The trem of an AC30 or the vib of an AC30??
Either way it's a pretty unique sound, but...the trem will be easier to cop in a pedal.
I have a twin reverb and it has the vib so I don't need anything vib. I just want a nice warm trem
Twin Reverb says...vibrato, but that is a tremolo effect. You will not get any pitch modulation with a Fender 'vibrato' channel. What you are asking for sounds like a Tremolo...which the Twin has. (Only its labeled wrong. LOL!)
The EH Wiggler comes to mind.