You can go through the laptop by connecting B3 to it and then play while listening to YouTube (essentially the laptop becomes the mixer -- you might have to adjust something from the sound mixer program in Windows). You can connect the B3 as a USB audio interface or just plug its output to the sound input of the laptop if there is one (sometimes there's a mic input that you must disable its "boost", for it to work as line input). But in both solutions (USB vs laptop input) you go through a sound card that might have latency, i.e. your playing could be arriving at your ears 1/6 of the second late or something, in which case you would have to fiddle with some option somewhere to fix it.
Or, you could get a Vox amPlug (or a Joyo Super Lead, even cheaper: Amazon.com: Mini Guitar Headphone Amp Pocket Amplifier Super Lead Sound Joyo JA-03: Musical Instruments), as old spice said.
Or, you could get a Vox amPlug (or a Joyo Super Lead, even cheaper: Amazon.com: Mini Guitar Headphone Amp Pocket Amplifier Super Lead Sound Joyo JA-03: Musical Instruments), as old spice said.
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