Since my amp connects via USB, I don’t need a seperate audio interface?
If the guitar is one input and you use a separate channel for a microphone then that makes two inputs, yes.
There are interface boxes with multiple inputs that plug into a single USB socket, and OTOH there are simple and cheap 6.5mm to USB cables that connect your guitar to USB but obviously have no other channels. There are also portable digital recorders like this that include a USB interface and a microphone and also let you plug more stuff (microphone or line level) into it for multi-channel input. What is your current set-up?
Would this work? I have a Mustang amp but it doesn’t have an output other than USB
https://www.sweetwater.com/store/detail/UCA222--behringer-u-control-uca222-usb-audio-interface
It has two RCA inputs, but I do not see a microphone input (assuming that is what you are trying to do?) Unless you have a microphone preamp you can use. The guitar is already amplified by the guitar amp, which has a USB output. You only need to worry about any non-guitar inputs you may need.
Something like this with an RCA adapter cable?
this looks easier
https://www.sweetwater.com/store/detail/UM2usb--behringer-u-phoria-um2-usb-audio-interface
That does appear to be a preamp that you can plug both an instrument and a microphone into. What it does not have is a DAC or any kind of USB output.
That looks like the kind of combo you want. Mic preamp, USB interface, and you could plug your guitar into it as well if you felt like it.
Great, and for a mic I see the Shure SM 57 reccommended as a good starter mic
An SM 57 is one gold standard for amplified instrument micing. Are you doing that, or are you planning to sing into the mic?
Both of them
SM 58 is the vocal version of that same mic. You could certainly use that for micing a speaker also.
what I will do is get my me and my brothers set up with soundjack and try it with just electric and see if it works, before spending money on a mic and interface. Thanks for the help!
Have Soundjackk installed and connected throught ethernet and audio interface. On the state page, I see through local host 15 mbps and through own peer on NAT router 15.5 mbps. Should both of those be one, and regarless, 15 is not low enough is it? Do I need to have of those on or just one. But beyond that, what do I do next, how to I play the guitar? I don’t see a way to select and input like on Audacity? Does it have video? Oh and JamTuner will not connect
15 megabits is more than enough. Or do you mean that you have 15 ms latency? Your goal is to decrease that as much as possible (subject to some physical limits); 15 ms may be perceptible, but it really should be OK, especially just for testing.
Now if it’s working there should be a settings area with, among other things, icons that look like a rectangle with arrows going into/out of it. That is where you should be able to select your audio interface device for input and for output. (You should make sure that your guitar and mic are correctly working through your audio interface before worrying about Soundjack, for instance if you can record them in Audacity then it is working.) For output you can use headphones or any other device.
To try it out, you are supposed to connect to another person who is also running Soundjack and test that you can connect to and hear each other. Soundjack does have video, but I have not tested it. I believe there are some video tutorials on how to use everything; I will check. What do you mean about JamTuner?
I meant ms, it goes between 15 and 23. JamTuner turns out to be a public room, another user I guess. Local host would be me I guess and there is another called mabes (my nickname). Do I just need to connect to one of these?
Working with Audacity, and now I see a device list on Soundjack , one is PCM2902 USB codec, Audacity finds Microphone USB Codec so I guess they are the same
Now I can hear a crackling sound but nothing else
Well now Soundjack is not recognizing the audio interface at all. I tried JamKazam and it recognizes it, I think (USB input codec) but when I record something and play back, no volume
I know from the instructions that when using Windows you need to select the ASIO version of the audio interface driver from the menu, if you have a choice.
That is how it is supposed to work. That would be what you select for the input.
I believe only one program can grab the interface at the same time (barring special tricks). So you should close Audacity and all other programs before running Soundjack.
It sounds like JamTuner is another user, probably one of the developers. He may have been testing something in the public room, but understandable if he did not feel like chatting with you at the time 
However, there is a Soundjack text chat and forums if you really run into technical problems. So far, though, you have not described any weird behaviour, it sounds OK.
There is an echo test you can perform by yourself. If you see a user with a name like “Mirror — Virginia” or something like that, you can connect to it, and it will echo back your audio.
Eventually best thing to do would be if you found another user (not JamTuner, I mean your brother, or a friend, or someone from the soundjack chat who is willing to help you out) and try to connect to them in a private room, or the public room, it doesn’t matter. Once their name shows up you should be able to click on the icon next to it to connect to them.
BTW you, or at least one of you, may need to open ports in your firewall if you are getting firewalled (the status can be seen in the gray pop-up menu that shows up when you hover or click on the green circle with an “i” for “info” in it).
Optimizing the latency to decrease it as much as possible should only be the last step, after you have everything else working.
There are a bunch of demonstration videos on 10 SJ-Commandments - Soundjack , not sure how up-to-date they are though.
thanks for those detailed instructions, but we will not be using soundjack, the video is beta and the site says it can cause crashes. I was able to get JamKazzam to work. It is not free but the plan with 10 hours per month is just $4.99 a month, my brother will pay that as I am paying for Zoom every month. I has a really good interface and was easy to set up.
We have not tested it playing together, will do so this week when my brother’s ethernet cable is delivered. He was just using wifi for internet, as I was.
I also have a Shure M57 mic coming for acoustic, I was going to get the M58 but I would rather the mic be better for my Martin than my “signing” voice.
Which reminds me of a line from the great John Prine, who had throat surgery. His doctor was concerned about how it would affect his singing. And Prine said, “Have you ever heard me sing? If I can talk when I get out of here I’ll be ok.”
Heheh, as was said before. They’re largely the same mic except for the windscreen. It’ll work for both, even if you don’t have Prine’s natural talent. 