Hey Erik- Not sure exactly what sound you're describing but the equipment you have should be adequate to get a broad range of sounds. The DS-1 is not a bad pedal but make sure you are running it thru the clean channel on your amp - if you compound pedal distortion and amp distortion you (may) get a muddy result. Also, do not run it thru the effects loop - run it between ur guitar and amp. I don't know how many watts ur tube amp is but if it is 20+ watts you may have to crank it up pretty loud to get to it's "cruising altitude" where it sounds it's best. U might try cutting ur midrange control on ur amp (maybe even to "0") and have the LEVEL on the pedal past 12:00.
I'm no pro...I been dickin' w/gear for decades and these are the thots I had when I read ur post. Just trying to help a brother :)