Twin Reverb Filter cap board

[Guitarzan]

Hi guys.
I'm a new member here so if I make any newbie mistakes, please correct me. I'm not thin skinned so fire away if I do anything wrong.

OK. Here's my issue:
I got this '76 Twin Reverb Chassis that was pretty well trashed off of the web and have decided to "blackface it". So I bought the small parts kit from Mojotone and right off I noticed that there was a discrepancy in the documentation. If you look at the Instruction Manual they have posted online, page 3 shows a picture of how to orient and wire the filter cap board. It's photo 6 Filter Cap Board Assembly and it can be viewed here:

http://mojotone.com/manuals/BF Twin Reverb.pdf?ck=a9_e8Ue-AdjQYCoN&vid=a9_e8Ta-AT-KsO6V&cktime=114296&cart=177544&gc=clear

The kit, which is very nicely organized and comes with the schemo and layout diagrams, has a on a separate page the layout for the filter cap board.
You can see it right here:

http://mojotone.com/Amp Kit Schematics and Wiring Diagrams/Blackface Kits/BF-Twin-and-Super-Reverb-Filter-Cap-Board.pdf?ck=a9_e8Ue-AdjQYCoN&vid=a9_e8Ta-AT-KsO6V&cktime=114296&cart=177544&gc=clear



My question is, do the two versions of the filter cap board conflict with each other? The cap board I took out of the amp is wired like the photo on page 3 of the manual. It looks like you'll have to copy and paste the links into your browser to see what I'm seeing and what has me confused.
It's always please and thanks guys.
-dale {8^)

[HotBluePlates]

My question is, do the two versions of the filter cap board conflict with each other?

Take your second filter cap board layout, and spin the entire thing 180 degrees. Then you'll see they are the same.

Other than that, there is one difference: the plus/minus orientation of the 100uF is opposite. As long as you connect the - of the total series string to ground and the opposite, +, end to the rectifier output, you'll be fine.

Another way to say this is follow one diagram or the other in its entirety, and everything will work.

A sidenote for the curious: the photo of the filter board shows white and green wires. On the original fiberboard, these were bare wires on the underside of the board (not the upper side with the caps). But that was okay because there was an additional insulating fiberboard between the filter board and the chassis. I assume Mojo shows it the way they do because it leaves less chance for error on the part of the builder (every connection is where they can see it at all times).

[SILVERGUN]

Welcome aboard....
It helped me to flip the one picture over to confirm that, yes, they are similar setups, but the difference is where the "A" nodes come off of the 100uf caps

It would be OK either way, because it serves the same end result

I was typing while HBP was posting,,,so I'll put this up just as confirmation

[sluckey]

They are slightly different but either will work if you pay close attention to the polarity of the two series caps.

[Guitarzan]

Oh! Wow! Hey thanks guys 
I was getting email notices of replies to my newbie posts but I guess you have to tell the system to notifiy you of replies in each forum. I didn't think I was getting any takers on this issue.
Yeah, my confusion was with the "A" node in the diagram.
Thanks to all who took the time to help out with that one. It suddenly becomes quite clear when you actually do "Pay close attention to the 2 series caps" Thanks slucky!
BTW, the cap board I took out had enormous paper caps with bare wires making all of the connections on top of the board. Not between the two boards as one member stated. Could be it was left to the preference of whoever was assembling cap boards that day? The wires and resistors are basically buried under the massive caps which are all touching side by side and the only ones that were insulated are the ones that actually exited the cap housing and went into the main chassis through those plastic grommets. The grommets that come with the small parts kit are rubber. I don't know if I like those better or not. They seem like they might hold up longer, but are a lot harder to pull the wire through. Especially if it starts to get tight with several wires.
Thanks again to all
-d {8^)

[sluckey]

I guess you have to tell the system to notifiy you of replies in each forum. I didn't think I was getting any takers on this issue.

The notification is topic specific. IOW, you must tell the system to notify you of replies to any particular topic, such as this one.

[Guitarzan]

Thanks sluckey!
I'll have to remeber that when I run into more issues which I'm sure to do. I've never tackled a build quite this big or complicated but I have done a mess of champs and a handful of tweed deluxe builds and all came off without a hitch. I'm really good at following directions and attention to detail. I reworked a SFVC that I copped from a guy who I corresponded with for a good couple of years. Maybe more. He was a great well of Fender information and I valued his friendship very much. Then one day he sort of just fell off of the map. It's too bad really. Anyway, I've tinkered with a few Bogen P.A. amps too. Mostly stuff that was already working so I've never had to dig into one and really shoot trouble like a lot of you guys who have all of the actual skills and know-how. I consider pretty much everything I've ever done a "paint by numbers" affair, or a simple matter of matching and swapping out filter caps and such. That's why I stress the hope that you guys with the real skills will put up with me as I'm bound to ask some pretty stupid questions and probably soon than later.
So what I have here is a SFTR from about '76 that was a mess. It was just the chassis and was already canibalized for the choke, and the rectifier board so on the suggestion of that guy who fell off the globe on me, I decided to blackface it. I got the small parts kit form mojotone and a faceplate from TAD. It looks authentic but I'm thinking it almost has to be a repro, doesn't it? I got a pair of 12" JBLs off of eBay for less than I've seen many single 12s sell for and cabinet that looked rough at first, but cleanup up very nicely. So all that's left now is the hard part and I couldn't even get past the filter cap board w/o sending out an SOS so I really appreciate having this forum to bounce my qustions around in. When I finally fire it up I'll be in the market for a new handle, grill logo, and a set of legs, all age appropriate to finish off the cosmetics. I have no intention of trying to pass it off as authentic but as long as I've decided not to go with new tolex and grill cloth, I might as well put used harware on it and let the ultimate new owner decide what he wants to tell his friends. It's going into a local auction for a musician friend of mine who needs surgery and can't afford it. We've has a number of fund raisers so far, but still have a long way to go so I hope this donation will bring a couple of G-notes to the fund. OK... I'm writing a book here so I'll quit now.
Thanks again to all.
-dale  {8^)

[Guitarzan]

Well guys, I have started the twin reverb for real. I wired the filter cap board and the rectifier board. I did (of course) leave the nodes that connect the boards to rest of the circuit unsoldered. Today my plan is strip the rest of the old components, wiring, and misc hardware out of the chassis and clean it within an inch of its life. I'm also determined to figure out how to post pictures in here like you guys did with the picture from the manual and the layout drawing. I want to make sure and get before and after shots posted as well as in-progress pix. For those who are interested.
Thanks again to all who posted replies. I truly appreciate the help. I only wish I could return the favor in kind. The old filter cap board is up for grabs. If anyone wants it, you can have it for the cost of the postage. It's actually pretty clean and is loaded with vintage Mallory caps. They're the old paper ones and enormous compared to the modern ones. There's no sign of any visible damage, leakage, burning, or anything. I'm guessing they could be reformed and reused in a project where you want only vintage components.
TTYL
-dale {8^)
Here's a picture of that cap board. I guess the best way to go is for you to send me a self-addressed flat-rate priority mail box. The smallest and least expensive they have should work. Or whatever you think is the best way to do it. Anyway, the priority mail thing was just an idea. Just let me know if you want it and how to proceed.

[Guitarzan]

I think my problem with posting a jpg was that I didn't read the part about it not showing up in the preview. So here goes nothin' I'm going to see if I can post the "before" picture.