Concerning the Stagg ADBA 40 combo, that is supposed to go with EUB: very natural sound of a double bass, much more natural as with a standard electronic bass amplifier. Coupled with that is a reduced loundness for the 40W combo, a standard bass combo with 40W usually has much more boum. It sounds more like a PA then an instrument combo. Besides the instrument connection (only 47kOhm, you need a pre-amplifier for piezo), there is a microphone connection without shadow voltage. That can be used to amplify a double bass without any modification. Can be helpfull with filling a not to big room for a performance. Beside amplifying an EUB, probably would be very good for a singer/songwriter needing a microphone and guitar amplification.