Phase Linear 3300 Series II Recap and Cleaning

laatsch55 said:
one little tip. To hold the faceplates vertical, take some 3" poly pipe , cut some 3-4" length pieces and slot the to fit the plate. that way they can be vertical and leave a lot more room to work the chassis.
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Thanks Lee for the nice words and your tip give me an idea. I'll let you know how it turns out.
 
speakerman1 said:
It is a PL. Lee and I went through this with my PL. I like the sound of mine w/o the mods. Not knocking the WO at all. I have never heard it. LOL Try going with some nice caps in the signal path. You can swap them to the WO mod. Just baby steps. When I bought the BGs they were a lot cheaper. There are some very nice caps out there. If you really want to go crazy. Read up on the Shotky diodes. Interesting reading. I was thinking of doing it but I didn't. Wonder if they can influence the sound? Since it is only going to be yours there are other tricks you can try before you swap. I'm an efficiency nut. Give them the least amount of work. Heat is bad. Are you coming out of a 120 volt power supply? Not the wall. My amps draw some power. If you can keep it stable and see what happens.
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Good advice Larry with the baby steps. I have the new WO controller board and LED board but I think the next change will be adding the dc protect board as I don't want to damage any speakers. I'll give it some more time before adding this board but we do want to practice safe audio. The LED board will follow and then we'll see what is next.

I've used Shotky diodes in work projects but have not done any research regarding this diode type and audio. A butt ton of reading awaits me.

Right now I'm using wall power as I'm still bench testing but the main reason is I don't have an isolation transformer - yet. I've used them for workand it does make a difference.
 
I did have a problem last night during my listening session - some audible pops that were fairly consistent. Since I'm running the 901's the EQ was between the pre and power amp and I have not opened this guy yet so it was the most likely suspect. I opened it up with the intent of cleaning and lubricating the two slider pots and the two switches and inspect the board for any obvious problems. Well - the board is single layer and the top side looked ok but when I flipped it over I could not believe how much flux residue was on the board. Photos to follow later this evening. In addition to the flux I counted at least four locations where the leads were excessively long and appeared to be touching the adjacent pad. Not good! I spent a couple of hours cleaning the board, trimming the excessive lead length and deoxing the pots/switches. I'll go over it at least one more time as the flux is a bitch to clean after all those years - 1992 date stamp on the board.

I put the system back together today and gave it a listen – the problem is now gone. I can’t believe the quality control missed something like this but it did.

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laatsch55 said:
All this in the Bose Equalizer??
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Yep. You can see one of the longer lead length components in the second photo. This wasn't the worst though. Someone bent it up before I took the shot so I had them move it back down to take the photo. The things one finds!

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Yeah - but it was an easy fix. I like easy - just had to spend a couple of hours cleaning and a snip here and there.

Damn it's hard to get a photo with the meters buried - especially when you're sideways and the faceplate is upside down. Sounds good though.

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Those 901's should be able to soak up all that 400 will put out.
 
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