Er…why would you possibly need A/D converters in the USB interface! :zonked:

Whatever is going over the USB bus is digital, everything else in the OT is also digital from when it arrives at the inputs or until it is sent out of the outputs (where the A/D and D/A converters are already in place). There’s no internal analog signal path because being a sampler, it’s an all-digital instrument, and there’s no analog coming or going over a USB cable.

Re the Microprocessor, audio gear usually has 2 main digital chips, the Digital Signal Processor (from Frrescale or Sharc, IIRC the OT is Freescale) which handles all the sound-warping/effects stuff, and the microcontroller which handles the user interface, the data from the front panel, and all the data housekeeping - all the non-audio stuff in the OS basically. The Analog four/keys/Rytm also have an FPGA which handles all the’plumbing’ for the analog circuits and allows rapid reconfiguration in real time, but that’s not really relevant here.

Sending audio to/from USB requires a chipset at the device end to make it c’lass compliant’ (which the OT apparently doesn’t have) but it doesn’t involve much in the way of signal processing, power, if any, because you’re not doing anything to the audio other than routing it to a particular destination; in this respect it’s a plumbing problem. It’s like the buss buttons on an analog mixer, all they do is split off another copy of that channel to a another bus in addition to the main outputs. The main point of the different chipset for realtime audio is that (in a simple explanation) you have to share an audio clock with the converters so that everything is happening synchronously in the device, otherwise you would get constantly changing latency and so on. It uses standards called I2S (signal) and I2C (control), and obviously these chips aren’t present in the OT (I wonder why not as it seems a missed opportunity and the technology has been around for a long time, but that’s another question).

I do hope there will be the possibility of an upgrade though; I haven’t checked to see if there are any expansion headers inside the OT. It is definitely something I’d pay for.

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