I just installed a Dannick no-hole tone ring in my Gibson Blackjack RB-75. I really debated installing it because (with the exception of the 4th string), the setup priot to installing the Dannick produced great clarity up and down the neck. I've searched most all afternoon here on the HO and the net to learn what a no-hole ring will produce. Most everything I read suggested the no-hole ring would work best in a mahogany banjo..which the Blackjack is.
I decided to give it a shot as you never know what result you'll get unless you try. I took it down and installed the new ring. WOW..what a difference in the 4th and overall volume. The 4th string growls now. Clarity is there..may have lost a little above the 15th fret but at this point my ears are worn out. I'll continue critique in the morning.