Upgrade speaker cables OR amp for Dynaudio C4's?

With all due respect to Albert... I'd stick with SS on the C4s. I'm sure there are a few high powered tube amps to drive them, but as others have noted, it will require a lot of tubes, and will put off a lot of heat.

I'd look into a higher powered SS amp. The Harmonic cables should be fine. I'd say high current, with 500WPC into 4 ohms for these.

How big is your room? I hope those C4s have some breathing space, because they open up with current.

I had the Plinius 102 on a pair of Dyn S1.4s, which was a great match. The Plinius sound complements Dyns well, so you could look into a used 250. Also, I'd consider McIntosh, Sim, and the JC-1 as mentioned above.

To all: Thanks for your input / advice. I was thrilled to wake up to so much feedback on my question.

Albert - You have instant credibility in my book and you have been quite helpful to me in the past when I've asked your advice. Your suggestion of powerful VTL tube amps is intriguing, and it has passed my mind several times before. I'm quite certain the sound would be top-shelf, however, given the issues with heat, blown fuses & tubes, I think I'd probably be too stressed out to be consistently happy with them. I tend to like gear that's relatively trouble free.

Dave - Thanks for the speaker cable recommendation. I'm not very familiar with MIT's offerings. I've always been a bit leery of their products because there always seems to be a large glut of inventory available. I'll do some research on the Magnum M3.

Eljif - I think following your advice on getting higher powered amplification is sound. I do love my SA-102 and am hesitant to part with it. So as it stands right now, I may wait for another SA-102 to come available in the states and run them as bridged mono-blocks with 400 WPC into 8 ohms.

Bob - After an initial rough patch, my Aesthetix preamp was adjusted to operate in the low gain setting & is working nicely with the Plinius amp. Tube rolling with NOS tubes has made a night & day difference with the sound quality achievable in the Calypso. It's a keeper.

Goatwuss - My room is 21' x 15' and partially open-ended on the far wall perpendicular to the speakers. The front of the speakers are 62" from the front wall and a min. of 36" off the side walls. The room was acoustically treated with GIK panels... made a HUGE difference ;).

Pdreher..I own C4s at present in the same size room,running a mac 402 into them..I had a Pass labs x.5 and really regret selling it..mated well,very well..Ive seen your post in the past and never felt the Plinius was the right choice.IMO tubes are the wrong direction..Two guys I personally know had problems with the JC1 amps,plus the heat,forgetaboutit..again my opinion..Try different cables or other tweeks when the amp situation is taken care of..Given your short list the Pass X250.0 or if you can swing it the 350.5 is a no brainer with the C4s

Missioncoonery is correct. As I said, if power is an issue I would go high power SS then tweak the cables.