David's Phase Linear 700B Thread

Ok, your itching to see if the meter works so let's get that out of the way, then we can get serious. Button er back up. Check for meter operation, then grab that spare wiif ya got under the stairwell, hook up a pre-amp turn it on, see if you have hum out the woof.
 
Phase Linear Phanatic said:
Good point. Diode checks out. So where do we go from here? Put the face plate back on and hook it up? See if the meter works and we get hum after tightening? Or wait before I put the caps back in to be clear on the bolts thing?
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Yeah I lifted that diode while trying to see if it was the cause of the meter being dead.
 
laatsch55 said:
Joie is more qualified to explain the bolt thing. If you could make 3 turns , it needed tightening. Did you replace the RCA jacks?
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Audible vibration is why to tighten, laminations and bolts will vibrate in the presence of the magnetic field in the transformer core.

In reality those bolts should have been insulated by Phase Linear from the stack but they never have been throughout Phase production. Without insulating, you get eddy current losses in the screws and stack. Maybe they did not know this??
 
laatsch55 said:
Ok, your itching to see if the meter works so let's get that out of the way, then we can get serious. Button er back up. Check for meter operation, then grab that spare wiif ya got under the stairwell, hook up a pre-amp turn it on, see if you have hum out the woof.
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Well as you suggested Lee; I am taking photo's of EVERY step I take here. No matter how small. Good thing I have a great camera. Okay, Just put the faceplate back up, and hooked up the right channel to one of my spare woofs. HUM! :-( Nothing else connected. Not even the pre-amp. Just the 700B to the woof. Well.........next I ran a patch cord extension from my rotel preamp over to the PL to test the meter. And Hazaa! The meter bounces.

So................We are still back to square one on Mr. Hum dinger.............:banghead:

IMG_0023.jpgIMG_0024.jpgIMG_0025.jpgIMG_0026.jpg
 
NO!!! Either short the RCA jacks or plug in a working pre-amp. You will always get noise with the RCA's left empty...
 
BTW, on my bolts request; I robbed the bolts from my PL 200 to use them on the PL 700B. So that's taken care of. The PL 200 is shoved into a wood cabinet and has little clip angles screwed in the back to keep the amp from sliding backwards in the cabinet. This ensures a tight fit against the inner cabinet wall, so yeah there are holes, but the faceplate isn't just gonna fall off. :toothy10:
 
OK after checking that, unhook Don's board. Take the output rail wires loose and then directly to the speaker. We are eliminating any influence Don's board may have on it. The output wires and the output grounds.
 
You never di say if you wanted the bolts for sure or not, so I didn't send em. Got a bunch here.
 
laatsch55 said:
NO!!! Either short the RCA jacks or plug in a working pre-amp. You will always get noise with the RCA's left empty...
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How so? I did it both ways? The noise doesn't suddenly dissapear when I connect RCA's to the amp? As I just stated, I ran a patch cable over to the amp from my system and had music playing from the woofer. You can see the needle working in my photo. Before I turned up the pot to get the music going, I STILL had the same hum. (with the RCA's connected). So Preamp connected or not; it doesn't change the problem I am having...................
 
laatsch55 said:
You never di say if you wanted the bolts for sure or not, so I didn't send em. Got a bunch here.
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I think in this thread somewhere you mentioned sending them to me with the grounding lug I was seeking for the PL 2000. But it stopped there. I wasn't gonna ask again cause I don't wanna look a gift horse in the mouth and all? You know what I mean?:happy4:
 
Phase Linear Phanatic said:
I think in this thread somewhere you mentioned sending them to me with the grounding lug I was seeking for the PL 2000. But it stopped there. I wasn't gonna ask again cause I don't wanna look a gift horse in the mouth and all? You know what I mean?:happy4:
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Gotcha,.
 
laatsch55 said:
OK after checking that, unhook Don's board. Take the output rail wires loose and then directly to the speaker. We are eliminating any influence Don's board may have on it. The output wires and the output grounds.
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Okay. Really, REALLY dumb it down for me. Which wires do I need to leave in and which wires to I hook the + and - of the woofer to? Yes I AM that much of a simpleton. I REALLY don't want to screw anything up here....................

IMG_0033.jpg
 
Phase Linear Phanatic said:
Curious? Regarding.............................................................................
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A number of things, but some of it was dedicated to the 2 prong/3prong thing. THE ONLY 3 prong plugs Phase installed were for export--the dual voltage to everywhere but Canada, the sing;le voltage to Canada. Turning a 2 prong plug over and plugging it back in will sometimes help with hum issues. He has done a lot of research into "leakage Losses" to ground. When he rounds up his papers we'll post em.
 
The top white and grey are left channel +/- in that order. The red and grey are right channel+/- respectively.
 
I see you have the AC feeds for Don's board wire tied to the output wires, separate those. And the white wire between those AC sources, where does that go??
 
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