22-10-2011, 10:40 AM
I was looking to improve my Laney with a couple of mods to finally sort out the "as manufactured" rather duff phase splitter and the endemic under bias on the output pair.. and while hunting I came across a site with a lot of circuits and very in-depth discussion of how the circuits work in theory and in real world situations. Have a look, the amplifiers section in particular should be a fantastic help in understanding why certain circuits were chosen over others, and especially when faced with a circuit which has design faults how to remedy them. Back in the day when valves were cheap and easy to obtain designers would sometimes run things right on the edge or even go over.. My Laney is a perfect example, designed when fantastic EL34 outputs were cheap as chips, Mullard or military spec CV numbered and able to take a bit of overload, running a heap of grid current with the screens too high in cathode self bias was fine.. these days with new JJ's running at about £80 a pair (and not up to the spec of the military/Mullard originals) it's not good economics to overrun them in this way. Also for guitar amp restorers I have a few bits of knowledge which will be useful to anybody faced with a WEM or Triumph amp that is suddenly silent on an EL84 replacement (or anything with an EL84 output)
Check out the link, there is lots to read and absorb, and there is even a "sister" site dealing with transistor things.
http://www.angelfire.com/electronic/funw...index.html
Check out the link, there is lots to read and absorb, and there is even a "sister" site dealing with transistor things.
http://www.angelfire.com/electronic/funw...index.html
