I have the THR10C.....it's the "bluesy" version. Really like it alot. Just plug it in and play. Nice low sound, great amp sims. Yamaha hit a home run with this one. I never use it with batteries though. This is a problem with this amp, it doesn't sound as good without electrical current running through it. Maybe they fixed the problem but it was a long-term issue with this amp. But, it is stellar as a desk-top amp.