The tuner says Symphonic. This was a known brand in the 50's. As a child, I had a Symphonic suitcase record player which had a single ended stereo 6BQ5 amp inside. See the symbol.
I currently have a Symphonic series string hot chassis 35C5 push/pull amp from an old mono record player.
Of course I understand the dangers of hot chassis' so its more of just added junk to my hoard...er.....collection.