[morzh]

Do I understand correctly that some of the 16 radios (like those tombstone types) had the same chassis as 116?
The one without capacitor can "Philco 20" style? And if true then in fact 116 is a 16 with acoustic clarifiers?

[Ron Ramirez]

The 4-band model 16 sets (codes 125, 126, 127) are very similar to model 116...but there are many differences as well.

Both look nearly identical above and below the chassis.

Model 116 adds a fifth band (long wave), plus a larger dial scale and larger escutcheon.

Model 116X, the console that uses Acoustic Clarifiers, uses 6A3 output tubes. The 116B, as well as all 16 sets, use 42 output tubes.

[morzh]

Thanks Ron.

I was just looking at that chassis of 116x on eBay and the tombstone 16 and realized Ii could not tell them apart so I decided to ask.

[Arran]

So did the 16 and 16Bs both use push-pull #42s? Why did Philco use 6A3s in the 116s? It seems sort of a nuisance that they would produce essentially the same set with a different power output stage? Especially now that 6A3s are much harder to find then #42s, I think that the Philco 116s were one of the few sets that used 6A3s, other then that they were mostly used in jukebox amps. A model 16 is one of the sets I am keeping my eyes open for, especially one of the slated top tombstones, but a 16H, 16X, or 16L would also be welcome, or a 16MX if one exists. I remember my uncle used to have a 116B, one of the late versions without the shoulders, that's another worthwhile set even though it only has the 8'' speaker in it.
Regards
Arran

[morzh]

I need to find out what Kirk gave me. It is a console 16.

[Arran]

Mike;
If it is a fully shirted console, with no legs, then it's probably a 16X, the speaker board will also be on a slant.
Regards
Arran

[Ron Ramirez]

Mike

Since it is a 4-band 16, it is a 1935 model.

16L: http://www.philcoradio.com/gallery/1935a.htm#b

16X: http://www.philcoradio.com/gallery/1935a.htm#c

[Ron Ramirez]

Arran

There was a 16 chairside in 1935, it is the 16RX: http://www.philcoradio.com/gallery/1935a.htm#d

As to why Philco used 6A3 tubes in the 116X, 116RX and 680, you're asking a question that only someone who in the Philco R&D department in 1935 could answer, and they're all gone. I would guess that the intent was to offer something with a higher power output that what was achievable with push-pull 42s.

Although, I looked up the 42 in the NJ7P database and I see that you could get up to 19 watts out of a well-designed push-pull amp using 42s in class AB2. I also looked up the 6A3, and you could only get 15 watts max out of a pair of those in class AB1.

The 6A3 was probably something new that Philco used for the 1936 season in their high-end models. I do not know what year the 6A3 was introduced but I would guess it was sometime in early 1935.

Philco switched to the octal-based version of the 6A3, the 6B4G, in the 1937 season for the 37-116 and 37-690.

[morzh]

I think mine is 16x - it has the slanted speaker board.

[TA Forbes]

Depending on how you drive the plate V and bias of the 6A3, you can achieve considerable power out. I have heard of modern tube amps that use 2A3s in PP that are putting out 40 W power. I believe my Sparton 1568 puts out 20W with two 2A3s and 360V plate, 64V bias. Additionally, the Sparton has iit's own power xfrmr and 5X4 rectifier dedicated to it's 2A3 output tubes.

(The 2A3 and 6A3 are the same except for the fil V)

BUT back to the original question.... from what I have read there were some folks back in the '30s that believed that a triode produced a better, clearer sound. I believe that this resulted in the many sets made by many producers in the late 30s that featured 45 and 2A3 tubes in sets that had 6V fil V on the rest of the tubes, except perhaps the rectifier. Later 6V fil triodes like the 6A3 and 6B4 made is easier (and cheaper) to d this, as the power transformer utilized would not require a 2V fil winding.

[morzh]

I once (when building transistor amps) tried to see how much power I need for my 100W/channel amp to sound loud enough so I would not need that much.
Turned out 2-3Watts did it.

So, why do you need all that power?

Yes, we all know you need to handle peaks in order to do HiFi sound, and this is where your power and your dynamics come together. However if you are playing at 2-3W your peaks will be possibly at 8-10W. And if you are into listening alone, in a designated room, you will not even need that much.

This "quest for power" - even though I was a part of it at some point, but it was more of a sport to me than the real need. When I realized I no longer wanted to brag about how much I can put out, all I needed was very little to listen to my classics and jazz.

[Ron Ramirez]

From 1933 until 1938, Philco connected their 42 tubes as triodes in most of their push-pull output circuits, as well as using triode-conected 42s as driver tubes.

Tom, you're right regarding the 2A3 and 6A3.

As for the "need" for power, no, one does not really "need" say, 100 watts per channel. I have a Marantz 2215B stereo receiver that is looked down upon by some because it puts out "only" 15 watts per channel. But those 15 watts per channel sound pretty doggone good...

And the 15 watt output of a 37-690 or 38-116 sounds pretty good, also. The 37-690 uses the octal version of the 6A3, two 6B4G tubes in push-pull. The 38-116 uses 6L6G outputs.