Based on their design, I would have guessed that the Cambridge speakers would have a lot of low end emphasis. As suggested above, have you verified that the speakers are connected properly? If polarity is wrong, they will not sound good, and bass can be significantly reduced.
If wired correctly, and assuming that all four woofers are in working order, it just boils down to you preferring the sound of the Technics speakers over the Cambridge.
Better amps can certainly improve the performance of one's speakers, but I would not expect any improvement in amps to make a dramatic difference with how either pair of your speakers sound.
Between your Technics amp and the 2252, the Marantz is a better amp (assuming good working condition)....but again, I don't think one vs the other is going to make your speakers sound significantly better.
Either will be fine. However, if you are looking towards moving up the ladder a bit over time, it's a good idea to start with a good amp...something with enough power to drive a wide range of speakers, and do it well. Then you can try different speakers with the assurance that what you are hearing is mostly the sound of the source component and your speakers (a good amp has no characteristic sound).
Get a good amp, and then work your way through speakers until you find a pair that makes you happy. If you are happy now, stop!