Vintage tube equipment will do the trick. Some of the modern stuff will, but a lot of it isn't quite as warm as the older pieces. Vintage is priced all over the place, depending on your budget.
Be sure it is already checked out and in top condition by someone who KNOWS what he is doing BEFORE you spend your money.
Be sure it is already checked out and in top condition by someone who KNOWS what he is doing BEFORE you spend your money.