Holly, so long as the voltage on the supply is correct (the 707 is 13 or so
volts) its not going to be a problem. The supply you're looking at is a higher
amperage than you need but that won't matter. I use the same supply for bh my
707 and my 570. Ths 570 requires a much higher amperage but there's no problem.
The higher amperage just means you've potentially got more power at your
disposal. The voltage is the only thing in the supply that you have to watch so
long as the amperage is sufficient. I'd have to double check with the manual
but I'm thinking the amperage required for the 707 is 13 amps.
Tom
Tom Brennan KD5VIJ, CCC-A/SLP
web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html