Series filament amp

[Stuff4bikes]

I have this little Packard bell amp......I DON'T USE IT WITH MY GUITAR........AND I POWER THROUGH A CURRENT LIMITER WITH AN ISOLATION TRANSFORMER......I use the amp to test unknown output transformers....I ran my Packard bell console record player through the amp and it sounded decent....

So here is my question.....
How would you wire a three prong cord to this? And after i got the amp I changed the 50C5 cathode resistor and added
25/50v cap. Originally it was soldered to the center post of the output tube but I TRIED grounding it to chassis and it didn't like that. Just curious

[PRR]

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[Stuff4bikes]

So just leave the amp as is and add the 3 prong cord.....no need to run the heaters through the neutral?

[acheld]

Looking at PRR's schematic:   at the end of the line of series heaters, schematic shows current going to ground, which is shared with secondary "neutral." 

[Stuff4bikes]

I noticed that about 5 seconds after posting...jumped the gun when I didn't see a "tail" coming from the filaments.