Author Topic: Phase Linear 400 Refurbishing Project  (Read 15482 times)

OldiesButGoodies

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Phase Linear 400 Refurbishing Project
« on: June 04, 2016, 08:30:08 PM »
Creating a thread to store pictures from my slowly unfolding Phase Linear 400 refurb. 

As purchased:

Untitled by Jose Sifontes, on Flickr

One of the power supply can caps was shorted so I replaced them with a slightly higher value and voltage set of caps (from 5900 uf to 6800 uf):

Untitled by Jose Sifontes, on Flickr

The new cans are smaller and do not use screw terminals,  so had to use a rubber spacer to retain the original mount and adapt O terminals so the original Phase Linear wiring was not affected:

Untitled by Jose Sifontes, on Flickr

Also added bypass caps per OCCD's suggestion:

Untitled by Jose Sifontes, on Flickr

I bought all the caps to redo the driver board:

Untitled by Jose Sifontes, on Flickr

But it sounds so good as-is that I am thinking of not doing anything to that board for now (if not broken,  don't fix it..)

Next is the install of the blue-LED mod  and the speaker protection relays (neither has arrived).   And finding a Phase Linear 2000 to pair it up with. 

Will post pics after that as well. 

 :)

OBG


« Last Edit: June 04, 2016, 09:27:44 PM by OldiesButGoodies »

Offline F1nut

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Re: Phase Linear 400 Refurbishing Project
« Reply #1 on: June 04, 2016, 09:09:57 PM »
Looks fine so far. I like the wood cabinet.

I'm sure you meant 5900uF, right?
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OldiesButGoodies

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Re: Phase Linear 400 Refurbishing Project
« Reply #2 on: June 04, 2016, 09:28:43 PM »
Looks fine so far. I like the wood cabinet.

I'm sure you meant 5900uF, right?

Yes! corrected that typo...  Thanks for the + feedback Jesse.

Reg,

OBG

Offline Kingman

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Re: Phase Linear 400 Refurbishing Project
« Reply #3 on: June 05, 2016, 05:51:48 AM »
What led you to try a Phase Linear Pepe?
IN REALITY IT ONLY MATTERS WHAT IT SOUNDS LIKE TO YOU!!!!!

OldiesButGoodies

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Re: Phase Linear 400 Refurbishing Project
« Reply #4 on: June 05, 2016, 09:34:40 AM »
This Phase Linear 400 showed up on Clist locally at a good price,  so I snatched it.  I want to have a second system so I thought I could use this as the starting point. Never owned a pre-Carver Carver product and I liked the fact that it came with a wood case in good shape.  Happy so far - just afraid to use it with the big speakers until the relay is installed!

Offline Kingman

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Re: Phase Linear 400 Refurbishing Project
« Reply #5 on: June 05, 2016, 09:51:22 AM »
I'm listening to my Dual 500 right now...they are great amps and the bad rap they have acquired is undeserved...most were ran in professional applications and abused to the max!
IN REALITY IT ONLY MATTERS WHAT IT SOUNDS LIKE TO YOU!!!!!

Offline papabearjew

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Re: Phase Linear 400 Refurbishing Project
« Reply #6 on: June 06, 2016, 01:17:27 AM »
One mod you should do that was never done to mine is the speaker protection mod like White Oak offers. Every time I shut it off I held my breath for the very loud shut down thump that went through your speakers. I think that mod also protects your speakers from the straight DC issue they're known for. I still have to have my PL400 looked at to see what damage I caused to it. You may want to look online and see some photos of it with the blue LEDs. I like the natural color that they came with better. It keeps with the  vintage heritage of the amp. They do offer LEDs in natural colors. My opinion of course.

OldiesButGoodies

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Re: Phase Linear 400 Refurbishing Project
« Reply #7 on: June 06, 2016, 08:44:33 AM »
Hey PBJ -

I did look at the Oak Audio mod for speaker protection,  but found it a bit expensive at 100 for what is essentially a uPC1237 chip and some relays,  so I ordered it separately on ebay for a lot less (1/10th the price) and I am going with that.   Did notice a bit of a thump on shut off,  not too bad (I have heard much worse - I am looking at you, Melos equipment) and thought it would be taken care of by a ceramic cap by the power feed but not sure yet.  Come to think of it I could use the relays controlled by the 1237 for that as well,  just need to think it through a bit. 

On the meters - I ordered the blue LED kit.  Guilty,   I like the blue light (and I can barely see the needles dancing with the original lights).  I am trying my best to do everything in such a way that a future owner concerned with originality can reverse my work,  so along with the old can caps I will store the existing lighting board so it can be swapped back in.   

As I mentioned earlier,  I am surprised at how good this amp sounds for being a "budget audiophile amp" of the early seventies.

OBG
« Last Edit: June 06, 2016, 08:46:22 AM by OldiesButGoodies »

Offline papabearjew

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Re: Phase Linear 400 Refurbishing Project
« Reply #8 on: June 07, 2016, 12:47:18 AM »
OBG sounds good

Offline F1nut

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Re: Phase Linear 400 Refurbishing Project
« Reply #9 on: June 07, 2016, 01:26:49 AM »
  'Political Correctness'.........defined

"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
 

Offline Kingman

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Re: Phase Linear 400 Refurbishing Project
« Reply #10 on: June 07, 2016, 09:05:04 AM »
IN REALITY IT ONLY MATTERS WHAT IT SOUNDS LIKE TO YOU!!!!!

OldiesButGoodies

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Re: Phase Linear 400 Refurbishing Project
« Reply #11 on: June 07, 2016, 05:28:24 PM »
And now I also have the Phase Linear 2000 pre to pair it up with...  Wil start working on the blue LED mod tonight. :P

OldiesButGoodies

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Re: Phase Linear 400 Refurbishing Project
« Reply #12 on: June 07, 2016, 09:34:24 PM »
This is an absurdly easy mod if you buy the kit from Oak Audio - very well done:

Before:

Untitled by Jose Sifontes, on Flickr

Boards side by side:

Untitled by Jose Sifontes, on Flickr

Installed:

Untitled by Jose Sifontes, on Flickr

And lit up:

Untitled by Jose Sifontes, on Flickr

I like the look.   :'(

OBG
« Last Edit: June 08, 2016, 09:45:43 AM by OldiesButGoodies »

Offline MacGeek

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Re: Phase Linear 400 Refurbishing Project
« Reply #13 on: June 08, 2016, 05:33:28 AM »
Looking good.  There is just something about big blue meters.............
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OldiesButGoodies

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Re: Phase Linear 400 Refurbishing Project
« Reply #14 on: June 14, 2016, 04:05:26 PM »
Minor mishap last night while recapping the control board - blew one of the fuses in search of a 12V signal (this thing has 80V all over the place) and the %$%$# fuse is that strange AGX size.  Instead of searching for a new fuse I am installing a regular size fuse holder and going on with life.   ::)

Untitled by Jose Sifontes, on Flickr