phase linear 400

ABebar said:
At the time that I was running the ground wire I was thinking it paired with the DC. Then the next step had me running the AC wire and I didn't think much of it. I just mounted the DCP board and terminated the connections for the first time last night and got a better feel for how it works.
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The DCP ground is paired with DC, NOT AC
 
WOPL Sniffer said:
Gene, Joe is Gepetto here on the site and he's the reason most of us are here on this site keeping the Phase Linears alive and he supplies us with all the upgrade parts (He's White Oak Audio). Get out the credit card and finish buying the upgrade parts so that 40 year old amp quits fuckin with your brain (It will blow again, it's just a matter of weeks). :)

CHER????


HUH?
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yes, i knew that joe was gepetto....i understand he is the whiz kid of the phase linear legendary accomplishments....i sincerely appreciate all of his wisdom he has generously shared with me....and i knew also he was mr. oak, white oak that is....
for now, i dont think i want to upgrade this 400....i think i want to keep this one stock ... i did get joes light BOARD kit, and the power supply upgrade capacitor kit...and the dc protect board...so i dont burn down the barn, so to speak...i want this as a token of the sound i fell in love with in the early to mid 70s.. with safety compensated for with the upgrades....
i think i want to upgrade a 700b or possibly another 400 ....i asked the group about a cheap one i found...but, was advised to not get a 4 fin...i will pick up the search when i finish with this one...or find a deal i cant pass up.....i have a few spare parts i have accumulated...but, i was told there are great similarities in the two lines of phase linear...
CHER...joe is a first name and no last name....as cher has one first name and no last name...that was an attempt at ironical satire...i must have failed...lol
i do appreciate your help and advice!!!
thanks to all
 
There is one more thing I was curious about... I thought I was being smart but now I'm thinking that I might be making more trouble for myself in the very near future.

I am currently leaving out the middle heat sinks so that I have better access to the transistor mounting holes. It's really easy when you have clear access. My plan was to continue to bring up the amp back plane one row at a time until they were all in, then temporarily remove those four screws threaded into the standoffs and mount the heat sinks back in. I thought I was being smart and dealing with the four standoffs would be easier than fishing 16 transistors into a narrow space one at a time. Now I'm thinking that lack of access to the standoffs behind the backplane board might make it impossible to lock these screws back in without direct access. Perhaps I could thread a screw in from the top while I back the screw out the bottom to hold it in place, then do the reverse after the heat sink is installed? Has anyone tried this before? I would hate to get all four rows in and then realize that I need to pull them back out to install the two little heat sinks, but I'm starting to think that's exactly what is going to happen.

Any thoughts?
 
Fight the good fight and dont mess with the heatsinks..
 
Those heatsinks are either bonded or glued somehow. Every set I've taken off are really stuck and you may compromise heat transfer more than it is already..
 
ABebar said:
There is one more thing I was curious about... I thought I was being smart but now I'm thinking that I might be making more trouble for myself in the very near future.

I am currently leaving out the middle heat sinks so that I have better access to the transistor mounting holes. It's really easy when you have clear access. My plan was to continue to bring up the amp back plane one row at a time until they were all in, then temporarily remove those four screws threaded into the standoffs and mount the heat sinks back in. I thought I was being smart and dealing with the four standoffs would be easier than fishing 16 transistors into a narrow space one at a time. Now I'm thinking that lack of access to the standoffs behind the backplane board might make it impossible to lock these screws back in without direct access. Perhaps I could thread a screw in from the top while I back the screw out the bottom to hold it in place, then do the reverse after the heat sink is installed? Has anyone tried this before? I would hate to get all four rows in and then realize that I need to pull them back out to install the two little heat sinks, but I'm starting to think that's exactly what is going to happen.

Any thoughts?
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or, use the telescoping magnet output installer and be done with it
 
laatsch55 said:
Those heatsinks are either bonded or glued somehow. Every set I've taken off are really stuck and you may compromise heat transfer more than it is already..
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Hmmm... These came off really easily. They weren't bonded together at all except for some old heat sink compound. The heat sinks are basically four separate pieces of rolled steel formed into two different pairs of "U" shapes. When I pulled the old transistors out the heat sinks came apart from the chassis. I was able to wash and dry them separately and then reinstall the two larger outside ones, but I left the two smaller ones (between columns 1/2 and 3/4) removed.

Attached is a pic from when I first fitted in the back plane boards with the two larger heat sinks installed. The two smaller ones are somewhat visible in the lower left-hand corner next to the faceplate.
 

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WOPL Sniffer said:
or, use the telescoping magnet output installer and be done with it
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I thought I found a shortcut. I should have known it was too good to be true. I have heard fishing these in is a bit of a headache and I thought I discovered a workaround. I'll revert back to the traditional way. Thanks for the feedback.
 
laatsch55 said:
Those heatsinks are either bonded or glued somehow. Every set I've taken off are really stuck and you may compromise heat transfer more than it is already..
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Correct Lee, they are glued together with thermal glue...Adam I have no idea what you have there...other than to use Perry's term. Huh??
 
:-/

I suppose my question has changed then... When I put these back together, should I do anything to increase the thermal transfer? I suppose I'll reapply some heat sink compound, but it really is just those two screws holding the small U heat sinks in place.
 
ABebar said:
Hmmm... These came off really easily. They weren't bonded together at all except for some old heat sink compound. The heat sinks are basically four separate pieces of rolled steel formed into two different pairs of "U" shapes. When I pulled the old transistors out the heat sinks came apart from the chassis. I was able to wash and dry them separately and then reinstall the two larger outside ones, but I left the two smaller ones (between columns 1/2 and 3/4) removed.

Attached is a pic from when I first fitted in the back plane boards with the two larger heat sinks installed. The two smaller ones are somewhat visible in the lower left-hand corner next to the faceplate.
Click to expand...
2" diameter bulk caps???
 
ABebar said:
:-/

I suppose my question has changed then... When I put these back together, should I do anything to increase the thermal transfer? I suppose I'll reapply some heat sink compound, but it really is just those two screws holding the small U heat sinks in place.
Click to expand...

Yes and yes...
 
ABebar said:
I thought I found a shortcut. I should have known it was too good to be true. I have heard fishing these in is a bit of a headache and I thought I discovered a workaround. I'll revert back to the traditional way. Thanks for the feedback.
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After years of the guys on these pages coming up with procedures for upgrading or just repairing these amps, all of these "Shortcuts" "New Ideas" have all been explored with varying degrees of success. Use the traditional (Normally used) methods and go for it. Just a tip, tie up all those wires or you'll be chasing broken solder joints by the bushel. There is safety in numbers and I always tie my wires to prevent damage. Building these amps may look easy but it aint and when you are finished, the bad practices stand out like a broken pecker. Clean clean clean, tie tie tie etc.....
 
I'm anal.... I go through hundreds of zip ties and I may put 10 ties on, reroute one wire, and cut the ties all off, and then tie them up again (MANY TIMES). Nothing worse than a wad of wires you can't look at and trace if needed and puts the pro touch to it.
 
WOPL Sniffer said:
I'm anal.... I go through hundreds of zip ties and I may put 10 ties on, reroute one wire, and cut the ties all off, and then tie them up again (MANY TIMES). Nothing worse than a wad of wires you can't look at and trace if needed and puts the pro touch to it.
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it does look nice...
 

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I have the serial number written down as 7A11091

Whoops, wrong one, that was from a 700s2. The 400 serial number is 17056.
 
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