I ran the Source speakers with a 3311ci (125W) for quite a while and it worked fairly well, no issues at all with volume or quality. It even drove the combined Source + Stage center with no real problems.
Last year, I upgraded to the X6400H and it made a HUGE difference. The monolith discrete amp design does a fairly decent job even with the smaller panel MLs. More importantly the DACs, power supply, overall build quality/design put it in a different league.
For sure using the X3000 as a pre is an option. But be mindful the pre-out quality will be average at best since it’s a mid-range receiver.
All depends on how critical of a listener you are and your budget. You may be happier just getting a higher end receiver first. You will get better and more modern HDMI and processing capabilities, better amps, and far better pre-outs for future use. If that is limiting then get a lower cost external amp.
The Source speakers have small panels so they are MUCH easier to drive than the larger ML panels. The bigger the panel the more importance goes to the amplification and source. When you move up to the bigger panels (like Impression 11A up) you really need an external amp, they are very revealing and will definitely dip below 2ohm on the higher frequencies.
PM if you want to discuss further, I spent a lot of time with the Source speakers, especially with Denon receivers, external amps, and various speaker cables, etc.
UPDATE: @caphill has a good point above - if you have the budget, a AV8802 + external amp will be a far nicer and longer term solution. The only thing to think about is you will be spending WAY more than the value of your speakers. FWIW, I upgraded to the ML 11As and in doing so I added a McIntosh mc452 amp. For the 11A's they were night and day addition. When I tried them with the Source speakers the difference was marginal at best. Sure they sounded nicer, just not sure the Source speakers are as demanding as the bigger panels.
Last year, I upgraded to the X6400H and it made a HUGE difference. The monolith discrete amp design does a fairly decent job even with the smaller panel MLs. More importantly the DACs, power supply, overall build quality/design put it in a different league.
For sure using the X3000 as a pre is an option. But be mindful the pre-out quality will be average at best since it’s a mid-range receiver.
All depends on how critical of a listener you are and your budget. You may be happier just getting a higher end receiver first. You will get better and more modern HDMI and processing capabilities, better amps, and far better pre-outs for future use. If that is limiting then get a lower cost external amp.
The Source speakers have small panels so they are MUCH easier to drive than the larger ML panels. The bigger the panel the more importance goes to the amplification and source. When you move up to the bigger panels (like Impression 11A up) you really need an external amp, they are very revealing and will definitely dip below 2ohm on the higher frequencies.
PM if you want to discuss further, I spent a lot of time with the Source speakers, especially with Denon receivers, external amps, and various speaker cables, etc.
UPDATE: @caphill has a good point above - if you have the budget, a AV8802 + external amp will be a far nicer and longer term solution. The only thing to think about is you will be spending WAY more than the value of your speakers. FWIW, I upgraded to the ML 11As and in doing so I added a McIntosh mc452 amp. For the 11A's they were night and day addition. When I tried them with the Source speakers the difference was marginal at best. Sure they sounded nicer, just not sure the Source speakers are as demanding as the bigger panels.