Ric, given the choice strictly between the JRDG 625 mk2 & Capri 2 or Raidho C3.1's, I would go for the upgraded Rowland amps. The reason being the Raidho's have very average build quality & are way over-priced imho. And I know from whence I speak. I tried to sell a pair and they are boat ankers. The Rowland amps otoh have a solid reputation and generally good 2nd hand value.
But I agree with Mechans that a better pair of loudspeakers will have a greater impact on the sound of your system vs an amp upgrade. I was recently faced with the same choice; upgrading to Vitus separates from my current SIA-025 or upgrading my speakers. The latter option won, and the Magico S7's are currently front runner for my next pair of speakers.
If you're prepared to consider any other speaker options, I would look at a good 2nd hand pair of Proac Carbon 8's, Magico S5's or Vandersteen 5a carbons. Or even a new pair of Revel Ultima Salon 2's. And given the prodigious power of your JRDG amp, if you have a medium-large room with an even front wall, you could also consider a new pair of Graz-authorized resto'd Apogee Diva's such as the TSW Diva Ultimates.
But I agree with Mechans that a better pair of loudspeakers will have a greater impact on the sound of your system vs an amp upgrade. I was recently faced with the same choice; upgrading to Vitus separates from my current SIA-025 or upgrading my speakers. The latter option won, and the Magico S7's are currently front runner for my next pair of speakers.
If you're prepared to consider any other speaker options, I would look at a good 2nd hand pair of Proac Carbon 8's, Magico S5's or Vandersteen 5a carbons. Or even a new pair of Revel Ultima Salon 2's. And given the prodigious power of your JRDG amp, if you have a medium-large room with an even front wall, you could also consider a new pair of Graz-authorized resto'd Apogee Diva's such as the TSW Diva Ultimates.