Super 12 Late Version Tube Layout

[Buzz Stone]

Does anyone have a tube layout for the later version of the Super 12 with the rectifier tube on a separate chassis. The layout on the main chassis is not the same with the rectifier tube moved off of it.

Thanks!

[Kent King]

Well, that is an interesting problem! I just looked at my manuals and documents. Scott even created a "new" owners manual with a picture of the late chassis on the cover - but EVERY image inside the manual is the early set, including the tube layout. So they never created a document showing the later chassis (at least I do not have anything). I do have a late Super XII myself, but it is in my Brentwood chairside cabinet, which is a bear to get in and check. I'll try to look at it this weekend and get the tube layout if someone else can't get it before then.

Kent

[David C. Poland]

My experience with a later version with the 1 tube power supply (with the usual 4 control shafts) was the same tube layout. Look for tube numbers embossed on the tube sockets.

But the really late version with the additional 2 controls may be another matter. I had one with the wafer type socket construction and had no embossed tube numbers. I never had time to fully explore it but there were a couple unexpected tube numbers actually installed that I was suspicious of. 

Unless you can find/borrow another Super !2 receiver for side by side comparison, suggest you compare the diagram with your receiver  socket by socket. 

The 2 additional controls were:

-  a radio/phono switch (was removed from the band switch to make room for the ultra high frequency band needed to receive the audio for the pre-war experimental TV broadcasts which were video only).

- addition of a variable sensitivity control 

However - here is nothing about these two control enhancements for 1940 Super 12 that seem to me would have required Scott changing the tube layout. Although the extra sheet with the owners manual did note the upgrade to the "more rugged" 5U4-G  for rectifier instead of a 5V4-G.

This 6 shaft model Super 12 was short lived, soon giving way to the 14 tube Scott Masterpiece with the enhanced audio section, and 6 control shafts. Indeed - compare the owner manual's tube line up of the Super 12 with the 14 tube Masterpiece. Same tube line up but with the addition of a separate 6J5 Inverter and a 2 tube push-pull driver for the out put tubes (which were relocated to become a 3 tube power pack).

Hence - I regard the 14 tube Masterpiece as a "souped up" super 12 - and mine sounded really impressive  feeding a CD player into the phono input.