David's Phase Linear 700B Thread

Scary man, scary... 800 or so watts per channel, pair of D9's and a pair of Polk SDA's...

What could be better? ANOTHER pair of D9's... that would 'bout make my ears bleed... look at the meters man... barely registering

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Wow.. Youtube figured out that I took the vid standing on my head (upside down) and fixed it... that's cool!
 
Jerry: Nice clip! I hope the dining room with your fine China isn't in the adjoining room. It's hard not to get excited or as NavLinear would aptly say " I get hard when I'm excited!" I find even with Doug's PL 400, power is aplenty with hardly a nudge from the sweep indicators.

Nando.
 
That is seriously kickass Jer

* groan *

already thinking about looking around for a 700b though finding one on my budget would be a challenge LOL
 
Back Together Again

Well I finally got a weekend to fine tune the system after putting it all back together again. Joe; As always I am loving the light boards! After some dealing with my brother; I decided on the two Phase Linear 700B's I was going to use in my system. So these are some final cleaned up shots of my two-channel audio rack. I LOVE watching those needles bounce! Everyone MUST own a PL700. PERIOD. :thumbleft:


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A great looking system you have, David. Nice pictures.

Nando.
 
Beautiful system setup Dave. My lab amps are always in pieces on my lab bench so I never get to enjoy that type of scenery :-)
 
Thirded! Very VERY nice setup.. it was a shame I couldn't get over there, but those crazies I came with dragged me around from work .. to bar.. to work again... LOL.

Next time, definitely...
 
Thanks guys! I know its nothing compared to your audio racks. I've seen a few. Mine is less "studio" and more "home listening" as far as looks on the equipment in it's environment go. :-) some may recall my previous photo's in this thread of an entire rack of PL amps. Nothing else. With the source components sitting on top of that rack. In between the huge speakers. Back in those years, i wanted more SLAM less GLAM. Now older, I prefer the nice look of a simple audio rack next to the fireplace and the speakers on the other side of the room. So I can stand there with a beer in my finished basement, and enjoy the music. Same great slam, but now with the glam.

Jerry, its an invite man. Anytime you ever come round again, break away from those guys. Anybody can go to a bar. But only ONE person can get the chance to be at Davids house listening to the system. :-) So it's golden, next time your in town.

Joe, thanks for the many WOA conversions. I've enjoyed them immensely. I think in the last five months, my PL's spent more time on the bench than in the rack, so I know what you mean there. on my pics; thankfully, we don't use 35mm film anymore, cause I think I took about 25 photos to get that needle pinned down in the shot. :)

All I can say is; for anyone reading this thread who does NOT own a PL700 but has been considering it........ DO IT!!!! Then go see Joe. If you can't take on the task after that, consult with Lee and/or Jerry. You won't go wrong. I fact, just having one in its original state means your committed for life. Where you go from there, is up to you and the guys at Phoenix. Beautiful amps. Carver did it right with these things, and Joe did it better! ;-)

Thanks again guys!
 
Well I'll Be a Monkey.. and his Uncle too!

Dave....

Why it never manifested to where I could hear it here I'll never know, but... I do believe while replacing the RCA's and bypassing the pots I found the real cause of your hum. I was checking resistance to ground (making sure the new RCA's were isolated), and part of that is just a quick verification I had good ground on the chassis from the main star/cap ground.


Well, turns out... the chassis itself was NOT hooked up to the star ground, at ALL. Man it's the simple stuff one assumes to be there!! Basically the chassis was floating out there, catching any and all nasty stuff!

I figured I'd bring this up with ya, as we left this situation not quite "optimal" and you not benefiting from a full WOPL'd experience. Let me know if (perhaps) you might be interested in not only a WOPL'in but with the backplanes coming around the corner AND nice brand new caps in April you'll be getting on hell of an amp out of one of the others ya got!
 
It's been a while since that project. Some aspects of it are starting to fade. But somehow I seem to recall Joe mentioning that WITH the pots intact; going through the direct coupled/normal mode switch; that chasis ground WAS there by means of the switch contacting the chassis by its own hold down screws. Since we cut the factory solid wire that coupled the switch to the negative speaker binding posts, which in turn routed back to star ground .

As I left it; i believe the braided shields on the pots, both from the white oak board and the pots themselves, ran to the floating RCA bar. Then the floating RCA bar is connected to the direct switch. That switch is then grounded to the chasis by way of its hold down screws. Is this a proper grounding scheme when the white oak driver board is used in conjunction with existing pots? Cause I seemed to have been under the impression at the time that it was?

Cool to see tou still have that amp Jer. I thought you may have traded it a while ago for some new Jerry project? (Smiles). Right now as it stands; I no longer have three 700B's. I am down to just the two in their original state with only WOA light board conversions. I have been watching diligently the threads on the fully comp builds. I see Joe and Lee are still doing tweaks as the beta tests are proceding. Pending proper funds and final results of a few conversion projects; we will see to what level i may take my amps. You are correct in that I have four new caps on the way. Future investment stategery and all that ya know? ;-) a lot has changed so far since that project. I am still waiting on more news of being able to build brand new 700B's from scratch? Maybe I'll just start out with all new internals eh ? :-)

jbeckva said:
Dave....

Why it never manifested to where I could hear it here I'll never know, but... I do believe while replacing the RCA's and bypassing the pots I found the real cause of your hum. I was checking resistance to ground (making sure the new RCA's were isolated), and part of that is just a quick verification I had good ground on the chassis from the main star/cap ground.


Well, turns out... the chassis itself was NOT hooked up to the star ground, at ALL. Man it's the simple stuff one assumes to be there!! Basically the chassis was floating out there, catching any and all nasty stuff!

I figured I'd bring this up with ya, as we left this situation not quite "optimal" and you not benefiting from a full WOPL'd experience. Let me know if (perhaps) you might be interested in not only a WOPL'in but with the backplanes coming around the corner AND nice brand new caps in April you'll be getting on hell of an amp out of one of the others ya got!
Click to expand...
 
Even if the switch was grounded at one time or another, that is not how we ground the chassis. Instead, between the two main tie points and specifically held by the screw and nut combos is a white wire - that is not only supposed to go between the two tie points, but another wire should have been between the left tie point and cap/star ground. Single point ground to prevent any ground loops. I'd assumed it was in place, when it turns out it was not. In any case, I can definitely say there was a complete "open" between the chassis and star ground when I checked it last night and THAT was your issue with the hum... not a doubt in my mind.

In any case... No fear... when the backplanes become available it is THIS 700B that I plan on converting first. All goes well... you're welcome to try yourself or send one this way.
 
jbeckva said:
Even if the switch was grounded at one time or another, that is not how we ground the chassis. Instead, between the two main tie points and specifically held by the screw and nut combos is a white wire - that is not only supposed to go between the two tie points, but another wire should have been between the left tie point and cap/star ground. Single point ground to prevent any ground loops. I'd assumed it was in place, when it turns out it was not. In any case, I can definitely say there was a complete "open" between the chassis and star ground when I checked it last night and THAT was your issue with the hum... not a doubt in my mind.

In any case... No fear... when the backplanes become available it is THIS 700B that I plan on converting first. All goes well... you're welcome to try yourself or send one this way.
Click to expand...

Yes. I remember being told to cut that tie point on the right. The one that went between the right most back wall to the switch. Per instructions. (See pic of it in my very first post on this thread topic). But you are also right in that there was NO wire between the tie point to the LEFT back wall and star ground. I do believe I cut that too. I agree.

Hopefully; the backplane projects that are going on will be a huge leap forward. I look forward to also seeing how you make out with that 700B when you get backplanes. It's also my understanding that you are doing away with the pots entirely also? Are you also planning on re-routing your main AC line?
 
Ok, I know it's been a while; but question for you Lee. This 700B I just acquired......I opened her up and I see different color emitter resistors on the rails? Is THIS yet another "Mila Mod"?? Refresh my memory from last year......cause I thought all the original resistors were supposed to be the same value? I hope this doesn't explode on me?

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.33 on the positive, .27 on the negative is normal..
 
jbeckva said:
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... )

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DOH! :sign7: My fault Lee. If I re-read my own thread, it's obvious. Apologies. Ok.............I have a good candidate for a White Oaking in the future here. In the mean time....... I can't decide for now on blue or White? They both look fantastic. A comparo still makes it's tough...........

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