This is very confusing and extremely difficult to nail down because of all the tradeoffs.

First, none of the modern interfaces have any on board sound except for the Sonic Cell. I have a SC and it works great. It's a full Roland hardware synth including a nice GM sondbank that retails for about $700. I bought mine used for $400. Things change so fast I probably shouldn't say none, maybe there's others now. Most are like you indicated, input/output devices. My $500 EMU 1820M has midi in/out, two XLR mic inputs and eight RCA ins/outs. This is for multitrack live recording. My SC is a good interface, the ASIO works fine but it's only got one combo XLR and 1/4" input with a line in and two 1/4" stereo outs. Not good for multitracking like my 1820M. The 1820M has no built in synths or other sound but it has a very complex and sophisticated PatchMix digital mixer. Not a physical mixer. I don't believe any of them come with a physical mixer but I think Tascam and/or Mackie have a fairly expensive physical mixer that will interface with their regular interface. I see the SC is now discontinued so I don't know if anything is available to replace it.

You said this:

Quote:

I have seen write ups for midi / audio interfaces such as some focusrite models that sound as though they are complete recording systems in and of themselves and would work thru Real band or similar recording software such as cubase etc, even if my computer had no sound source of its own.



This is confusing. If you installed a softsynth like the VSC or Forte DXi, then your conputer has an internal sound source, right? Every computer has a built in sound chip on the mobo so they all have a built in "sound source".

I mentioned tradeoffs. The biggest one is do you like being able to do direct rendering or not? Direct rendering requires software VSTI or DXi synths, it won't work with external hardware synths. If you're using hardware then you have to route the audio output from a synth like my SC, back into your interface, the 1820M in my case, route it internally to Real Band or other DAW and record your finished song in real time as it plays back. A five minute song takes five minutes while a direct render may only take 20-30 seconds.

The way you worded your conclusion sounds like you need a good multi in/out interface similar to my EMU. With that you can use either your internal softsynths or external hardware. Something like my SC with a full synth plus multiple ins/outs that also acts as an interface may not exist.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.