Magnecord INC Historical Archival Material Part 1

I almost cried for joy at finding this new addition to your Magnecorder pages!!

For the last two weeks, I have been in process of trying to restore my Dad’s early Magnecorder PT6-A (PT6-AH transport and PT6-J amp unit) back to working condition. Dad was an organist and choir director, and used this machine into the 1970s, until Parkinson’s disease robbed him of the last 20 years of his life.
He left me hundreds of tapes made on this machine which I want to archive and transfer to digital (not because it is better, but because I want my kid and family to be able to easily play these precious recordings of family events and dad’s music.
He even recorded what was billed as “the last Steam Train in Georgia” in September 1959 with the PT6 and the original tape will send goosebumps up my spine 52 years later!
I have replaced all capacitors, and most resistors, but still have hum which increases with gain/volume knob in amp. This is happening with tape transport unconnected so noise is originating in the amp unit, but I don’t know where. Any thoughts or suggestions?

Also, any hints of where I might find new idler wheels? The tape transport is EXTREMELY noisy due to the old tires being bad. It does work, but just awful noisy. I have just purchased two more machines off eBay this week, which I have not yet seen but bought them to have some spare parts. May be able to restore them also once I find the trouble with my original one.

Looking at the factory pictures is neat! Wish I could step through the time portal and go grab a few of those brand new parts!

Do you know anyone else who loves these machines and who may have some parts?

Hi,
As a (European) collector of Magnecord products and interested by the company’s history and contributions to the art of sound recording I greatly appreciate the rare informations and documents you provided here. (especially the photos of the early Magnecord factory,my deepest thanks to D.Boyers for making these available to us).
Now I’m eagerly awaiting for Part Two of this series,hope it will come soon… with more original pictures and rare documents. Magnecord’s history certainly need to be better documented on the web because their products were innovative,of great historical significance and of the highest quality, some being still in service today nearly 60 years after they left the factory… the PT-6 series were probably the longer lasting tape transports ever produced , a perfect exemple of clever and efficient engineering.
Thanks again for your work,
Nick

I am in the middle of refurbing our old PT6 series (~1954) 1/2 track transport and electronics (miniature tube version with 12AX7, 12AU7, 5879, 6AQ5 and 5Y3) used until ~1961 and stored since then. I did not replace caps but instead reformed all of the electrolytics by applying rated voltage through ~2K and ‘soaking’ until leakage current dropped to the 10’s or low 100’s of microamps .. which took as long as 36 hours. All caps then measured at or above rated capacity.
Had to replace the selenium bridge stack in the 12.6 volt DC filament supply (very poor front to back ratio) with a silicon bridge in series with 5 ohms to drop the filament voltage to slightly over 12.6 at 125VAC line voltage. Amp shows no noticeable hum.
Just sent off the main drive and take up reel pucks to Terry’s Rubber Rollers for rebuilding as they had hardened and were slipping. Rest of transport looks good and heads still appear to have useable life.
Some of the tapes I need to digitally archive (voice recordings from amateur radio contacts with the Antarctic) were done at 3.75 but the EQ network was 7.5 (the amp only had the 7.5/15 plug in EQ network. Guess we didn’t realize it at the time since we didn’t need anything above 4KHz.
Managed to clean up the portable cases (which had mildewed somewhat) to the point where they have that ‘leatherette’ smell that I remember when they were new. A fine piece of vintage audio equipment which Magnecord engineers could be justly proud of.