David's Phase Linear 700B Thread

ksrigg

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#81
At last count

I currently have 2 700B's re-invented, and 5 400's (I did one myself). In the wings there is another 400 and two more 700B's. Those are the ones I want to get done. I THINK I can handle the 400. but the 700B's just scare me as I immediately ran into problems with that meter configuration. Joe tried his best and did explain what I need to do. I am just not competent and am afraid I'll blow something sky high. Is Mark still working on PL's? Hell, I may send them to you Lee, and you can put them in the stack, and get to them when you can.. I am certainly not in a hurry. I got plenty of WOPL power. I just want to get the other up and running cause they were meant to work. Not just sit on a bench for years. Plus Kev and I are going to finish a subwoofer for me (I've built him one, and many other people, I just don't own one, and it sucks cause I don't have FULL RANGE speakers like to smarter ones of the community. I have speaker pairs that could be full range, but they all need LOTS of time, labor, and calculations made to make them right. Subwoofer, and then finish the Klipsch rebuild....with or without adding volume to get more bass...AND NOW I HAVE TO HEAR THAT ALL THE PCB'S IN ALL MY AMPS ARE PRETTY MUCH OBSOLETE...MAN
 

Skratch

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#82
I currently have 2 700B's re-invented, and 5 400's (I did one myself). In the wings there is another 400 and two more 700B's. Those are the ones I want to get done. I THINK I can handle the 400. but the 700B's just scare me as I immediately ran into problems with that meter configuration. Joe tried his best and did explain what I need to do. I am just not competent and am afraid I'll blow something sky high. Is Mark still working on PL's? Hell, I may send them to you Lee, and you can put them in the stack, and get to them when you can.. I am certainly not in a hurry. I got plenty of WOPL power. I just want to get the other up and running cause they were meant to work. Not just sit on a bench for years. Plus Kev and I are going to finish a subwoofer for me (I've built him one, and many other people, I just don't own one, and it sucks cause I don't have FULL RANGE speakers like to smarter ones of the community. I have speaker pairs that could be full range, but they all need LOTS of time, labor, and calculations made to make them right. Subwoofer, and then finish the Klipsch rebuild....with or without adding volume to get more bass...AND NOW I HAVE TO HEAR THAT ALL THE PCB'S IN ALL MY AMPS ARE PRETTY MUCH OBSOLETE...MAN
Sutton, The only way you are going to learn is to jump into the fire. I learned by my mistakes and I am alot dumber than I used to be BUT I know what not to do. Double check what you do and you will suceed.
 

laatsch55

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#83
I currently have 2 700B's re-invented, and 5 400's (I did one myself). In the wings there is another 400 and two more 700B's. Those are the ones I want to get done. I THINK I can handle the 400. but the 700B's just scare me as I immediately ran into problems with that meter configuration. Joe tried his best and did explain what I need to do. I am just not competent and am afraid I'll blow something sky high. Is Mark still working on PL's? Hell, I may send them to you Lee, and you can put them in the stack, and get to them when you can.. I am certainly not in a hurry. I got plenty of WOPL power. I just want to get the other up and running cause they were meant to work. Not just sit on a bench for years. Plus Kev and I are going to finish a subwoofer for me (I've built him one, and many other people, I just don't own one, and it sucks cause I don't have FULL RANGE speakers like to smarter ones of the community. I have speaker pairs that could be full range, but they all need LOTS of time, labor, and calculations made to make them right. Subwoofer, and then finish the Klipsch rebuild....with or without adding volume to get more bass...AND NOW I HAVE TO HEAR THAT ALL THE PCB'S IN ALL MY AMPS ARE PRETTY MUCH OBSOLETE...MAN
They are not obsolete, unless you want to go complementary. Let me know when you want the cabbage cases sent your way....
 

Gepetto

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#85
They are not obsolete, unless you want to go complementary. Let me know when you want the cabbage cases sent your way....
. Not obsolete guys, I am working on latest innovation using the RevA board. I value very much bringing things to the next level based on customer input while at the same time enabling existing users to take advantage of new features.
 

jbeckva

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#88
Alrighty then...

Yeah wow... whatever this "mila mod" is all about, it's all gotta go. I have 100 ohm resistors going to places that just aint normal (not to mention they should be 10), both flavors of emitter resistors neither being .33's or .22's, and just.. weird.. heheh.

Anywhoo.. work has begun in earnest. Stripped off the positive side of the left channel so far, now time to open Lee's box of fun...

(pardon the blur... gotta go get the "good camera" in a few... )

DIGGIN IN.jpg
 

jbeckva

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#91
(mad phillipino mode on)

puck.jpg

Ey you 'puckin guyz! go 'puckin talk about boobies somewhere else!! you 'puckin pervs!!!

Lee.. yo... have ya really been able to suck all that solder off the speaker posts in order to get the standoffs screwed in???
 

laatsch55

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#92
Yeppers, got the worlds graetest solder sucker. Pulling vacuum on an AC condenser right now checking for leaks....
 

jbeckva

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#93
Hey Joe n Lee.. quick question ('less you're still getting booby bombed by Nav LOL...)...

This one does NOT have the resistors normally across the predrivers. I'm "used to" seeing and using 150's for those, but I think I am seeing in the 700B schematic 180 ohms? Should I stick with what I know here? Just thinking... with the PLWO board instead of the original, maybe you were designing with those being 150's on the chassis.
 
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#95
Alrighty then...

Yeah wow... whatever this "mila mod" is all about, it's all gotta go. I have 100 ohm resistors going to places that just aint normal (not to mention they should be 10), both flavors of emitter resistors neither being .33's or .22's, and just.. weird.. heheh.

Anywhoo.. work has begun in earnest. Stripped off the positive side of the left channel so far, now time to open Lee's box of fun...

(pardon the blur... gotta go get the "good camera" in a few... )

Good gravy? Why did they employ this Mila guy? It's a good thing he only lasted a few months? Not so lucky for ME tho? My poor amp. I hope she gets better. :)
 

NavLinear

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#96
Good gravy? Why did they employ this Mila guy? It's a good thing he only lasted a few months? Not so lucky for ME tho? My poor amp. I hope she gets better. :)
She will - maybe we can add some teats instead of knobs. I think this is a great idea myself. I'd post a photo but we want for this thread to stay in the DIY rather than the "dark and dungy area."
 
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#97
She will - maybe we can add some teats instead of knobs. I think this is a great idea myself. I'd post a photo but we want for this thread to stay in the DIY rather than the "dark and dungy area."
That's why we have "The Cave". I am becoming a regular visitor. The comments are hysterical and the photo's Nav....Well..........Aside from Phoenix, why would we need the internet for anything ELSE when we have "NAV'S AVATARS?" lol!
 

jbeckva

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#98
She will - maybe we can add some teats instead of knobs. I think this is a great idea myself. I'd post a photo but we want for this thread to stay in the DIY rather than the "dark and dungy area."
LOL.. you should incorporate that in your next batch of bias tranny brackets, Nav. Put a nipple on em... :tongue10:

Gotta run to the "shack" a little later today and get some 150's for the B-E's on the predrivers. Thought the ones on the backwall were, but they actually turned out to be something different when I put the meter to 'em..

Got the emitter resistors on the positive side almost done.. just double and triple checkin...
 

jbeckva

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Left channel's JUST about ready, but .. whoa did I find some issues on it. One of the two predrivers and ALL outputs except one were toast. Joe.. yes.. the other predriver on the positive side was short all the way around. Better take a very detailed looksee on the WO board to see if it was affected or not.

Anywhoo.. so this is what a 700's supposed to look like. We have the two 10 ohm biasing resistors in place, and the 150's B-E on the two predrivers. Big huge difference then when I started. Yeah... the diodes are cut and I'm going to replace them - I just couldn't believe that prelim checking between them yielded a flat zero (short) resistance and was thinking it could be them. Turned out for the best anyway tho in case they were damaged.

IMG_1671.jpg

Here's the other side with the new transistors installed.

IMG_1669.jpg
 
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