Tube console amp. Montomery Wards Airline Help?

[CA2010]

Picked this up today. Anyone familiar with this amp? I'm not finding anything. Any information would be appreciated.

Thanks,

 

[macgolf]

Wells-Gardner made many of the amps for MW. Is there another label that has a WG model number? Yours looks to be newer than my 62 that has an option for a MPX unit. What is the tube compliment? I enjoy my 6GW8/ECL86 powered W-G unit.

Mark

 

[cademan]

It looks to have a 12AX7 type of tube up front and the output tubes are most likely 6BQ5/EL84 so single ended stereo.

Looks like one of the output tubes is broken and the other one is missing.

 

[CA2010]

Thank you for the response Mark, your help on the Wells-Gardner turned up a good thread. In response to the question of what is the tube compliment I'm posting this image from the linked AK thread. https://audiokarma.org/forums/index.php?threads/need-help-identifying-tube-amp.817878/page-3


Cross reference in detail later but its looks very similar.

Cademan, thank you for looking. Yes the tube is broken and the other missing.

 

[macgolf]

You're welcome. All of my tubes were original to the unit, and were labeled for Wells-Gardner. Are there any tubes that you can see writing on to verify if it is a WG unit? Here's a not very crisp pic of one that came out of my unit

 

[century tek]

Wow, I was thinking 6BQ5 before I saw the tube chart. A 6BM8 is about half of a 6BQ5 but it also comes with its own triode.

 

[CA2010]

Just checked the tube compliment. Changes are in reference to the drawing above.

V7 is a 6EU7 not the EM84 as drawn
V6 is a 6BJ8 not the 6BN8 as drawn

As for Mark's question of origin. They all are branded "ULTRATONE" some made by RCA in the US and some in Great Britain and one by Philco.

Thanks for the thoughts and conversation.


6BJ8 "ULTATONE" made by RCA in the USA


6AU6 "ULTRATONE" made in Great Britian



6C9 "PHILCO COOL CHASSIS TV" made in the USA

 

[gadget73]

There are bunch of Ultratone brand things listed in the Same Photofact index. They may well have been the OEM.

 

[macgolf]

Looks like you're getting closer to finding who made your amp, and in the process adding some great information to this site.

V7 is a 6EU7 not the EM84 as drawn

So the tube in the EM84 socket is a 6EU7? Can you find a tube identifying stamping on the chassis, for that location? Based on the location and in your photo, that appears to be the perfect spot for a EM84 which is a tuning indicator tube. The hole in the your face plate doesn't appear to be large enough to maximize use of this type of tuning eye tube, though. The 6EU7 is a preamp tube.

Mark

 

[CA2010]

Looks like you're getting closer to finding who made your amp, and in the process adding some great information to this site.



So the tube in the EM84 socket is a 6EU7? Can you find a tube identifying stamping on the chassis, for that location? Based on the location and in your photo, that appears to be the perfect spot for a EM84 which is a tuning indicator tube. The hole in the your face plate doesn't appear to be large enough to maximize use of this type of tuning eye tube, though. The 6EU7 is a preamp tube.

Mark

Nope, There are no tube ID stamps on the chassis. Perhaps the incorrect tube got placed in there at some point. With that assumption. What might the rectifier tube be? Its gonna be half of

 

[century tek]

No rectifier tube. It uses solid state (diode) rectification.

 

[gadget73]

the front panel is a bit strange here. From what I can see of the faceplate, it has a nice window where I'd expect an eye tube with a shroud to sit. It appears that it has a black panel with a single lamp in that spot though. It may not run an eye on this specific model, but its not impossible older or other brand versions of this did. Could be the 6EU7 is driving the lamp as a stereo indicator.

you'd really have to check the wiring on the bottom to see what makes sense. Easy one is the heater wiring. 6EU7 has heater on 1 and 2. EM84 is 4 and 5.

 

[Tom Bavis]

6BJ8 and 6BN8 are somewhat interchangeable, same pinout but different amplification factor. Chassis is extremely close. Transformer numbers can include a date code,

The Sams folder referenced in the earlier thread should be close

 

[CA2010]

Thanks All,
I have looked at the Sams. Does Sams have a preview button I'm missing. I'm only seeing the option to download and I'm not sure which one. The output transformers numbers are: 1225 followed by 9496352. The power transformer number is: 1121 followed by 9496401

If the date codes follow what I've seen before it places the OT in 52 week of 63, and the PT in the 1st week of 64. So early 64 build?

 

[CA2010]

Pinout for the 6EU7




Pinout 1 location



Looks like pin 1 and 3 are chassis ground

Pin 2 is connected to the Loudness pot through a 470k ohm and a cap

 

[gadget73]

that doesn't make sense for a 6EU7, the heater wouldn't work. Doesn't make sense for an EM84 either, pin 2 on that does nothing and pin 1 is the grid. 1 would need some negative DC voltage source in order to work, and cap-coupled doesn't work for that. I don't see a 12A*7 working either, you wouldn't ground both the plate and the cathode. It just wouldn't do anything.

 

[CA2010]

Here is the EM84

looking at pin 1 and 3 on the EM84 shows V7 is not wired this way.

 

[FlaCharlie]

Here's the Sams that Tom mentioned in the other thread:

 

[CA2010]

This could be newer model using a leftover chassis from when Valve 7 (V7) was used as the tuning indicator. Here are pics showing the use of "black out" felt to cover hole. My unit has its separate tuning indicator.

View from inside chassis showing the tuning opening above Valve 7 (V7). Note the location of the "tuning indicator" it is shown as a reference for the outside view. Please forgive if this is not the standard noun used to describe this.

 

[CA2010]

FaCharlie, Thank you for the posting the Sams link that Tom mentioned. I have taken a look and cross referenced the Tubes. The Sams schematic appears similar to the drawing earlier in the post. However, the tube ID numbers are different in the schematic. (again when compared to the earlier drawing.) For clarity moving forward I have referenced for schematic tube ID moving forward. attached is a pic showing the tube location.



SAMS Photfact folder set 722 folder 5 airline models GAA-2014A / 34A / 44A / 54A
Thank you all for the help

compared to schematic:
V1 is a match 6C9
V2 is a match 6BE6
V3 is a match 6AU6
V4 is a match 6AU6
V5 is different, the schematic is listing 6BN8, I have a 6BJ8
V6 is a match 6EA8
V7 is different, the schematic is listing EM84, I have a 6EU7
V8 & V9 schematic list 6BM8, mine are missing / destroyed.