instruments. The Dobro name has undergone several ownership changes throughout history, and has been owned by Gibson Guitar Corporation since 1993. Gibson manufactured Dobro branded instruments under its Epiphone division up to 2020. Since then, no Dobro branded instruments have been produced. The Regal name, similar to Dobro, has been bought and sold several times since its original owners went defunct; the name has been a brand of Saga Musical Instruments since 1987. US patents #1,741,453 covering the tricone. #1,896,484 covering the Dobro. #1,808,756 covering the biscuit single cone resonator, lodged in the name of Beauchamp. See also Brahms guitar, a classical guitar that features an external resonator. Slide guitar References External links Resonator guitars Chanticleer (UK), maker of resophonic instruments Resonators Explained by Paul Kucharski American fretted musical instrument makers (pre-Civil War to WWII) Notecannons – Vintage resonator guitars Acoustic guitars Continuous pitch instruments Resophonic instruments