Curious About This Hardware - USAMO

I have never seen this hardware previously, and I think it may be something relatively new from ES. I am posting it because I looked it up and found a relatively basic answer about what the USAMO is:

The Expert Sleepers USAMO (Universal Sample-Accurate MIDI Output) provides a sample-accurate, jitter-free MIDI output from your DAW.

The MIDI signal is generated by the USAMO software, a plug-in which runs as a virtual instrument (AU/VST/AAX, Mac & Windows), as audio in your DAW. The DAW sends MIDI to the plug-in; the plug-in translates that to audio and sends it to the USAMO hardware, via an output on your computer’s audio interface. The USAMO then reconstructs the MIDI and outputs it on a standard 5 pin DIN MIDI socket.

In addition to MIDI note and controller data from the DAW, the USAMO software also generates MIDI clock, Song Position Pointer etc. It can also handle Sysex.

Because the MIDI signals are generated and transported as audio, they are guaranteed to be sample-accurately synced with your audio, and free of the jitter often associated with computer-generated MIDI

So I know what it does, but that seems like a job many already existent audio interfaces can take on, like the MOTU M4, PreSonus iTwo, or many of the other similarly affordable externals that cost not much more than this (seemingly) singularly focused MIDI only device.

It made me curious enough to wonder about, but I can’t ask a search engine the way I can just pose a question here. I was just wondering if anyone knows anything about this?

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I think the difference is the MIDI interface on most audio interfaces is actually separate from the audio portion of the interface. The DAW sends MIDI to the MIDI section and audio to the audio section. The audio from the DAW is handed off to the operating system’s audio software chain and the MIDI is handed off to the O/S’s MIDI transport. Because the audio and MIDI data are processed separately by the DAW and operating system there can be small variations in timing between the audio and MIDI data. In this case everything is audio from the perspective of the DAW and O/S so it’s all handled in the same fashion. The USAMO hardware converts its incoming audio to MIDI with the aim of reducing the amount of jitter.

I think that in most cases this is a solution looking for a problem. I’ve never noticed any jitter on my DAW generated MIDI sufficient to cause an issue. I admit I’ve never measured it, but since my digital synths have a fair amount of jitter in their latency in any case, I doubt it would make any difference to the final result.

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Ok, that makes sense. I am just beginning to put together a basic understanding of how direct MIDI works as a series of messages.

As far as processing/transforming through a DAW (especially when adding clock data, encoded modulation info, and MMC messages, or duplicating and/or filtering messages to other channels :exploding_head:), that is where the clearly understood ideas turn to hieroglyphics and the diagram of that factory :factory: in my head looks like :thinking::

step1: ‘input from controller’ [:musical_keyboard:]


step2: ‘computer does something…’ [:desktop_computer::thought_balloon::question:]


step3: ‘profit’ [:notes::musical_note:]

Your quick and thorough answer definitely was better, and more to the point than hours spent trying to figure out the right way to state what I was looking for to ask Dr. Internet’s Inquiry Machine :man_shrugging:

Thanks for the reply, @stschoen :smiley:


It’s a mystery to me as well. I can only comment on what I observe personally and I’ve never had a problem. Perhaps I’m not perceptive enough to detect the jitter.

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