Lee,
I can recommend the new Ultrasound 250 watt combo to you. It was recently introduced at the Namm Show and is going into production, soon. I think it is great for the extended ranges like those of a guitar synth. It's actually an acoustic guitar amp and is a biamp configuration with two resident speakers and horns. It works great for a 7 string, and bass too..so, it should work for your 8 string. Since it is high output, it has a lot of headroom and no limiters or compressors like typical acoustic guitar amps.....This one is a killer....It has two channels, digital effects, and lots of output possibilities...stereo line out, mono line out, xlr direct out...you name it. For more info on it contact Dan Gore at Ultraamps@aol.com. Hope I've been of some help to you.
Best Regards,
Wayne Wesley Johnson
Wannadu, LLC
7 Avenida Vista Grande #-260
Santa Fe, NM 87508
phone: 505.466.8700
fax: 505.466.8702
email: Wjguitar@aol.com or WannaduLLC@aol.com
website: http://wannadu.com
