I've owned... a few too many of these already, and they are good horns. Like most makers, though, the big downside is the bells. The 613 and 6130 bells are... ok. They are a little thin and lack some depth that other makes could get consistently. The 8130, a Japan only model, is thicker rose brass and is quite a good bell... but they're harder to find.
What's interesting is that the dimensions of those Yamaha bells, and to an extent the tuning slides as well, are largely the same as Bachs. Hmm...
Something a little less hard to find is a good 50 bell that's paired with a... less than desirable valve section. Bach has had pretty much the opposite problem, spinning great bells and using the same valves from the '40s assembled as quickly as possible.
I recently lucked into TWO Yamahas on ebay with wrecked bells- the first 8130 had a split in the rim, and the 6130 bell had some huge dents (and is much less desirable anyway).
I also had a very good Corp 50 bell in yellow on a 50B2 that had been damaged, with a messed up valve knuckle and generally just not good.
I recently bought a very early Elkhart 50BG single.
Here's the result!
On the left is that yellow bell on the 8130 valve section, using the Yamaha tuning slide. This was about as easy a swap as possible, literally torching off the old bell, then soldering on the new one. The only thing that moved was socketing the main bell flange towards the bell a bit.
On the right is the gold bell, using the original 50 tuning slide and a 50B lower receiver as well.
On both of these horns I use original Yamaha 8130 slides- the 6130 came with a 8130 slide as well, for some reason. The 8130 has a better leadpipe and general construction (as well as real oversleeves) than the normal 613 slides.
So how do they play? In most ways, they feel to the face much like the Yamahas they spring from. Very easy, quick response, great valve registers, very few quirks. These aren't M&Ws or Greenhoes, but they are very easy horns to play.
The big change is the sound- they sound like very, very good examples of 50s. Loud, colorful, no dead zones, broad. I'd say they are slightly less orchestral than a 50 with Thayers, but just better in every way than almost every stock rotor Bach.
My M&W is unsurprisingly better- it's more even, it's broader, more orchestral. But these are a great horn for a more diverse set of needs. Really happy with how they turned out.
