PL 700B WhiteOak-which mods to do?

[Hexis22]

Let the fun begin!

I'll start a build thread after parts arrive.

 

[FredR]

Been around for years. This community ROCKS!

 

[NavLinear]

You made the right decision. You'll have a amp you can pass on to the next generation. Congratulations!

Lady Kravchenko or Eric? Hmmm

 

[josephancion]

Hi am a newbee to this site but an old school dog of a Tech. where can I find a PL700B Meter(s) or Equiv.
Thanks!! Base on this post of recommendations, my WOPL boards (2) are on the Way to me.

 

[WOPL Sniffer]

Dang, Talk about hard to find........ You shoulda built a Series II..... Meters are easy to be had. Usually nobody will give up 700B Meters. JOE???????

 

[mlucitt]

where can I find a PL700B Meter(s) or Equiv.

There were several makers of the PL700B meters. It seems to me that Jewell was the most common, followed by Honeywell and Dixson.
I spoke with an engineer at Jewell Instruments in Manchester, NH about a year ago and although he was sympathetic to our dilemma, he said that Jewell had no "upside down" meters or parts even though this style of meter was very common in the 1950's through the 1970's in switchboards and industrial applications.
He said they had thrown out (!) all those meter parts (movements, dials, and cases) about 15 years ago because there was no longer any calls for them. He also said to retool and create 100 of those meters would cost about $100,000.00 or about $1,000.00 per meter. Of course, if I wanted 1,000,000 of them the cost per unit would go down...

Unfortunately, the PL700B meters are fragile and they do wear out because they are at least 40-50 years old. Some folks on the forum have been successful making one good meter out of two bad ones. I have two new PL700B clear meter lenses, but no meters. The PL400 meters, which are not upside down, are much more common.

Also on the list of rare PL original parts:
Black Meter Bezels
Transformers and the Aluminum Cradles
Sub-chassis Plates (for the Series II amps)
Rack Handles
"Phase Linear 700B" Logo Faceplate Plastic Plates
Aluminum Faceplate Bolts (for the PL400)
Round Aluminum Knobs (especially the solid ones)
Transistor Covers
Did I forget anything?

Good luck in your search.

 

[WOPL Sniffer]

The faceplate inserts for the 700B are available (even IF they are aftemarket). The "WOPL 1000" insert is harder to get.....

I'm down to a couple packs left. One of our newest builders has been gobbling them up

 

[josephancion]

Good news for me! as Circumstances would have it, I found a beat up PL700B with Two good meters for 300 buck. well worth it. IT unfortunately was dropped and the frame is demolished. definitely for parts only. WOPL finally answered me back. so, Control board is next. Happy Dance!!!

 

[Vintage 700b]

Good new for me! as Circumstances would have it, I found a beat up PL700B with Two good meters for 300 buck. well worth it. IT unfortunately was dropped and the frame is demolished. definitely for parts only. WOPL finally answered me back. so, Control board is next. Happy Dance!!!

Joe's (White Oak) chassis is a huge update, to that original, take a look at some of the latest 700 builds that are posted recently.

 

[WOPL Sniffer]

Good news for me! as Circumstances would have it, I found a beat up PL700B with Two good meters for 300 buck. well worth it. IT unfortunately was dropped and the frame is demolished. definitely for parts only. WOPL finally answered me back. so, Control board is next. Happy Dance!!!

WOPL finally answered you back????


HUH????

Do you mean Joe from White Oak Audio Design???? Noobs.........

 

[mlucitt]

Noobs.........

We were all noobs at one time, even you Sniff.

 

[WOPL Sniffer]

We were all noobs at one time, even you Sniff.

Yeah but I never called the man WOPL.

 

[J!m]

That’s Mr. WOPL private!

 

[josephancion]

Yes Sir! Admiral WOPL it is. I can wait for the new Control board to be finished. Just fix the original PL700B PL20 board. It had some osc traces in the audio, I heard the audio distortion, but needed to look closer. (Used a Scope to verify my ears), interestingly thought only the Upper part of the Sine wave had ringing. one channels audio affected the other with this ringing. I added a 200pf to both drivers phases (B, C) and removed the 130 Ohm with the .05 uf Cap. since I replaced the TO-3 outputs with sorted MJ21194's. The sine wave was distorted on high freqs. (8000 hz.). Left channel was originally blown to bits when I got it, (shameful, people would install 15Amp fuses!!) the Bias Pot was cooked in the original blow out when I got it. Bias had no adjustment results. Audio now is much better, clean.

 

[laatsch55]

Amazing how many problems these amps can have over time...

 

[J!m]

That’s why sniff suggests replacing all but the transformer.

 

[josephancion]

Joe from WOPL, Wherever you are, Admiral sir, I purchased Three WOPL Control boards and installed two today. one on a PL700B and the other on a PL400. Nice work on the PCB's. performance is improved and they look fantastic. not to mention the sound is great too.!!!!! HAPPY DANCE, Saturday Night Fever here I come baby!!