Kevin's "I Want a Phase Linear 700 B White Oaked" thread

[soundude]

That was a shorted transistor? Looks like its been burning for a while...Like to see the speakers it was connected to...lol

 

[laatsch55]

Joe----absolutely!!
John---Fuses were correct, They did not have Mica, they had thermafilm, a substantially inferior heat transfer product.

 

[soundude]

You mean the infimus sillpads...i made sure I changed mine all to micas afer the 909 change out.
Is there sillpads between the sockets and the chassis too?

 

[soundude]

I dont know Lee lotta contact cleaner and solder your gonna need...may the force be wih you..
send progression pics...

 

[laatsch55]

No, Thermafilm is a thin, plastic film that still requires grease, but it does everything that mica does.....only worse.

John the damage on the board and chassis wall was not the result of a shorted output. The common point for the emitter resistors shorted to the common of C22, C23 and R53. this affected the ground reference for the input pair and the low voltage source.

had i known more when testing it , I could have understood why it appeared this channel was chasing it's tail. It never appeared "settled" always agitated.

The " open " output was more likely the result of the mechanically induced short on the board.

 

[laatsch55]

Amen John, but that's what I'm good at. My tolerance for repitition is high, can be selectively OCD when required, and ain't no wire or semiconductor is gonna get the better of me.......well.../.....not for long anyway!!

 

[mlucitt]

Lee, it also looked like there was no grease under the devices, just between the Thermafilm and the heatsink. Is that right?

 

[laatsch55]

Correct Mark. Very observant.

 

[laatsch55]

Am I the only one excited about a truly compatible replacement knob???????????????

 

[Gepetto]

I guess we are speechless Lee

Are those knobs orderable somewhere? One of my 700 knobs has a small dent in them.

Are the knobs billet machined or the spun aluminum over plastic?

 

[laatsch55]

Billett machined, approx same OD. Same bore, same size set screw. Came in Larrt's SP-12 kit.

 

[soundude]

I know that number....thats a antique electronics number....I get parts from them for my tube amp projects....
http://www.tubesandmore.com/

 

[soundude]

Lee/Joe, it's great that you have patience for that...I do with my tube projects because I understand the circuits and simple for me but when it comes to transistor circuits it gets to become a hair puller chasing problems because I don't have test equiptment for it...tubes are just resistors and a few caps thats it..don't need fancy scopes and testers, signal generators. Tubes all you need is a DVM...I even use a simpson analog and a tubed volt meter....
Lee I read the post I commend you on a fine job, I wouldnt have done as much as you have done with the scope and loading, I would have changed everything then did all that.
I also must admit the 700 really does have a fabulous sound...tons of bottom in the direct mode and really extensive highs..mine seems to be working great. Havent done the higher load test just enjoying it, I didn't even put together yet...Joe, I and probably everyone else who got white oaked considers you the PL God and bows to you for all the hard work and engineering of your board.
I for one praise and bow to you, thank you..I will be emailing you for the light kit soon, as soon as I can get my ass from the listening chair.

 

[laatsch55]

Ah.....another one smitten with massive amounts of clean power. My K's get awfully loud around 400 watts.

 

[laatsch55]

John, the original PL boards were not all that great in the bottom end. When Joe got done modeling the improved freq response he e-mailed me with the recommended changes saying " Thought you might be interested" yeah you could say I was interested. Up to that point my Modded Spec 2's were the alpha dogs around here, after another 30 minutes on that board, they are pulling back up duty. I bought a Bryston B4 just to do a head to head comparison, not even close. Bob had a lot of things right in 1969, think about that-----43 years of technical tsunamis and MAYBE after Joe's board you could find something that sounds better. Granted hearing of music is probably the most subjective field of interpretation we have(other than sex). But, Bob had a lot of things right. Joe, through his work and then his passion for music has morphed it to where it is now. It got to you too.

 

[laatsch55]

Thanks for the link John, found em in 2 minutes, got 8 coming.

BTW, I have 3 versions of a Simpson 260, one was my Dad's, and 2 others from people who meant a lot to me.

 

[soundude]

Awesome Lee, glad you found the knobs.
I'm listening to this PL700 now and I don't think its ability to be improved any further exists...its got all the greatest stuff now. Except Joes light Kit. Unless Joe thinks of another fabulous board, I cant think of anything to make it better.. Cosmetics possibly but not much...the chassis could use some strengthing for that transformer...
You got something there, how about sound interpetation and sex as a comparison together...LMAO!
I'm glad you guy's guided me through this, very impressed with the sound of this amp...think its time to add it to my list of great performers.
Somebody needs to design a shallow shroud with a quiet muffin fan to pull or push air across all the heatsinks...like a car radiator shroud...just smaller.

 

[laatsch55]

John, we've done the fan thing --here-http://forums.phxaudiotape.com/lee-s-white-oak-1000-t1802-20.html

Joe has got some other mods in the works, he suffers the same perfectionist tendencies with his engineering problem solving , a bad ass combination. thee is room for improvement and he's workin on it.

 

[laatsch55]

Let us not forget the original amp god--Bob Carver, then Dean the factyory Tech, Ed Blackwood-his neighbor and restorer extrordinaire!!
If i could ever get Joe and ED to talk Ed has come up with a fix that only Joe would understand and it's an earth shaker. Solves numerous problems at the electron level and allows further improvement, no shit, it's a biggie.
And for DC protect Big Don--love his boards.

 

[laatsch55]

Oh and John, Joe and i are working on a 1.3 to 1.4KW version of the board, dual mono, toroid PS and ------other stuff-----