Sounds OK to me since you're placing a line-level signal onto the next preamp input anyway. No doubdt it's amplified but wouldn't be to an overload level if you don't crank the volume controll all-the-way open on the tuner-pre.
It certainly won't interfear with any other components hooked-up to your current preamp safety-wise but whenever other components you're playing I'd suggest the tuner(or any other RF device) to be powered off(or at least you can switch to different mode your tuner-pre that basically powers tuner off).
It certainly won't interfear with any other components hooked-up to your current preamp safety-wise but whenever other components you're playing I'd suggest the tuner(or any other RF device) to be powered off(or at least you can switch to different mode your tuner-pre that basically powers tuner off).