deHavilland has a remote stepped attenuator for their pre-amps. I've been using their products for years and am extremely happy with them.
http://www.dehavillandhifi.com/Products%20Page.htm
http://www.dehavillandhifi.com/TW_remote_volume_control_is_the.htm
Feel free to send me an e mail and I can tell you more about it.
http://www.dehavillandhifi.com/Products%20Page.htm
http://www.dehavillandhifi.com/TW_remote_volume_control_is_the.htm
Feel free to send me an e mail and I can tell you more about it.