80 bass accordion ( with dim triad 7ths = 96 bass )

[wirralaccordion]

I have seen a piano accordion for sale which is described as "Marinucci 80 bass (with dim triad 7ths =96bass)"

What does this mean?

Would this accordion be heavier than the same standard 80 bass accordion and lighter than the same 96 bass accordion?

 

[TomBR]

The bass buttons furthest from the bellows would play three notes in intervals of a minor third, hence a diminished chord.
Those three notes would be the third, fifth and seventh of a seventh chord, so you get both diminished and what you need for a seventh from one button. So if you play it right, you can do nearly all of what a 96 bass layout with separate seventh and dim rows will do.
But you have to press the correct button!

I'd say no weight difference to any other 80 bass, a little bit lighter than a 96, naturally.

 

[losthobos]

Little diffence in weight as still has same amount reeds
7th chord is composed of 3,5,7 omitting Root.... This allows the adjacent 7th to double as a dim triad... Ie F7 button doubles as Cdim
I play this system on my smaller Maugein
Works fine for me though some prefer the normal stradella voixe that omits the 5th rather than the root
Hope that's helpful

 

[donn]

Already multiple answers on what it means. As for whether it would be lighter - no, not just on account of the bass side. Once there are reeds for every note, which happens at 60/72, no? (my brain feels a little unreliable this morning), then more buttons just use the same reeds, and the buttons and the little rods that they activate weigh next to nothing.

There are undoubtedly a number of factors that go into making an accordion heavy. I suppose you could shave off pounds in the external and internal construction, with no change to musical parameters. But the number of voices seems like perhaps the first place one might look, and after that the number of treble notes.