Time to WOPL my 700B

[Pulpmillguy]

OK guys...need some help here. I've had my 700B for a few years and the left channel went out, tried some troubleshooting but had a little "incident" where all of the magic smoke came out so I've decided it's time to bite the bullet (and rob a bank) and go full WOPL upgrade on the old gal. I really miss the brute power and amazing sound and need to bring it back to life.

Now for the question before the house...do I do the work myself or can you recommend somebody on this side of the pond to do the work? I dread the paperwork sending it out/back in the EU and the shipping to the US will be a killer...so any leads over here would be appreciated.

If nobody is available, I feel that I'm up to the task...no stranger to a soldering iron and have followed many of the builds that have been documented here...looks like something that I could tackle with some help of the wonderful folks here in this group. Besides, I need something to do during these long winter nights.

 

[mlucitt]

You are in the right place for advice, so here goes. I recommend the WOA PL700 Capacitor kit. This makes your Power Supply more robust and reliable.
Once that is out of the way, you need the WOA PL14_20 Rev G1 Dual Mono Control Board wired for Full Complementary operation. This comes as a kit, and you can assemble it yourself or I can assemble and test the Control Board and send it to you with install instructions; then you can replace your Phase Linear control board easily enough.

That is the easy part. The Full WOPL includes the WOA Backplane Board Kits, (24) new Output Transistors and Sil-Pads, a new Bridge Rectifier, a WOA LED Light Board, (2) new Input Jacks, (4) new Speaker Binding Posts, (2) new Volume Level Potentiometers, and a some hardware including lots of small Tie-Wraps. The Backplane Boards are very difficult to assemble because of the small parts and the large wattage soldering tool required because the Backplane Boards contain so much copper. I can assemble and wire up these Backplane Boards for you and that only leaves one more challenge. The installation of the Backplane Boards is a serious commitment, and requires some experience and skills that some of us have developed over time. However, if you think you can disassemble your PL700B down to the bare chassis and rebuild it, then you are welcomed to try. There are videos on this forum to help you and lots of encouraging members who can supply helpful (and some critical) comments to make your Full WOPL a success. Oh, and a Watts Abundant DC Protection Relay/Delay Board is also a part of the upgrade to prevent loss of speakers and eliminates the turn on, and turn off "Thump" that some Phase Linear amplifiers exhibit.

Where are you located?

 

[Hexis22]

Welcome to the 700B upgrade club…

Sorry, I’m not familiar with anyone on your side of the pond with experience on White Oak upgrades.

As mentioned, the backplane boards will require at least an 80-120W soldering equipping to complete a robust job.

What soldering equipment do you have access to for this project. That may determine if you assemble yourself, or purchase fully assembled boards.

 

[laatsch55]

There are 3 or 4 White Oak authorized builders in the EU. Joe can line you out there.
I built a 700 Ser II for a guy in Poland and yes
...it was pretty steep.

 

[FredR]

I've gotten a lot of satisfaction from doing the build myself. But there are some awesome builders here. True craftsmen.

 

[Pulpmillguy]

You are in the right place for advice, so here goes. I recommend the WOA PL700 Capacitor kit. This makes your Power Supply more robust and reliable.
Once that is out of the way, you need the WOA PL14_20 Rev G1 Dual Mono Control Board wired for Full Complementary operation. This comes as a kit, and you can assemble it yourself or I can assemble and test the Control Board and send it to you with install instructions; then you can replace your Phase Linear control board easily enough.

That is the easy part. The Full WOPL includes the WOA Backplane Board Kits, (24) new Output Transistors and Sil-Pads, a new Bridge Rectifier, a WOA LED Light Board, (2) new Input Jacks, (4) new Speaker Binding Posts, (2) new Volume Level Potentiometers, and a some hardware including lots of small Tie-Wraps. The Backplane Boards are very difficult to assemble because of the small parts and the large wattage soldering tool required because the Backplane Boards contain so much copper. I can assemble and wire up these Backplane Boards for you and that only leaves one more challenge. The installation of the Backplane Boards is a serious commitment, and requires some experience and skills that some of us have developed over time. However, if you think you can disassemble your PL700B down to the bare chassis and rebuild it, then you are welcomed to try. There are videos on this forum to help you and lots of encouraging members who can supply helpful (and some critical) comments to make your Full WOPL a success. Oh, and a Watts Abundant DC Protection Relay/Delay Board is also a part of the upgrade to prevent loss of speakers and eliminates the turn on, and turn off "Thump" that some Phase Linear amplifiers exhibit.

Where are you located?

Where to start...I am located in southern Finland, hence the reluctance to send the amp across the pond. I have tinkered with electronics since in high school, built some SWTPC kit amps that really rocked but my PL sounded SOOOOO good, I need to get it back. I have an assortment of equipment (15, 100 and 48W adjustable irons, multimeters (unfortunately Fluke is a little above my pay grade ), signal generator/scope) so I think I am prepared for the undertaking.

I already have the WA DC protection relay board and all of the goodies you recommend for the full blown treatment sound like just the ticket. I am looking for some good instructions for the complete rebuild, you mention that there are some good videos on the forum...could you point me in the right direction as I haven't found them yet.

I have been looking at some of the WOPL upgrades Eric has done (that man does FINE work) and given the proper instructions and encouragement from the group I think I can do it. Stopped by WO website and it looks like I will be into them for about $700 of parts...and that is using my chassis, faceplate and meters. What about this triac power switch that Eric has used in a few of his builds...where can I snag one of those guys?

On one of the builds, there was a comment about reworking the holes where the output transistors mount, what is the deal there?

I have also been wondering what is with the transformer mods...why the isolation of the core from the assembly hardware? Is it a noise issue or an electrical one?

As you might have noticed, I have a lot of questions but I guess that is what keeps us out of trouble...or maybe IN trouble.

Looking forward to this undertaking and working with this fine group!

 

[Hexis22]

I would highly recommend you include the WO chassis with your order. This provides an IEC power inlet socket, machined screws for attaching covers, and most importantly increased seperation of internal components (control PCB away from AC and other noisy circuits/wiring).

The Triac power switch is from Don at WA, the same place you found the DC protection board. It's not on his website, just email him and request a Triac power switch.

Mounting the TO-3 outputs using the WO backplane boards requires increased heat sink hole placement accuracy than typical stock configuration. Making a small hole diameter increase allows mounting the heat sinks up to the housing using nylon stepped washers provided by WO. The stock heat sinks holes may not always lineup with the chassis holes without this small update.

Isolating the transformer mounting bolts will help provide additional noise reduction due to eddy currents induced into the bolts and potentially chassis ground.

 

[mr_rye89]

Joe sends instructions, also Mark W Comer has videos on YouTube. Use good quality lead/tin solder and you’ll need a hot iron for the PEM nuts on that backplane. I think I used my Weller 100/140 on my PL400 4 fin build

 

[Hexis22]

After you place your order with White Oak, Joe will send you an email with all the detailed assembly documentation.

This email will contain more information and detail than you can imagine.

Read all files completely, multiple times, before starting your project.

Just about ALL questions I had during my first build was answered in Joe's detailed documentation. It's a big project that requires lots of patience, extensive soldering skills, good hands on mechanical assembly skills, and electrical knowledge to successfully complete.

Break down the project into small sections, eat the elephant one bite at a time, and RE-READ each step before proceeding to the next section.

Patience and RTFM will get you most of the way there with these quality WO kits.

The sense of accomplishment after completing this type of project is phenomenal... not to mention the detailed, powerful, and accurate sound.

 

[Vintage 700b]

Where to start...I am located in southern Finland, hence the reluctance to send the amp across the pond. I have tinkered with electronics since in high school, built some SWTPC kit amps that really rocked but my PL sounded SOOOOO good, I need to get it back. I have an assortment of equipment (15, 100 and 48W adjustable irons, multimeters (unfortunately Fluke is a little above my pay grade ), signal generator/scope) so I think I am prepared for the undertaking.

I already have the WA DC protection relay board and all of the goodies you recommend for the full blown treatment sound like just the ticket. I am looking for some good instructions for the complete rebuild, you mention that there are some good videos on the forum...could you point me in the right direction as I haven't found them yet.

I have been looking at some of the WOPL upgrades Eric has done (that man does FINE work) and given the proper instructions and encouragement from the group I think I can do it. Stopped by WO website and it looks like I will be into them for about $700 of parts...and that is using my chassis, faceplate and meters. What about this triac power switch that Eric has used in a few of his builds...where can I snag one of those guys?

On one of the builds, there was a comment about reworking the holes where the output transistors mount, what is the deal there?

I have also been wondering what is with the transformer mods...why the isolation of the core from the assembly hardware? Is it a noise issue or an electrical one?

As you might have noticed, I have a lot of questions but I guess that is what keeps us out of trouble...or maybe IN trouble.

Looking forward to this undertaking and working with this fine group!

Hello Pulpmillguy,
I will just throw in my 2 cents worth here. I have built (3) completely WOPl'd 700b's and the quality of the White Oak Components, incredibly thorough instructions, and all the support that you can ever ask for here on the forum, are all great reasons to do this yourself. I can't emphasize enough how enjoyable doing the build yourself is. I also have had a 700b in my life since the late 1970's and absolutely loved it. The final fully WOPL'd 700b that you build, will blow the stock unit out of the water. I listen to one of mine every day, I kept two, and gave one to my nephew as a graduation present when he got his Masters degree a few years ago. I also recommend the triac switch, from Don at Watts Abundant. All 3 of mine have that Triac switch in them. It's the details that make the difference. Every time you listen to your WOPL'd 700b, you will also know that you built it yourself. Eric has added some very great ideas for your build as well. His work is impeccable.

 

[Pulpmillguy]

OK, no turning back now...WOPL here I come!


I've basically got my shopping list together and it looks like this:



After looking at that rebuild that Eric did using that badass black faceplate that's the route I'm going to go. I'm also taking your advice and going to the upgraded chassis for a little more "wiggle room".

I can't wait to order the parts but unfortunately will be out of the country for 3 weeks and I don't want the stuff to get to customs while I'm gone so I will have to wait...

 

[Vintage 700b]

OK, no turning back now...WOPL here I come!
View attachment 77220

I've basically got my shopping list together and it looks like this:

View attachment 77221

After looking at that rebuild that Eric did using that badass black faceplate that's the route I'm going to go. I'm also taking your advice and going to the upgraded chassis for a little more "wiggle room".

I can't wait to order the parts but unfortunately will be out of the country for 3 weeks and I don't want the stuff to get to customs while I'm gone so I will have to wait...

Looks great, just remember ..............this stuff is addictive..............you can't build just one !
You definitely won't regret doing it yourself, and it will be worth the wait.

 

[Hexis22]

Please see my PM regarding your parts list, you will need additional components.

For example, you will need both PNP and NPN outputs for full comp configuration...

 

[WOPL Sniffer]

I hope your soldering is up to speed.... ROUGH crowd here so take your time and do it right.

 

[mlucitt]

You will have the best amplifier in Finland. Do you use a 240V to 120V voltage converter for the Phase Linear amplifier?

 

[Pulpmillguy]

I hope your soldering is up to speed.... ROUGH crowd here so take your time and do it right.

Oh I hope I can live up to the high standards of the group. I will be posting lots of pictures from the build and I expect you guys not to hold back on your comments...that's what keeps us on our toes.

 

[Pulpmillguy]

You will have the best amplifier in Finland. Do you use a 240V to 120V voltage converter for the Phase Linear amplifier?

That would be one big ol' stepdown transformer...but I do have a smaller 500w unit that I use for my jukebox and some other small goodies that I brought from the States with me.

The amp came via Italy so it was already wired up for 240.

 

[mlucitt]

The amp came via Italy so it was already wired up for 240.

Your transformer looked like it did not have enough wires for 120V/240V operation. Also, I thought most PL700B amps were not dual primary...
But, congratulations, using a stepdown is a pain.

 

[WOPL Sniffer]

Yeah, I'd be careful, 700B doesn't have the dual primary to use on 220-240..... Not that I'VE seen anyway. Don't trust some yo-yo's wiring.

 

[George S.]

It's in the photo on post #11. I was going to say to carefully tag the wiring before disassembly. Too late now. Carefully identify the leads and bench test it before starting your build.
Gene had issues identifying his weird 400 S1 export transformer wiring as the primaries were all black if I remember correctly.
Going to take some resistance testing and scratch paper to figure out what's what and bench test it for proper input and output. Be careful not to short it out.
Should keep you occupied until the kits(awesome they are!) arrive.