How cheap? Discontinued AT-LP120 or new X version AT-LP120X? Does it need a new stylus?
What’s the difference between a TS cable and TRS cable?
The JBL or Nobsound should work.
More options:
Low cost Level Controller.
Monitor controllers with pro audio connections:
Or a Stereo Preamp with RCA inputs and output.
Or use a mixer.
What did you have the HS5 connected to before you acquired the turntable?
Or don't connect the turntable to the interface, bypass the interface.
Turntable > monitor controller, mixer or stereo preamp and all give you unified volume control > HS5
Nobsound Little Bear MC2 Balanced/Single-Ended Passive Preamp XLR/RCA Volume Controller for Active Monitor Speakers has both RCA and XLR inputs and outputs.
DYNASTY PROAUDIO PMC-2 Premium Passive 2 x 2 Studio Monitor Volume Controller has XLR, TRS, RCA, 3.5mm inputs and XLR, TRS, 3.5mm outputs.
Artesia EZA-MC2 Passive Stereo Monitor Controller has TRS, RCA and 3.5mm inputs and XLR, TRS and 3.5mm outputs.
Instead of digitizing the analog turntable audio signal try bypassing the digital interface and computer and connecting the turntable to the studio monitors with a level controller, a monitor controller, mixer or stereo preamp.
Monitor controllers to connect both the turntable and the interface so you can switch between them:
Stereo Preamp with RCA inputs and output.
Don't expect vinyl to sound as good as digital, it's just different with it's own sound and quirks.
Wet clean new and used records.
What have you had the Kali connected to?
Turntable > phono preamp > level controller, monitor controller, mixer or stereo preamp > studio monitors.
Phono preamps:
Volume control, 2 input switch and phono preamp:
RCA volume control:
Volume control and switching with multiple connection formats:
Connect both the turntable and the audio interface to a monitor controller, mixer, or stereo preamp that then connects to the studio monitors. This gives you unified volume control and the ability to mix or switch between the turntable and audio interface.
Monitor controllers:
None of them.
Connect both the turntable and the Focusrite to a stereo preamp, a mixer or a monitor controller for unified volume control and to switch between the turntable and Focusrite or mix both together with the mixer.
Nobsound Little Bear MC2 Balanced/Single-Ended Passive Preamp XLR/RCA Volume Controller for Active Monitor Speakers has both RCA and XLR inputs and outputs.
DYNASTY PROAUDIO PMC-2 Premium Passive 2 x 2 Studio Monitor Volume Controller has XLR, TRS, RCA, 3.5mm inputs and XLR, TRS, 3.5mm outputs.
Artesia EZA-MC2 Passive Stereo Monitor Controller has TRS, RCA and 3.5mm inputs and XLR, TRS and 3.5mm outputs.
Or other options from Mackie or Behringer or other brands.
Which model monitors?
Consider bypassing the audio interface and connect both the turntable and the audio interface to a monitor controller, mixer, or stereo preamp with volume control that then connects to the studio monitors.
Stereo preamp: Schiit Sys RCA 2 input switch with volume control.
Monitor controllers: