My Gulbransen Upright Recordo player has a Motor Player Pump type H.
I don't know how this is related to the pump found in some Duo-Arts,
but my player hasn't missed a beat since I rebuilt it 30 years ago,
and I did almost nothing to the pump then.  It's true that one can
hear the whine of the pump as it works up to operating speed, but
once the music starts, it's not noticeable.  So not all Motor Player
Co. products were junk.

When I first purchased my Gulbransen, I found the original instruction
leaflet still attached to the motor case and I loaned it to Vestal
Press so that they could reproduce it.

The recent posts on this subject have reminded me that maybe I should
give my pump the once-over.

John Phillips in Hobart, Tasmania.