I recently picked up an Electroharmonix #1 Echo Delay. The pedal is super simple...blend, time and feedback are the only three knobs. The blend knob all the way to the left is 100% dry, all the way to the right 100% wet. I think the pedal sounds great but here's the problem. I run it in the effects loop of my Marshall and when the blend knob gets around 9 o'clock I start losing volume of the dry signal. At 12 o'clock the original signal and the delay are the same volume but the overall signal is weakened. This does not happen when I run it in front of the amp, only in the loop.

The quality sounds much nicer in the loop but the loss in volume is driving me nuts! Help

Is this what people call "tone suck?" Its not so much tone loss but volume.