As stated, with the appropriate speaker cable or adaptor, you can plug in a cab with only a 1/4"-phone input connector. Do note that because it's a Class D amp and is likely to employ an internal bridging topology, be careful not to short the tip and sleeve of the quarter-phone plug while the amp is operating, which can sometimes happen when plugging or unplugging the quarter-phone. The safest thing to do is just to not do that while the amp is turned on. Likewise, don't let the bare metal sleeve of the quarter-phone plug touch anything thing else that's likely to be grounded -- like the chassis of this (or another) amp or a grounded AC outlet box -- while the amp is operating. Again, just don't do any patching with the quarter-phone end while the amp is on and you should be fine.
