Rob Thankyou for your input. I have never thought of doing it this way but it sounds as if it might be an easier option for me. Mayb less stressful than trying to sing play and look decent all at the same time lol ? what do you think of the sm58 for recording? I’m really only doing this for a bit of fun and would only be posting online for friends, still would like to sound as good as is possible. I’ve always used the sm58 for singing and playing guitar live but know nothing about the technical equipment needed for recording. Have recorded an album for Cancer Research a few years ago but hired someone to do it professionally. If you can sugggest some idiot proof way of using what gear I already have eg the Yamaha pass 300 and the Roland Cube ex? Even ifihave to buy a condenser mic? I do have 3 sm58’s already tho ?? Any advice most welcome Thankyou!!
Jumping in - apologies...
It does not look, to me, like either the Yamaha StagePass 300 or Roland CUBE Street EX have phantom power, which would be required for a condenser microphone (to keep it simple).
I may have scanned too quickly, but when you perform live, do you plug in the guitar, or use one of the SM58 mics to capture its sound?
It's not entirely clear what you expect outcome to look like, in terms of audio and video quality, or anything. The simplest option is to just get a clamp/adapter that holds your current/modern smartphone, put it on a mic stand or camera tripod, and record yourself singing and playing in a good sounding and looking space. There are lots of videos done like that which do not look bad, and there are [no doubt] videos done with more equipment that look and sound worse. If nothing else, it gives you a good baseline on how to judge your performance and "stage presence" in the kind of video you are contemplating.
I've never done a "dubbie" kind of video, but it is typical to record the audio and video separately, i.e., with one device recording video, and another recording audio. In fact, there's probably not many (any?)
professional videos that are done in any other way, because that allows different people to focus on those aspects, which are both important for a polished result.
Which brings me to my favorite "dead horse," and that' the fact that it's [exceedingly] rare where you can get a good video
and place the recording equipment in the exact same spot as the camera(s) and capture good audio. That's the limitation of using a smartphone, or combination a/v recorder of any kind.
If you want to "step up" in the audio recording, you'll have to figure out how to capture that with something other than the video recorder, or, at least, separate the capture, and then feed that to the camera. Perhaps the most direct/common is to take a feed from your recording gear, e.g., the CUBE, using a LINE out and input that directly to the camera. The higher-end DSLRs often have a 3.5mm (1/8") stereo feed that take a line level signal (with some menu setting!) and record the mixer audio along with the video, skipping the camera's built-in mics (which are in the wrong place!). Actually, backing up from that is to get a small stereo mic, probably battery powered, though it may obtain power from the camera, and place that optimally for recording audio, running a long-enough cable to the video camera. You can also find external mics that plug into smartphones, but they tend to be at the end of short-ish cables, so do usually give you as much positioning options as necessary.
Next is to just record the audio separately. You could use something like a small digital recorder on a stand, like a Zoom H2n, record the audio with its built-in mics, and sync it to video recorded on a separate device. You import the audio and video files into your favorite video editor, and sync them up so the sound matches the video. In the process you remove any audio recorded by the DSLR/video/cam-recorder/smartphone, leaving just the track recorded by the audio device. You can make it a bit more complex by adding more microphones and/or direct (plugged-in) guitar/keyboards either to a digital recorder with multiple inputs to support that, or, indirectly, going through a mixer, and, again, taking the line out and sending that to a digital recorder with compatible inputs.
Sorry for the "book" - good luck!