Inexpensive Amp for KEF 107s?

I posted earlier about my (mom's) Nakamichi PA-7 woes. We are looking at getting it repaired. In the meanwhile, I'm interested in hearing of some amps that could adequately power the KEF 107 speakers (which the PA-7 has powered for the past 25 years). Budget is no more than $500.
As always, your suggestions are appreciated.
Emjaysea wrote, "No, there is no KUBE, although I don't understand why one would need a subwoofer with these speakers as each one contains a pair of 10 inch woofers and I've certainly never felt they were lacking for bass."

The 107 KUBE is not a sub. It's an active equalizer KEF designed instead of a passive R/C network for crossover transitions. According to the KEF manual, it's required for accurate sound. The 107 KUBE also permits tweeking of HF and LF response, but this can be bypassed. I use 107/2 and 102 KUBEs with Jensen transformers to convert from balanced to unbalanced to go through the KUBEs. I bypass the tweeks.