I ended up measuring the PT with a voltmeter after I wired the primary taps.  The primary taps are the 2 on one side that say 120V.  The heaters and B+/HT are in pairs.  They are AC so it doesn't matter which connection goes to which as long as you get the heaters vs B+/HT pairs right.

Fuse doesn't have polarity, so either way is fine.

Shielded cable runs for the leads coming off the jacks and pots in the audio path.  Careful not to ground the shield on both ends.

I had a ground loop hum issue when fired up with my amp.  I ended up lifting the ground on the c-lator and that alleviated the problem.  The C-Lator measured fine on the scope by itself.

Hope this helps.  It would be helpful if the lay-out were more detailed.

Best,

James

Bump please...I'm really only curious about Question #3 below at this point.

Regarding the PT, I've identified which pairs of taps are for the heaters, B+, and input 120V.  Since these are all AC voltages, it doesn't make a difference which which tap I use as long as I get the pairs right, correct?  If someone could confirm this for me that would be great.

Thanks in advance for the help, I really appreciate it.

Hi Folks,

I'm in the process of building my C-Lator, and I have a few quick questions concerning some discrepancies between the layout and the pictures.

1) The fuse looks like it's wired in reverse from the way the layout suggests.  Is this because fuses do not have polarity and it doesn't matter?

2) I'm having trouble getting the perspective right for the transformer.  On the layout it looks pretty simple: 120, 0, 6.3, and 0 are arranged left to right if you looking at the chassis from a birds eye view with the faceplate on top and the rear on the bottom.  However, the pictures don't seem to show this same configuration.  Is there somewhere where I can look up the transformer taps layout?

3) Which leads should i use the shielded cable for?

Thanks in advance for your help, apologies if these are rookie questions!

Cheers,

James