P68 Esp Pages

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Erm, Hi Guys!

As per normal i could use a little help.

I'm building a active pa system for my a level electronics project.

I've got a pair of 15in peavey tops (tweeters need changing) and i'm currently mid way through building a few of Rog the Gods HD15 subs loaded with some Eminence Kappa 15's.

Obviously as a student, the cash is always tight so to power the lot i was planning to build 4 p68's of the esp pages, 2 X 300w jobbies for the tops and 2 X 500w for the bottoms.

I have all MJL21193/4's and the MJE340/50 for the drivers, my only real problem is the pcb's. I have photo capabilities in college to make the pcb's but i'm unsure of what i should be considering. People always talking of short feedback lines and loads of other important stuff when building high power amplifiers and to be honest, i don't really know where to start. I am competant at making pcb's, but i'm more used to huge microcontroller circuits.

Could anyone point me in the right direction, or if anyone's got an existing one i could have a nose at? All help as usual would be much appreciated!

Cheers Muchly,..

Matt



*** EDIT ***

Also, as part of the project i was going to implement some limiters, as i have always been a fan of pushing the volume, i like to know i CANT damage the amps, not MAY NOT damage them. Has anyone got any decent schematics, preferably ones that dont induce lots of distortion etc, thinking like the ddt on peavey's? but i'm honestly going off that one, every big bass note drops the volume of everything drastically! just any simple but effective ideas would be useful.

I thank you all again, as usual!
 
Unfortunately Rod's PCB layouts are a closely guarded secret, unless you buy one :)

To be honest, have a good look at other PCB layouts for other Class AB amplifiers, and lay the P68 out the same way. The feedback trace should be as short as possible, and come directly from the speaker output terminal on the board. If possible try and keep the high current traces for the output stage away from the signal traces, make sure miller caps are kept close to their respective transistors, and so on.

I would suggest P68's for your woofers but P3A for the tweeters. The P68 is not designed for great high frequency response as it is designed to power a subwoofer. You can use the same parts for both amps anyway so it's not as if you'd have to buy anything new.

I would also suggest MJL4281/4302 for the P68's as they handle more power than the 21193/4's. I'm not sure about MJE340/350 as drivers but they seem pretty common, maybe try to get MJE15034/15035 for drivers. You can get em all from OnSemi as samples, theyll charge about $17 shipping but they'll let you order a lot of parts for that.

Make sure you use a good large heatsink :)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.