

If it really is a Yamaha, and if the listed specs are correct, then I'd guess it includes built-in USB audio, just as the PSR-E453 and PSR-E463 do, in which case it requires the Steinberg USB driver, not the Yamaha USB-MIDI driver. On the other hand, the retailer might have put up the wrong image and description by mistake, due to the model's similar name to a PSR-E463, so it might be a Martens PSR-S438 with the wrong image and description shown. But if it's a brand new model from Yamaha then the image might not be of the correct model, such as if the retailer didn't have a picture of the correct model.

In fact, the model number in the image is too blurry to make out but looks like it might be 483 or 463- the last digit looks like a 3 whereas the middle digit does not look like a 3.

Going back to the first ad, not only does the image show a Yamaha, but the description of the specs says that it's a Yamaha, and the listed features seem to be comparable to the latest models, the PSR-E453 and PSR-E463. That second keyboard isn't a Yamaha, but instead is a Martens keyboard, in which case it would presumably be unable to use the Yamaha USB-MIDI driver.
