Paramount Build Questions

[JP]

At long last, I'm finally getting time to spend on building up my Paramounts.  (Note to self - don't plan for having a lot of free time right after the next kid is born!)  Anyway, to the topic at hand...

I have a few questions:

• In the attached four_pin_socket.jpg, you'll see that the four pin socket that I got is different from the one in the manual.  Is this the correct part?  How do I tell align the larger pin holes when all are the same size?  (I'm writing this a few days later, and I seem to think that mechanically it doesn't even fit, but I'll have to double check that again tonight.)
• Can people confirm that there is no plastic spacer between the PT-4 and the top of the aluminum plate?  I installed a spacer between the PT-4 and the bottom of the plate, per the instructions, but I thought I saw one on the top in the photo in the manual.  Just wanted to confirm before I move forward.
• The screw hole for the PC-2 is hitting the hum potentiometer, as seen in the attached pc-2.jpg.  I'm just planning to bend this a bit, but wanted to post this photo so that the bottlehead team can make a note of it for any future products.

[Chris65]

Hi,
Yes, the 4-pin socket is correct, Bottlehead have obviously changed the part since the manual was written. You'll need to look at the topside of the socket to see which holes are the larger ones & then align it as per the instructions.
In my recent BeePre build I found the socket too large for the hole in the chassis, you may have the same issue.

Not sure about question 2, there's normally a nylon shoulder washer that fits into the bottom of the transformer & sits between the transformer and the chassis plate.

[fullheadofnothing]

The power transformer is isolated from the top side of the chassis with the nylon shoulder washers  they are shown in the second picture on page 43, but the text does not clarify.

The picture of the choke looks like it may not quite be aligned, since the nuts aren't in place. If it doesn't seem like it will snap into place when secured, you can carefully trim the flange with tin snips or file it to give more clearance.

[Paul Birkeland]

That tube socket is the correct part.  If you look at the top side of the socket, there are two pins that are obviously a bit fatter than the others.

If this is tough to see, then you can take one 4 pin tube out of its box, note which pins are the fat pins, then look for the only way that the tube will fit in the socket.

As far as the hum pot goes, we ended up changing parts somewhere along the way.  There isn't much harm in those two touching, but if you have a file laying around, you can file that choke mounting tab to add some clearance.

-PB

[danox574]

How'd you get that 4 pin socket to fit?  I have one with my Paramounts that just won't fit the panel - and seems like it's a long way from fitting.  I've turned the whole edge silver trying to get it in, and I've never even been able to start the socket and have it sitting inside the hole, one side is always unable to seat, even when the part inside is just 1mm deep or so (trying to insert it as square as possible).  The other socket in the kit fits both panels fine.

I'm a tad nervous about trying to ream that hole out, one slip with a tool and I'll have a forever visual reminder.

What's the best way to go about this?

[Demsy]

Look for a piece of dowel or round broom stick slightly smaller than the hole, about 30cm long. Wrap sandpaper 120-180 grid around it. Put it in the hole and try turning the dowel with sandpaper evenly around the hole. Try to fit the tube socket regularly. Once large enought you can wrap a 400 grid sandpaper around the dowel and sand the enlarged hole smooth.
You can use rougher grid sandpaper at the beginning if the you need to remove a lot of the base material, something like 80 grid. If you are using the original aluminium base plate, it won't take that long sanding it. Just turn it evenly around the hole and the end result will be good.

[RPMac]

Put a rat tail (round) file in the hole and go around the edge of the hole like you are stirring a cup of coffee holding the file firmly. This should clean up any burrs left in the manufacturing process. It's slow, but takes a lot longer to screw up the hole.

Depending on your experience, you can do the same using a 3/8-1/2" drill bit in a drill. With the drill running, use the side of the drill bit against the edge of the hole. The trick is to keep moving in a circular motion around the hole with light pressure. Clamp the plate to your work table or in a vise using pieces of wood to protect the top plate.

[Doc B.]

Or you can contact us and request another socket.

[thdewitt]

I am just getting around to building my Paramounts and just encountered the same problem.  The 4 pin socket is too large for the hole.  Will reach out to Bottlehead tomorrow for a replacement.