Bulk Capacitor Replacement Procedure for the PL 700B

[laatsch55]

I second Dennis. Well it all makes sense now. I checked my PayPal statement, and two months ago I bought that PL 400 from "jblackwood". Hello? Ding ding! (duh to myself) Well in a photo I provided in this post, I show a stack of PL gear, and there's a 400 in there. That one came from ED. I have the very list of the things he did to it. The ONLY thing I did myself was put a WOA light board in there. I have the original still, with new lights. That amp, I will be selling soon, and offering to the Phoenix guys first. My desire is to simply have two 700B's in bi-amp configuration. (one WOA'd out). I have no need for a third 700B (also on upcoming auction block; and that 400). Ed did a fine fine job to the internal components! Even new transistors. New caps on the original driver board and new bulk caps etc. Flawless in my opinion. Just waiting to finish upgrading some PL's with WOA gear, before I start parting way's with amps. To make sure I have working stuff. That's a fine crossover you got there Lee. You're way more serious than I. Sadly.....my money is tied up in WOA at the moment.


View attachment 9097

I also have a Pioneer D-23, the 850 belongs to my son.

 

[fitz43]

I have a Pioneer SF-850 in the Buy/Sell/trade forum......

Is a Nakamichi E-204 any good?

 

[laatsch55]

Not familiar with that one Doug.

 

[fitz43]

Not familiar with that one Doug.

On the local CL. Always been curious about bi-amping. Lord knows I have too many amps.....

 

[NavLinear]

On the local CL. Always been curious about bi-amping. Lord knows I have too many amps.....

I've heard that tri-amping is more fun! Uh- oh

 

[Phase Linear Phanatic]

I've heard that tri-amping is more fun! Uh- oh

Why did I feel that one was just left open for Dennis? Was it just me fella's? Anybody.....anybody?........

 

[fitz43]

I've heard that tri-amping is more fun! Uh- oh

Depends which part of the sandwich you end up being....

 

[laatsch55]

Why did I feel that one was just left open for Dennis? Was it just me fella's? Anybody.....anybody?........

Yes Dave, that was classic Nav bait.

 

[NavLinear]

Tri-amping is sorta like five play.

That's one better than four.

 

[Phase Linear Phanatic]

I see what you guys meant when I introduced myself a few weeks ago. "To be on the lookout for self hijacking your own threads?" It's all good though. Ha hah! Ahem...allow me to get back on topic......

I got the Bulk capacitors replaced and working. Calibrated my meters thanks to Joe, and have received his driver board Rev "D" populated with the germanium transistors. I have gold plated RCA Jacks ready to be installed along with that board AND, possible some shielded cable. I don't know which thread I saw this in; but someone mentioned helping to reduce the noise floor by using some grey shielded analog two wire cable for the meter gain pots in the PL 700B. I happen to have access to bulk rolls of the stuff, along with unending rolls of heat shrink and cable ties. My job as an electrical industrial control panel wire tech, allows me to bring the scraps home. If this is a good idea, I may add this too while I have the amp open for operation. Joes board, the jacks, and the wire all go in this weekend. Then its mandatory ten hours a day, 6 days a week for work. Mandatory Saturdays starting next week. So I better get this thing done in two days.

Here is a picture of what I wired this week. Usually on a weekly basis. So wiring this amp doesn't scare me at all. LOL!

 

[orange]

I leave the hard installation work to Nav and his avatars.

 

[laatsch55]

I see what you guys meant when I introduced myself a few weeks ago. "To be on the lookout for self hijacking your own threads?" It's all good though. Ha hah! Ahem...allow me to get back on topic......

I got the Bulk capacitors replaced and working. Calibrated my meters thanks to Joe, and have received his driver board Rev "D" populated with the germanium transistors. I have gold plated RCA Jacks ready to be installed along with that board AND, possible some shielded cable. I don't know which thread I saw this in; but someone mentioned helping to reduce the noise floor by using some grey shielded analog two wire cable for the meter gain pots in the PL 700B. I happen to have access to bulk rolls of the stuff, along with unending rolls of heat shrink and cable ties. My job as an electrical industrial control panel wire tech, allows me to bring the scraps home. If this is a good idea, I may add this too while I have the amp open for operation. Joes board, the jacks, and the wire all go in this weekend. Then its mandatory ten hours a day, 6 days a week for work. Mandatory Saturdays starting next week. So I better get this thing done in two days.

Here is a picture of what I wired this week. Usually on a weekly basis. So wiring this amp doesn't scare me at all. LOL!

View attachment 9184

Good, any CM, CMR, CMG type shielded in a 20 or 22 gauge is fine. From the inputs to the pots, from the pots to the board. Isn't Joe's board a thing of beauty??

 

[laatsch55]

Those are tough panels to wire and be consistent in appearance. I wre all our pump panels and water plants for our oil company.

 

[Phase Linear Phanatic]

Those are tough panels to wire and be consistent in appearance. I wre all our pump panels and water plants for our oil company.

They are indeed. Campbells, Purina, Unilever, PepsiCo, to name a few.....just huge panels the size of two full sized double garage doors. And to have to make them appear and be perfect to boot? From what I am told, once they arrive in the field, the field techs tear em apart anyway, and all that nicey stuff is wasted. But; owell. I'm not paid enough to worry about that. At least I CAN apply that neatness here. In my PL projects. Joe's boards are a great example as you have seen from a couple of my photo's. (More soon to come.) I recieved the rev D board today, as well as my bridge rectifier parts and new RCA jacks. Also got shielded analog cable, wire ties and heat shrink from work. I have a very busy weekend ahead of me. Will follow up. And yes. I brought home both 20 and 22 guage wire shielded from work. Gonna try the 20. I stare in awe at Joe's board. Agreed. It IS a thing if beauty! Even with my O.C.D perfectionism, I still could not match the amazing solder work. I'd swear it was done by a wave solder machine?! And to churn it out so fast? Way to go Joe. You outdid yourself again on this one!

 

[laatsch55]

I sent Ed Blackwood a baord to use in his personal 700B, he also wondered who did my wave soldering.....

 

[Phase Linear Phanatic]

I sent Ed Blackwood a baord to use in his personal 700B, he also wondered who did my wave soldering.....

I think Joe has a machine in his shop that does it. He just doesn't want to tell anybody so he can bask in the glory of the "Joe/Soldered by hand" board work! LOL!!

Finally my mammoth task of messing with the three B's, is complete. I have only one unsolved mystery left. The WOA'd PL 700B, has considerable hum that wasn't there before. It's anyone's guess as to why; as I replaced everything in there except the transistors on the back pan? I DID snip the solid wire going to the RCA bar, and going to the speaker binding posts, so the only wire left was the ground running from the normal switch to one of the bars against the back wall, which eventually lead to the bulk cap center buss bar. I used shielded cable all throughout the pots, sooooooooooo aside from sending it to a more experienced individual; this is all THIS "do-it-yourselfer" is gonna do? I have another 60hr work week ahead of me, so if anything happens at all, it won't be till next Sunday. I will update the picture album sometime in the morning. For now.....BED.

 

[laatsch55]

There is a cure to the hum, you're not getting off that easily. Post about your picture posting problems and Jer can help ya. We're gonna need a lot of pics to solve the Hum problem. Forv I too have had my share of HUMMMMMMMMMM.....

 

[laatsch55]

The negative speaker posts need a separate wire going to the star ground also.

 

[Phase Linear Phanatic]

The negative speaker posts need a separate wire going to the star ground also.

Not getting off that easily huh? Well okaaaaay? You asked for it. Prepare to be pestered with MORE unending questions! LOL! As far as running a new ground wire across the negative speaker binding posts, and over to the star ground (bulk cap buss bar), I thought that was why they originally had that solid wire in there? it ran to the normal/direct coupled switch then along the back wall, over TO the star ground? Wasn't that just as effective? If I don't get the logic of simple "ground scheme structure".....please, school me. All and any guidance to enhance my understanding of these amp has been and IS appreciated! I've learned way more about the workings of this thing than I EVER did in the past few weeks. And to think.........I spent 30 years thinking it was a box with Pretty lights and moving needles! He he!.............

Well.....off to work a ten hour day. See you near midnight. I will try to pick up some 18 gauge black at work for the ground.

 

[Gepetto]

If you follow the grounding schematic literally and explicitly then You should not face hum issues.
The normal/direct switch body should have NO wire connecting it to the floating copper input plate. The switch body will become chassis ground by virtue of the screws that mount it. All those little bus wire jumpers that PL added should be removed. The only bus wire jumper should be between the 2 negative speaker binding posts (this is shown on the schematic)
The end result should be that the ONLY connection between the star point ground and chassis ground occurs at the center lug of each of the 3 terminal solder lug strips mounted to the backplane

Hope this is clear