David's Phase Linear 700B Thread

jbeckva said:
I think you misunderstood me a little. I went into my mod work with my 700's already ripping the switch out because I'm going to keep it in DC mode and any superfluous (again, only to me alone knowing what I am going to do with it) circuitry like the switch would be bypassed - my own "purist" approach on a unit that was mine to work on and I listen to daily. The switch was gone even before completing the build and testing it. I had hum and ground issues even with it out of the circuit, for which both grounding analysis AND taking into account the level controls (again, make sure they are NOT wired with the wiper adjusting the input side) was how it was overcome. Now the "3rd extreme" is to bypass the level controls altogether, but even I haven't been quite sold on that concept.. but that to me is also an option - to discuss and not assume, if you catch my drift.

If I was working on a unit from another owner, and they specified the switch to stay in and function as it should, well there wouldn't be any argument past one quick "Are you sure?" question, explaining the pro's and con's. After all, it's not my amp to make that decision. :toothy10:
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I guess I am not quite the purist as you guys are? And by purist I mean, carving a Linear up to the point that without an anechoic chamber you couldn't hear any noise at zero volume. For ME; no audible HUM with my face 6 inches from the woofer in dead silence, is good enough. I am not trying to get the noise floor so low that only a super trained ear or test equipment will pick it up? (I lost my hearing YEARS ago to heavy metal concerts boys).

Okay. Bottom line. Before I send anything anywhere; and bother those who are busy with other work; this is what I need.
.The fuses blowing issue fixed foremost
.The Mila Work reversed and upgraded. Emitter resistors; new diode's where applicable..... everything.
.NEW transistors in the back to replace my tired 1B05's
.A Don DC circuit protect board if needed

And NO mods to the pots, -20db switch or normal/coupled switch. I want the amp to function as intended. Just the ground problem cleared up. After all that, Joe's boards are in there and take over what was left to mod. New bulk caps and rectifier, with new RCA's I did already. (Which my handiwork MAY be part of the problem) :confused3:

So that's it. And of course I pay for shipping. It's sitting right here next to me ready to go all boxed up. Just need the ok and approval from you Jerry. Your time is incredibly appreciated! Lee, if Jer want's the task, that's generous of you to send him the transistors and Don board. Much thanks in advance! Let's see If I can get the amp from hell figured out!
 
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Dave, that is not the amp from hell, that distinction belongs to Gibsonians " Cathy"---THAT IS THE BITCH AMP FROM HELL. Just because I may like my amps a certain way does not mean I push that on a customers amp. Two different worlds. Remember, if an amp does "quiet" well, you can bet it does a lot of other things well too. Kinda like the mountain thing, you climb it cause it's there, same with Joe, there's still noise....
 
"And NO mods to the pots, -20db switch or normal/coupled switch. I want the amp to function as intended"



Better De-White Oak it then, that's like being " a little pregnant"
 
Built any of these yet Dave???
 

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laatsch55 said:
"And NO mods to the pots, -20db switch or normal/coupled switch. I want the amp to function as intended"



Better De-White Oak it then, that's like being " a little pregnant"
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Okay. "TO AN EXTENT". I would think simply replacing 40 year old parts IS and upgrade, but the amp can still sound only better with those parts. Upgrading an existing part is one thing; deleting it is another. At least to me. No quams about the act of doing so, only helping matters. That's up to the perspective customer. I DO understand that. I just didn't KNOW my amp was so deficient? Thanks to Joe, and Phoenix, how would I? Phase Linear Phanatic is Phanatical about Phase Linear's. True. But to the point where he is modding his own amps? errrrr......... I suppose that's where I slipped up? I probably shouldn't be throwing stones because after all, iiiiiiii am the one who needs BOLTS instead of rack handles remember? So "technically" I am defacing it already. Sorry for the misunderstanding if any? It's hard to convey over a computer sometimes. This is why I am a :newb: or a :knob:. Whichever you prefer..........
 
laatsch55 said:
Built any of these yet Dave???
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No I have not Lee. But I HAVE seen one similar to that on the back of a PL amp on ebay once? I always wanted a dual fan like that! One for each of my B's. I assume they are whisper quiet? I have just the one original Phase Linear PL700B fan on the back of the one that controls my bass. (The now currently dead one). And it's a single fan. Nice work! Those look neat!
 
They take an hour to build is all and they "Snap On". Got some green ground clips that sit and snap on the top then bring the bottom in and it snaps onto the backside of the heatsinks. We phanatics were brainstorming one weekend and these are what we came up with. Some 1' by 1/16 aluminum angle, and some 3/4 of same and they fall together. To get 2 to fit the back of a 700 it takes 2-4-5/8 fans.


No problem on the misunderstandings, hard to interpret finger tone and lilt....
 
Don't need whisper quiet fans when ya need fans.......................
 
laatsch55 said:
Dave, do you have the RCA-410's as drivers??
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Lee, I honestly do not remember? Do they SAY 410 on them? They ARE RCA's. I know that for certain. But the amp is cradled up in a box ready for shipping now. So I can't check? I know all they said on them at the bottom (and I assume the bottom four across the fins are the driver transistors) was the date code in 1966, and 1B05. I THINK. That's all I know. Why may I ask? Is that a good or bad thing?
 
laatsch55 said:
Don't need whisper quiet fans when ya need fans.......................
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Wow. How true? I can hear my Phase Linear issued fan running. So that's why I said it? Look at me? All worried about noise when I am the one sayin "nawwww forget about that SNR"! LOL!
 
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laatsch55 said:
They take an hour to build is all and they "Snap On". Got some green ground clips that sit and snap on the top then bring the bottom in and it snaps onto the backside of the heatsinks. We phanatics were brainstorming one weekend and these are what we came up with. Some 1' by 1/16 aluminum angle, and some 3/4 of same and they fall together. To get 2 to fit the back of a 700 it takes 2-4-5/8 fans.


No problem on the misunderstandings, hard to interpret finger tone and lilt....
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Does that shiny aluminum come in black? May have to order me a few. :grin:
 
Just curious on the 410's is all. They are our preffered driver. If they aren't I'll ship Jer some of those too.


Joe, the SNR is still there, at my listening levels I think that is defined as undiscernable background!!
 
Ok, sounds like it's a "go" folks! Good deal. Dave you have my addy, right?

(coming up for air here before I finally get to get some damn sleep.. work is a beeeeotch... :sad2::banghead::confused3:)

Gnight!
 
jbeckva said:
Ok, sounds like it's a "go" folks! Good deal. Dave you have my addy, right?

(coming up for air here before I finally get to get some damn sleep.. work is a beeeeotch... :sad2::banghead::confused3:)

Gnight!
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Jer, sending the amp your way, first thing in the morning. From there, as far as parts go, i will let you and Lee work that out. You guys know what's best. Obviously Mila didn't. Lol!! Going to bed. Night guys.

Oh and by the way; my avatar. The top two amps I am selling. The bottom one is my treble driver and the second from bottom is my "trouble" amp Jer is getting. Good luck man.
 
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OK Jer, we got a 700DCP--(re-zoebeled), 10-.27's, 10-.33's 4 standoffs, 20 MJ21196's and 2 of FaboNav's latest, greatest bias Transistor brackets....
 

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Jer, if he was foolish enough to send the rack handles..........um.........lost in shipping?????
 
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