Toning down reverb in Fillmore 50

Way too much reverb in Fillmore 50. Tube switch to adjust?

As for me, I never cared too much for the Mesa reverb in my Fillmore 100 combo(Or my Lonestar 100 head either...) I use an Electro-Harmonix 'Oceans 11' in the effects loop of the Fillmore and a Strymon 'Flint' for the LS. Problems solved.

(I apologize, my reply wasn't the proper answer to your question...)

You could try a 12AU7 in V5. Or a tube that's 1/2 12AX7 and 1/2 12AU7 in V4. Or both.

I'm not a fan of my Fillmore's reverb either. But my LSC is the best spring verb I've ever heard in the warm setting.

I got a Fillmore 50 head a couple of weeks ago. I love the amp. It's exactly what I hoped it would be. The only thing that is disappointing is the reverb as you mentioned. Having read your post earlier I tried a few different 12AX7, 12AT7 and one 12AU7 in V5 (V5A is Reverb Return and V5B is Reverb send). With the 12AU7 it made the reverb minimal even when turned all the way up, so that essentially nullified the reverb totally. Also the 12AU7 had a negative effect on the amp overall, even when the Reverb was turned all the way down (off). With a 12AT7 in V5 it gave the reverb a much more usable range of the control, and it seems to have a somewhat better sound. It's possible the sound of the reverb isn't a lot different but that it seems better because of the control being less sensitive, but it does seem a little better to me. The 12AT7 doesn't have a negative effect on the amps tones or response either (putting 12AT7 in all the slots would reduce the gain and overall output of the amp, but just one in V5 doesn't have a noticeable negative effect). I tried a few different NOS and current production 12AT7 and 12AX7 in V5 and was surprised to learn that even with the reverb turned completely off the tube used in V5 affected the sound of the amp with different tubes producing different textures and either more or less clear tones in overdrive or distortion.

So based on my experience this evening it seems switching out the V5 12AZX7 tube for a 12AT7 can be an effective option to potentially improve the reverb a little without negative effects on the amps tone or response. The reverb is still not great, and the best option might be changing out the reverb tank for a higher quality tank.