Stagg EDA40

Hi
I have just bought a Stagg EDA40 drum amp and am having problems getting the damn thing to give me some decent sound!
I have an Alesis DM6.
The Stagg has 2 channels; 1 is AUX; and the other is a Left + Right (Left being the single use Mono) with Gain and compressor controls.
I have tried using;
1, a single stereo output cable to the Left (mono);
2, stereo outputs to Left + Right;
3, single cable to the AUX.

The AUX gives me plenty of volume, but no Gain etc controls.
The Left (Mono) and the Left + Right options do give me gain etc, but very little volume.
Anyone know if I'm doing something wrong?

Thanks

Are you using this cable for the main output? If you are using a balanced cable there might be some cancellation on the stereo inputs of the amp.