Just converted my Iida from a resonator to an open back. Man, I love what you can do with this TPF, it is so versatile. With the new Sullivan rim, it is also be very pretty and it still sounds great, just not quite as loud. Even though it does still have a full size bell brass flathead tone ring.
I did end up putting some small flat washers under the nuts but the bottom of the tube is already flattened as Helix and Ken had said. I will probably end up getting some nuts that are more appropriate for an openback but this is plenty good to try it out.
Just wanted to show others how this could come out and what versatility the TPF offers.
For some reason I've always liked a TPF over a OPF. The versatility is nice, and I also like the look better as well. And as a bonus I think they're usually lighter weight.
I have two pre-war flat tops with one piece flanges and two pre-war arch tops with two piece flanges. The archtops get infinitely more playing time because I like the sound better.
Is this mostly because of the tone ring, the flange, a combination of both, or my tedious hearing?
I did the same with my Recording King R30.
I have a couple of other really good sounding open backs, so I'm still trying to decide if I like this well enough to justify the added weight of the flathead tone ring.
'Yamaha Mt03' 1 hr
'Deering Artisan Parlor' 4 hrs
'Renaissance Head' 4 hrs