No, Onix and Melody have no relation to each other whatsoever. The only connection is that the Onix tube amplifiers sold a few years back were rebadged Melody amps. Melody also builds Mystere on behalf of PrimaLuna and built the Genesis I60 and M60 monos a few years back.
Angel City Audio is the US distributor for both Onix and Melody, but we're dropping Onix and liquidating that gear so we can focus more on Melody and the new ACA branded products.