The easiest fix is to try plugging into input 2 of the channel instead of input 1. That should clean up and tighten your sound a bit. Another free tip is to try turning down your guitar’s volume knob from 10 to 9 or 8. It won’t kill your volume too much, but it should cause your pedals to clean up just a bit, which might help.

You could also use your amp’s tone controls to your advantage. A quirk of Fender’s blackface-era, 3-knob tone control circuit is that the “mid” knob actually works like a volume control instead of a true midrange control. The only reason midrange seems to be affected is because of a quirk of the human ear that naturally accentuates the midrange once it gets above a certain volume level. Try setting your tone up with the amp’s volume on 3, but the midrange on 10 and add treble and bass to taste. It will be louder than you might think and you might get your sound back.

Also, Santana’s classic sound was achieved by him plugging straight into with a Boogie Mark 1 prototype, which is just a tweed Fender Bassman clone with a master volume added and driving a 12″ speaker. He cranked it up to 10 and then used the sheer volume feeding back from the amp to accentuate his sustain. Your Super Reverb already gets a sound very close to that amp, so It should be very easy for you to get close to his sound. You may not even have to use any pedals, just try turning your amp up. It will get more natural compression and your guitar will sustain more as you turn the volume up. After that you can add pedals to taste.

If you’re willing to spend a little bit of coin, I’d recommend looking into a compressor pedal like the MXR Dynacomp. If you set it to a moderate sensitivity setting, it’ll give you more sustain and a clean volume boost without your sound losing focus. I have one and it has become indispensable to my sound, especially as a boost for solos and when I want more sustain from my rig.