TromboneChat

I've noticed more eBay listings showing up recently from Japanese sellers for Yamaha 'Custom' series trombones (4-digit model numbers). The sellers never describe the specs of these 'Custom' horn other than cosmetic stuff.

I haven't found anything online (catalogs, etc) for these 4-digit horns: YSL-8420, YSL-8425, or YSL-8440

Looking for bore sizes, main differences from each other, main differences between these and their 3-digit cousins.

Thanks in advance!

These are the older, second generation of the Custom line (the first gen is the 842 and 844, identifiable by the lack of tuning silde cross brace). The 8420 and 8425 are large bore (.551” if I remember correctly) symphonic horns, although I am not sure about the difference between the 0 and the 5. The 8440 is a medium bore (.525”) horn. The naming convention can be compared to the YSL-620 and YSL-640.

The main difference between these and the newer YSL-820G and 820GII (current) is the valve mechanism. The older ones have string linkage, while the 820G and GII have mechanical linkage. There may be some other internal and metal thickness difference, along with cosmatic changes.