Scott Masterpiece Schematic

[Joe Miller]

Just picked up a Masterpiece and need a good schematic. Anyone know where I can find one that is legible?
Thanks,
Joe

[David C. Poland]

Hi Joe.

I see Kent has not uploaded one to the set folder section. I'll contact Kent.

Riders Volume 14 probably the best diagram source for image clarity.

Or try Nostalgia Air which has  Riders images, too.  http://www.nostalgiaair.org/pagesbymodel/607/M0016607.pdf

Generally the Scott Masterpiece is pretty much a Super 12 with improved audio (push-pull 6J5 drivers for the 6V6 outputs). And 2 additional controls:  a two position sensitivity switch and a fidelity (treble) control.

Different speaker too, using the same speaker as the Scott Sixteen and early Phantoms using 6V6 outputs.

I have never seen any Scott technical info for the Masterpiece but the circuit diagram. Refer to the Super 12 info for alignment info.

-Dave

[Joe Miller]

Thanks Dave,

BTW I was going through the Masterpiece set I recently acquired (SN WW-83) and found a some oddities:

1.  The power supply appears to be the wrong one.  The set plug will not fit the PS socket.  Both are 7 pins but the spacing is different.  My PS has a pot between the set and speaker sockets but the picture in the documentation for the Masterpiece looks like a 120 VAC plug goes there.  See picture below.  What PS do I have?

2.  When checking the tube line up on the tuner chassis I found a 6F8 tube in the inverter position (rear tube on the left side column).  It is supposed to be a 6J5.  But, the 6J5 tube is a power tube with no grid cap, yet the tuner chassis has a grid cap connection for that tube and the 6F8 is a grid cap tube. How can that be?

3.  I am missing the AC cable that goes from the PS to the tuner chassis.  The PS has a 4 pin socket and the tuner has a 5 pin socket which I assume are for the power cable.  Haven't yet figured out why one is 4 pin and the other is 5 pin. Anyone know where I can find these 4 and 5 pin connectors?

Thanks again,

Joe

PS:  Kent do you have this SN?  I believe it used to belong to Eric.

[Joe Miller]

Maybe I have the improved Super 12? With the wrong power supply. Is there a schematic for the improved super 12 anywhere?

[David C. Poland]

Your amp looks just like mine, including the hum adjustment pot between the two sockets,

The correct amp has one 5U4 rectifier and a pair of 6V6s.

The AC power cord comes out the opposite end of the amp.

The 4 pin socket on the side is for the 2nd set cable, two wires used to carry one side of AC to the volume control on/off switch and back to the amp. Plug is a standard 4 pin and could use a base salvaged from a 4 pin tube.

The your sockets are riveted in place so appear original. One is the speaker octal plug and the other is the 7 pin set cable socket. Surprised the set plug does not fit the 7 pin socket.  Carefully inspect the plug to identify which  two pins are larger to match the socket if properly aligned.

[David C. Poland]

A possible point of confusion is the later Super 12's and the Scott Masterpiece both have 11 tube receivers.

So where are the 6V6 output tubes located?

The 5 pin socket amp socket you mention would be correct for the Super 12 speaker 5 pin plug. And,  the Super 12 has  octal  SET socket. Whereas the Scott Masterpiece has an octal SPEAKER  socket.

The 14 tube Scott Masterpiece has a 11 tube receiver, 6 controls and 3 tube amp/power supply.

The Super 12 has an 11 or 12 tube receiver. The 12 tube 1st version has the power transformer and rectifier on the receiver chassis - the only single chassis Scott made in the 1930's. The later version has a 1 tube power supply holding the power transformer and rectifier tube. The Super 12 always the pair of 6V6's in the middle of the back with no tube shields. Both the 1st and 2nd version super 12's have 4 controls (plus tuning knob) 

The 3 rd version of the Super 12 (I have one) has two additional controls making it look like a Scott Masterpiece at first glance from the front- BUT HAS THE  6V6's ON THE RECEIVER. The Masterpiece has 6V6's on the amp.

So to be sure look for the pair of 6V6's at the back of the receiver - if found, it is a Super 12, If not, it is a Scott Masterpiece. (Tube numbers are also embossed on the tube sockets)

Hope this helps.