He does play an older Jupiter, and these often come without any logo. The bass sound from their typical setup: the large reed block for the lowest note not only has the large L and M reeds but also adds two higher reeds, making for a 4-voice bass. On these older bayans there are no registers so you always get the deep LM sound plus the higher reeds for a very "full" sound. Then you have 2 or 3 notes that are just LM without extra reeds, and all the higher notes are LL (giving you that "flute" sound). Newer Russian bayans have a register switch to disable the extra reeds in the lowest octave, for a deep bass without the fullness (sharpness) of the higher reeds added. There are no other options. You always have LM for the lowest 15 notes and LL for all higher notes. On the one hand that may appear to be a limitation, but on the other hand it lets you play low and high, where low has a full sound and high has a "flute" sound, without the need for changing registers. Italian accordion makers have copied this in what they call "bayan" accordions, like the old Pigini Sirius, and added register switches later to allow for a single L reed for instance (because the bayans were a hard sell without registers). But they have always struggled in making the transition from the lowest bass notes to the higher notes sound natural and smooth.