Amplifying keyboard in a live band can be tough. I play guitar/keys in a classic rock band. I am currently using a Traynor K4 300 watt amp which has a 12 inch speaker and 2 4.5 inch speakers plus some hi frequency tweeters. It is much better than the powered 15 inch PA box I was using before it.

While it can produce a reasonable bass response it doesn't compete with the bass guitar in the band and definately isn't too sharp. It also has a preamp that can be switched between AX7 tube and solid state which provides flexibility. I tend to use the tube most of the time because I like the tube sound for organ sounds. But even still the difference is quite subtle.

Traynor is a Canadian amp company and have been around for many years. While my piano sound through the K4 is not what I would call hifi it works well with with a live rock band. Though that also may be because I always the tube preamp. I think I found it on eBay for about $899.