Jeff, I do not know of any books that pertain specifically to tweaking/modding amps.
However there is a lot of information on the net. Arthur Salvatore has a nice intro into modding tube equipment, which you may find helpful when starting out. I found a lot of useful information on bulletin boards and many time builders (both private and commercial) give tips on their web pages.
Also there are a couple of capacitor shootouts on the web. Have a look at http://www.vhaudio.com/21capacitorshootout.pdf and http://diyparadise.com/cap/dare_to_compare.html. There are many more.
Regards
Paul
However there is a lot of information on the net. Arthur Salvatore has a nice intro into modding tube equipment, which you may find helpful when starting out. I found a lot of useful information on bulletin boards and many time builders (both private and commercial) give tips on their web pages.
Also there are a couple of capacitor shootouts on the web. Have a look at http://www.vhaudio.com/21capacitorshootout.pdf and http://diyparadise.com/cap/dare_to_compare.html. There are many more.
Regards
Paul