to moogmusic.com than go to downloads than synthesizer scroll down to legacy products than go to phatty than to the firmware the last point is the slim phatty firmware v3_21
Hmm… this is the “whole” Slim Phatty OS, but I’m quite sure our friends are actually searching for the USB firmware file.