Philharmonic Factory Wiring Error?

[Joe Miller]

I am currently restoring a 30 tube pointer dial Philly.  I started with the Amp and found what I think might be a factory wiring error, but not sure.  Here's what I found:

The actual wiring of the C71 500 mfd micas and the R42 (250,000 ohm) resistors were not symmetrical as I expected. When I looked at the bottom view drawing (Riders 14-47) it matched they way the amp was actually wired (not symmetrical). But the schematic (Riders 14-49) shows these components wired "symmetrically" as I expected.

I think the schematic is correct and the bottom view and actual wiring are incorrect, so I changed the wiring to match the schematic.

Has anyone found this same "wiring error" on the amp chassis? Looks like it came that way from the factory, so am I missing something here?

Here's the link to the Rider info. http://www.nostalgiaair.org/Resources/610/M0016610.htm

Thanks,

Joe

[Norman S Braithwaite]

Yep!  That wiring error is present in about half of the Philharmonic power amplifiers.  It probably resulted from a miscommunication between the fellows designing the wiring and the fellows wiring the set after a design change to physical layout of components had been made (and only half implemented).  The error does not significantly affect performance of the power amplifier.

Norman

[Joe Miller]

Thanks Norman

Joe

[Joe Miller]

I've moved on to the speakers and am afraid I may have a problem.  The speaker that came with the set included a 15 inch pedestal that appears to have been restored (looks like a good job).  Re-coned and repainted.  (see pix)

The model number is Y2F318, Part # 2553, but the plug has the two larger pins adjacent to each other rather than separated by two or three smaller pins.  So it won't connect up to the amp chassis. I suspect that I have the wrong speaker for this Philly?

What do I have here and can I make it work?

I also have the tweeters and their plugs fit the mating ends on the pedestal speaker.

Thoughts?

Joe

[Joe Miller]

Here are the pictures.

[Norman S Braithwaite]

Did you get the speaker with the chassis set?  There are a couple odd features about the speaker.  First is the plug that you have noted.  But also, the socket for the tweeters is usually mounted on the pedestal base like a tube socket.  The pedestal base on your speaker is not even punched for the tweeter socket and a separate cable with a tweeter socket has been added.  These speakers were also used in some organs but with different field and voice coils.  What is the DC resistance of the field coil?  Also, what is the spacing between pins of the tweeter plug that mates to the socket connected to the woofer?

Norman

[Y2K Bruce]

Hi Joe-I checked all of my Philly speakers and they all use the plug you DON'T have with the 2 big pins separated by several small ones. The one different Philly I have uses a Jones plug for some reason. It's an AM/FM 33 tuber.

Maybe your amp is not from a Philly but perhaps a Phantom ??

[Joe Miller]

I'm sure I have the Philly amp.  I got the set (tuner, amp, speaker, cabinet from Eric)  I'm going to take some measurements and pictures later tonight to answer Norman's questions.  I hope I can make this work, but not sure yet.

[Y2K Bruce]

Hi Joe- I have a 30 tube Philly right now on my bench (aka my LR coffee table) and I just looked at the chassis plug (that goes into the amp) and discovered it has the exact plug you have on your speaker with the 2 fat pins side by side.

Maybe you should check the female plugs on your amp and see what they are set up for.

[Norman S Braithwaite]

I don't believe that the Phantom ever used a pedestal speaker. Also, the Phantom used the same odd speaker plug employed by the Philharmonic, a Jones plug, or a four pin plug for the optional four unit speaker system but never used the AW-23 speaker plug. Possibilities for Joe's speaker include the speaker being built up from available parts, the speaker being an accessory speaker for a special AW-23/27 or Philharmonic installation with booster amplifier, or the speaker being an unusual variant and having the plug swapped out. I have swapped out the hard to find Philharmonic speaker plug and socket with the more easily obtained AW-23 speaker plug and socket for one Philharmonic restoration (having a flattened original speaker plug) but the speaker I modified had the correct tweeter socket. I suspect the first possibility for Joe's speaker. The requested information will be helpful in identifying the nature of the beast.

Norman

[Joe Miller]

Here's what I have found so far:

Tweeters (see picture):

1.  Model number is Q8PC3330 6

2.  One has an in-line capacitor (like the schematic indicates)

3.  Pin spacing is about 1/2 inch

Pedestal Speaker (see picture)

1.  Pin spacing is on a diameter of about .70 inches, appears to be same as socket on chassis, except for pin configuration (large pins are adjacent)

2.  Found two power resistors (500 ohm and 1500 ohm) in series taped up with black tape

3.  Also found large transformer, assume it is the audio output transformer, but one of the three leads on one side is taped off.  The schematic calls for center tapped primary and secondary.  Need to troubleshoot this some more

4.  VC measures just under 8 ohms

5.  I started reverse engineering the wiring but have not finished.  I believe the FC is 5K ohms, but it doesn't appear to have a center tap on it like shown on the schematic.  It is connected to pins 3 and 4 (where pin 1 starts with the most clockwise large pin as in a tube socket)

6.  I will try to finish the reverse engineering on it tomorrow.

[Joe Miller]

Bruce,

Its interesting that your 30 tube Philly has the same plug (but obviously the correct socket) as my speaker.  That is somewhat comforting.  Mine has some additional mods (see above) that I haven't figured out yet.  One solution might be to convert the speaker plug to mate with the chassis socket I have, but not sure.  Also not sure if I can find a replacement plug.

[Norman S Braithwaite]

Joe:

Bruce was describing the set (tuner chassis) plug, not the speaker plug.  The Philharmonic tuner chassis plug is 7-pin with two adjacent large pins.  The Philharmonic speaker plug was different to prevent plugging the tuner and speaker into the wrong sockets.  The AW-23 used two similar 7-pin plugs both having adjacent large pins but the two plugs had pin spacings of different diameters.  Your speaker has many differences from the original Philharmonic speaker.  I am now very confident that your speaker was built up from mostly non-Scott sources.  The tweeters appear to be the coaxial mounted tweeters from Scott 800B speakers.

Norman