What holds the eyelet board in a 5e3?

[mbratch]

Sorry - noob question:

I am just getting started on my first 5e3 kit. I'm used to poking around inside BF amps that have the eyelet board fastened to the chassis with a couple of sheet metal screws. But this board doesn't have any mounting holes, nor does the chassis. I noticed looking at pics of the insides of various 5e3's that there aren't mounting screws (that I could see anyway).

So, I can see how the wiring might hold the eyelet board in perhaps, but what about the insulating board underneath? What holds that in place if that's how it works?

Thanks!

[Resonator Guy]

Here is one I can answer since I asked the same question a while ago. Follow this thread. There are some good explanations and pictures. I used two sheet metal screws with PVC spacers from cleaning bigger wires between the boards and it seems to have worked perfectly. There are pics of where to drill your holes and all.

http://music-electronics-forum.com//...ad.php?t=11796

[Mandopicker]

If you really want to locate the screws in a similar location as Fender, you might try and find images of a vintage 5E3 for the relative screw position. In truth being exact doesn't really matter other than for vintage asthetics.

Either way...

If using sheet metal or self tapping screw type, mark the chassis and drill pilot holes smaller than the screws themselves. You do not have to use that type of screw as a screw/nut combination would do just as well.

Hint...position the board inside the chassis so that the screws can be reached with the board fully populated. This will make future repairs and removal easier withour removing parts. Mark the holes to match the predrilld chassis and drill through both the board and the backing board.

* I would find these locations before you solder everything to the board (Dry fit to be sure.) Not necessary but perhaps good form.

No need for stand-offs.

Hope this helps.

[mbratch]

Thanks guys.

For some reason, when I first looked at pics of vintage 5E3's I didn't see the mounting screws. Looking back, I do see them now. I think I need new glasses.

So that all makes perfect sense.

I think stand-offs are necessary for the "hard", single turret board designs I've seen occasionally.

I'm excited about getting started on this...

[tubeswell]

FWIW I use spacer nuts between the board and the chassis

[Mandopicker]

Here are just a few obveservations I have made after making several amps or varying design.

IMO stand-offs seem to be better utilized when the main board is used without a backing board. Not to say that it cannot be used with a double layer design, but the whole purpose of the second layer is to insulate the connections from the chassis, and to perhaps even keep wires sandwiched in their place and vibrations to a minimum. (I have seen higher gain amps with only two spacer towers used, so to speak, that allowed the board to vibrate causing rattling or other related noises.) If using spacers, I would suggest supporting the board at 4 corners to alleviate that vibration potential. I have used thin phenolic material with 10mm spacers and no backing board knowing that the wires were significantly insulated from any possible chassis connection, and vibrations were minimized.

Either way is good if it is what you choose to do. Just consider that in a traditional 5E3 chassis design, the higher you raise the board off the chassis, the closer you bring some connections to input jacks and other areas that could cause oscillations. Just think the design through carefully so you don't have to take it all out again and start over.

I also suspect that Leo chose a thin two layer design attached by self tapping screws for simplicity, and cost saving measures. By not having to purchase large quantities of spacers, washers, and nuts, Fender probably saved thousands. The board material probably cost very little in relation.

Not trying to preach, but perhaps these thoughts are useful.

[Ben]

Hi all,

First post. First time builder. Mojo 5E3 kits just arrived last friday and i too was wondering how the eyelet board attached. Some of my questions were answered in this thread and the one linked, but i was wondering about a couple things.

1. whats the proper spacing between the eyelet board and the insulating board? are they flat up against each other or is there a standard spacing?
2. how far should the insulating board be from the chassis? or maybe it should be flush up against the chassis? I mean how much space should be between the planes made by the insulating board and chassis, not how far should it be from the right end of the chassis.
3. my parts list has a line that reads "tweed chassis screws". are these the screws I'm supposed to use? or does anyone know if the mojo kits come with hardware for mounting the eyelet board and if so ..which peice is it?


thanks for the help!

[Resonator Guy]

5E3 eyelet board

Ben, I just used a little guesswork and logic on the spacing.
I used a couple of pieces of insulation from the PT wires between the two boards with the two screws through the insulation and the holes I drilled.
I figured you just need enough space so as not to crush the wires between the boards.
I put the bottom board flush on the chassis, because it pretty much had to be that short to clear all the other equipment, especially the input jacks.
I didn't get any screws but used appropriate length sheet metal screws and they seem to be working well.
The amp works and sounds terrific. I took it out for the first time to a Blues jam last Friday night. I did take a backup but didn't need to as it performed admirably.
Hope that answers your questions. Good luck.

[tubeswell]

Hi Ben welcome to the forum

Hi all,
1. whats the proper spacing between the eyelet board and the insulating board? are they flat up against each other or is there a standard spacing?

No 'proper' spacing. The insulating board doesn't perform any EMF blocking function, so you can put it however close/far away you want from the main board. Most peeps sammy it right behind the main board (allowing a bit of space for a few wires). I never bother with them personally - I just use spacer nuts from the main board to the chassis and use insulated wire for back of the board stuff.

2. how far should the insulating board be from the chassis? or maybe it should be flush up against the chassis? I mean how much space should be between the planes made by the insulating board and chassis, not how far should it be from the right end of the chassis.

Same sort of answer as for 1. (above)

3. my parts list has a line that reads "tweed chassis screws". are these the screws I'm supposed to use? or does anyone know if the mojo kits come with hardware for mounting the eyelet board and if so ..which peice is it?

If there aren't any mounting bolts in the kit, go down to your local electronics store and get some small bolts and nuts with some assorted spacer nuts. Probably quicker in the long run than waiting for them to arrive in the mail. Get the tranny mounting bolts and the chassis mounting bolts while you're there

[Ben]

Thanks guys,

There are alot of nuts and bolts that came with this kit, thats the problem..none of em really say what they are for. Reso Guy, was your kit a mojo and did it come with any hardware at all, or just no moutning hardware for the board?

I'm trying to figure out if i already have the hardware. I guess i could wait till the cabinet arrives and do a dry run and see whats left over hardware wise, but i wanted to get started.
All the other holes for this kit are pre-drilled. It would seem to me that everyne would want to put the board in the same place, as per vintage spec, I wonder why then these holes arent pre drilled for me just like the others?

Oh well, thanks again for the help, I understand about the spacing and will figure out the hardware or just use my own hardware to mount it. Unless.. anyone has built a mojo kit and remembers the screw size , or even if the kit came with that hardware?
Cheers!
-Ben

[Resonator Guy]

Hey Ben, mine is a mojo kit and it came with all the hardware except the sheet metal screws for the board. The mounting holes in the cab for the chassis weren't drilled either. You will need another person to help you line that up for drilling if yours isn't done.
BNWitt told me to use panhead #8 self tapping metal screws. Check this thread. There are some good pictures and explanations there.

Mounting Mojo 5E3 Tag Board

[Ben]

Thanks again for all the help.

My plan is to use the self tapping #8 panhead screws, two of them, with no spacers at all betwen the boards, nor between the chassis and the boards.
My thinking is that the wires will provide the necessary spacing betwen the two boards, and that the insulated board can be flush against the chassis with no space. I think this is how Fender did it?

If anyone thinks this is a bad idea, or has any additional suggestions or comments, that would be most helpful. I plan on drilling tomorrow and am gonna try a dry run of mounting everything i can first to make sure I have good fit and spacing....before i begin populating the board.

Thanks again all the help, what anexcellent forum!
Cheers
-Ben

[mbratch]

My plan is to use the self tapping #8 panhead screws, two of them, with no spacers at all betwen the boards, nor between the chassis and the boards.

My thinking is that the wires will provide the necessary spacing betwen the two boards, and that the insulated board can be flush against the chassis with no space. I think this is how Fender did it?

I also have the Mojo kit. Like the vintage Fenders, there should be a blank board that has the same dimensions as the eyelet board included in the kit. That board goes between the eyelet board and the chassis to insulate it. You do not want to mount the eyelet board without it. You need the insulator board, or PCB spacers. But a standard eyelet board uses the insulator board, as is done in the vintage Fenders.

As far as screws, you can use really whatever you like. Originally, I used two spare screws and nuts that came with the kit (the kit supplies plenty). But the spare screws were a little long so I went and bought some shorter ones. You can also use self-tapping, which is what the original amps used. I wanted to do that, but had trouble finding self-tapping. They seem to have gone the way of the Do-Do Bird in favor of self-drilling.

For placement, I looked at a few pics of vintage Fenders and located them in the same place as those. But any two reasonably spaced locations will work as long as you don't drill through a wire.

[Ben]

Thanks mbratch!

The hardware in the mojo kit was a mystery to me. I have 8 6-32 nuts and bolts that dont seem to fit anywhere. I was hoping they were for the tube sockets but they dont fit. i have nothing to mount the tube sockets with now, so i gues I wll be going ot the hardware store AGAIN. annoying. Dear Mojo, I paid $700 , please proved the 50 cents worth of nuts and bolts necessary to asemble this thing!

As for mounting the boards, there were NO screws of any sort appropriate for this. I went to the hardware store and bought self drilling ...assuming that they were the same as self tapping. Drilled a small pilot hole and behold...they actually did tap a nice threaded hole in my chassis. they work perfectly.

Unfortunately, I ran out of cloth covered wire..and now have to wait for mojo to send more. again, a couple extra feet of wire costs what? 60 cents?

if i do this agin i will try Mission.

Thanks for the help everyone. If anyone has any grounding tips (see my proposed scheme above) that would be great. while I wait for my wire...ungh.

[Resonator Guy]

Hey Ben, the nuts and bolts I got with mine (more nuts than bolts) did fit the tube sockets. I used them there and to bolt down a terminal strip I used for part of my grounds. One of the pots I received was broken, too. I did get plenty of wire though.

You will end up with a great sounding amp so keep at it.