I have noticed some amp builds using Diodes instead of a rectifier tube like a 5Y3. What I am not finding is the specs on the diodes. I read people saying use a uf4007 diode, but are there different values. Do they come rated for volts and watts. So say I want to build a champ what uf4007 diode would I use, or does any garden variety do the job. Any help or direction would be appreciated. Cheers Ron.