Using output as attenuator?

[docgorpon]

I have a rack delay unit I use in the loop of my tube amp. It has both input and output levels that can be adjusted. I initially had it set to where the amp's volume level without the unit was about the same as with the unit in place.
However, the input indicator on the unit showed that I needed much more juice coming into it as it wasn't even registering. So I can either crank the input of the unit way up or turn the amp way up. Either way, it's above my normal playing volume. So I turn the output down. If I use the option to turn the amp up (seems like the thing to do rather than diming the input level on the unit), and turn the output of the unit down to make up for the increased volume, then my amp is running quite a bit quieter than when the unit is unplugged.
Is this alright?