Got my PL 400 from a band that had it mounted in a home made enclosure with a handle on top.
One channel blown.
Now I brought it up to the 21st century with the WOAL .
Works first time ! I'm really amazed.
Very powerful too.
I make sure to have one on every amp. W.O. or not. Pushing it in any circumstance gets 'em too warm for MY tastes. Plus it's just good practice. I have a couple ready to get installed.........................................
There is a very nice guy whom I have dealt with on ebay who restores and or makes the shrouds. You can buy the fan as a whole kit OR if you are enough of a decent human being to him, he'll do business with you with just getting you the shrouds you seek. I have spoken to him personally on the phone several times. Couldn't be a nicer fella. His ratings perfect, and he has a HUGE collection of PL gear. Read his ebay posting and you'll see he's no stranger to the gear.
Some people don't like what's available today in a 120VAC fan. They cool FAST but they do so because they run FAST. And when you run fast you hear it. I have 8 going at once so you might expect it to sound like you just stepped into a server room right? NO. Yeah I hear it, but once you turn the volume to level 2 - they are drowned out. Now be honest, who here is gonna play the 700B with light classical music on at volume 1, while sipping their martini, wearing their ascot and having their shades on indoors? yeah. Nobody. You're gonna crank it to MACH 11 and rock out!
So that complaint is bogus to me. Also, if you correspond with the man; he'll tell you some people use step-down transformers or rheostats in-line to slow em down. He buys the fans from one of the largest fan suppliers in the world and has tested their db's. (So he says) he couldn't find a 120VAC fan out there quieter than the ones he uses. So take that for what it's worth.
Again, VERY nice guy to talk to. He'll go out of his way to get you what you need. Not many people like that these days. This is for the 400, but he makes them for the 700 too.
Yup, if I was to get a fan, that's the one I would get based on The Sniffs recommendations. When I read his thread I immediately looked them up.
Thing is, my amps don't even get warm. Most of the reason is I don't really crank them often, and if I do, they still don't get even moderately warm. Think it's because I use a active crossover for biamping, and don't feed each the entire media spectrum. I don't know, it's a bit of a mystery to me. Been meaning to pull the transistor covers and shoot them with the Infrared thermometer gun to see what the temps really are, just haven't got around to it. And I know the bias is correct, it's something I don't understand.
Think I figured it out. 400s and 700s basically have same "foot print", but 700s have appx twice the output. So 700s would run hotter and a fan would benefit them.
Been many a time I've wondered about pulling the silicone insulators and going with mica and good computer grade non conductive heat sink compound. Thought maybe the silicone insulators were not transferring the heat properly.