Instruct: Classify Amazon reviews into positive or negative sentiment
Query: The Tube Amp Book - Good, but not a DIY guide

I am building a 50 watt tube amp based off of Marshall & Fender designs; somewhat of a hybrid. I bought this for the schematics and such. The book is more of a history of tube amps, info on the parts/tubes & schematics, but it is not a DIY book. If you do not know what you are doing and you want to build your own amp, this book will not be a help. If you already know how to build one and need schematics and would also like to know the history of amps and the parts, this is good book for that. Also as stated in previous reviews, the schematics can be very hard to read, some are handwritten or bad copies, but with some work, can be read.