Cory's Phase Linear 2000 Ser II Restoration

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calman46

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I think I'm mixing up the terminology.I'm not going to connected right to the chassis. I'm looking at R65 ,R57 ,R36 all go to ground I was going to use this ground connection.
 
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calman46

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Putting caps on #7 &#11(Brown dog IC) didn't stop the howl. I put the original IC back in . I replaced the back to back signal path caps with 5.1uf Dayton film caps . Test listen with bench stereo and the sounds is more detailed. I still have the hum though ,I'm re-flowing more solder joints .
 

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I don't notice the big silver shield platethat shields the pushbutton assembly?? Did yours come with that??
 
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calman46 said:
Putting caps on #7 &#11(Brown dog IC) didn't stop the howl. I put the original IC back in . I replaced the back to back signal path caps with 5.1uf Dayton film caps . Test listen with bench stereo and the sounds is more detailed. I still have the hum though ,I'm re-flowing more solder joints .
Click to expand...
Those are some mighty large caps :)
 
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calman46

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I put that metal shielding back in it didn't help. Tapping on the face plate comes through the speakers? Is this a ground problem ? I think those caps will sound great if I get rid of the hum and hook it to a better setup .
 
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calman46 said:
I put that metal shielding back in it didn't help. Tapping on the face plate comes through the speakers? Is this a ground problem ? I think those caps will sound great if I get rid of the hum and hook it to a better setup .
Click to expand...
Is the AC inlet side stock? 2 wire cord? Can you provide some close ups of what is going on there? Is the hum 60Hz type hum?
 
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calman46 said:
I put that metal shielding back in it didn't help. Tapping on the face plate comes through the speakers? Is this a ground problem ? I think those caps will sound great if I get rid of the hum and hook it to a better setup .
Click to expand...
Is there one and only one connection to chassis from the analog ground on the board?
 
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calman46

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I'll check the analog ground you mention .Here is a picture of the AC sockets. It started as just a low level hum but touching the unit now makes louder .
 

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calman46

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It's the handles ,they connect the face plate to the black chassis (ground?) .It's quiet now and sounds great . I'll play on a better setup tomorrow. I think I'll keep the orignal IC in I don't like that howl Thanks guys
 
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calman if you have sockets installed for the IC's try that howler one more time....
 
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calman46

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It still howls . I had removed the 20NF caps from the IC's power pins but I don't think that matters with this . It only howls with the pre amp off and the amp on as we know. When it was howling I unplugged the turned off preamp from the wall AC and the howling stopped. Its sounds like the amp is picking up the 60Hz from the preamp's AC line when the preamp is off .
 
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calman46 said:
It still howls . I had removed the 20NF caps from the IC's power pins but I don't think that matters with this . It only howls with the pre amp off and the amp on as we know. When it was howling I unplugged the turned off preamp from the wall AC and the howling stopped. Its sounds like the amp is picking up the 60Hz from the preamp's AC line when the preamp is off .
Click to expand...
Are you back to the OP2134? Or is it doing it now with the RC4136 installed?

Is your power amp a 3 prong or 2 prong AC feed?
 
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calman46

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2 prong and I have OP2134 in. I tried plug both ways . How are the preamps's outputs working with the unit off? Maybe I will email Brown dog .
 
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calman those output coupling caps could run that re-amp for minutes. Get shorting RCA's for the phono circuit if the original RCA's were relaced. Look in the RCA jack, the grounding prong should come to rest on the signal prong inside the jack. Getin there with some Q-tips and clean every contact inside those jacks. They cause a lot of problems. Please answer this post of Joe's, he was on to something....






Is the AC inlet side stock? 2 wire cord? Can you provide some close ups of what is going on there? Is the hum 60Hz type hum?
 
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calman46

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It howled with the back to back electrolytic caps also . I posted a picture of the back side of AC connections in Post 71 . It looks to be an orignal 2 wire cord .Not sure I know what you mean by"side stock". When I came home I turned on the amp and just plugged in the preamp and it howled . The pre was off all day so the caps should have discharged .We have 2 unanswered questions, 1. Why doesn't it howl with the orignal RC4136 in ? and 2.Why does it stop howling with the OP2134 when the preamp is turned on ? It appears when not powered the OP2134 acts differently from the RC4136 . The jacks are cleaned there was some stubborn tarnish on the shorting pin but I scraped it off . HOwl is not a real good description its more of a hum (60Hz? )
 
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calman46 said:
2 prong and I have OP2134 in. I tried plug both ways . How are the preamps's outputs working with the unit off? Maybe I will email Brown dog .
Click to expand...
Brown Dog won't be able to tell you squat about the 2134 innards, they just make adapter boards.

The preamp outputs are NOT working, they just provide an input sneak path of some sort to ground or some other signal path. Have you unplugged all the inputs to the preamp to see if it howls while off but with nothing connected to the input of the preamp?
 
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