Tefifon - in Stereo

This was just posted in a Swedish Facebook group dedicated to tape recorders: https://www.facebook.com/share/p/btULhoxn5HTDi5UC/ Someone saw a Tefifon in a radio museum somewhere in Sweden

I feel quite guilty that I listened to this video in mono!

I'm guessing you might talk about Dave Myers Memorial Bike Ride on your update. I just saw the video on the TM Extras (I'm subscribed) and read an article to get 'up to speed' on the particulars. I presume there was a group of folks on the bridge as they rode by. It's cool that you captured time-lapse video of the event.

Ah, I can comment again now. It kept saying I need to subscribe to you even though I was. Glitch in the system. There was a Bimbo box like that on Worthing Pier until it was refurbished a few years ago. Not been there for a while, maybe it's in a corner somewhere. There was a sign on it saying it's dead are.

This video was the perfect example of Techmoan. Fantastic!

I think this might have been mentioned before but maybe the project has progressed https://www.printables.com/model/68261-tefifon-replacement-cartridge-adapter

I don't think you could have rounded off the Tefi series better, Mat. 👍

Mat, at 20:39 the text overlay says that the joining of the ends of the tape was done under magnification. This is actually not quite true: there were register marks in the area of the tape ends for the actual joining and apparently the tape ends also clicked noticeably into the local press die during positioning. Enlargement was therefore not necessary for this work step. What was done under magnification, however, was the production of this local press matrix (the so-called “overlap matrix”, German: „Überdeckungsmatrize“): In this, the ends of the audio tracks were joined by hand under the microscope. These 2 mm of audio groove had previously been lost on the master tape (see the photo bottom left at 20:15), when the cut location was marked. Therefore, to produce an overlap matrix for joining the tape ends someone reconnected all the grooves by hand probably using a small milling cutter. The fact that these 2 mm of audio signal were missing and replaced by a random hand cut groove cannot be perceived by the human ear. Microscopes were also used for the follow-up inspection, but not for the main steps of mass production.

How about amplifying the signal with a RIIA ? MC input

Easy-to-remember advice about lubricating mechanisms: if it spins, oil it; if it slides, grease it.

I think by default this makes you, Mat THE Tefifon go-to guy for repairs! I don't imagine there is anyone currently alive on the planet who had had their mitts on the guts of this thing in over 60 years! (Unless you and Markus are the tip of the spear in Tefi circles and we are all unaware of the vanguard.) Mat, is this the oldest item item you have repaired? Not counting "easy" needle/cartrage swaps on old turntables.

WONDERFUL! I was just re-watching the first four videos in this series and BOOM, number 5 comes out. I thought it was very well done and really added to the series. I know in the second video you joked that you were "milking it for all it's worth" but that and every video really added information to the series. Unlike more common formats and devices you have covered, there really is a lot to dig into with the Tefifon. The only other format that might approach it would be the HiPac since it showed up in tape delay units and the BGM machine you looked at. In general I like the old BGM machines because they were so different. Anyway, GREAT JOB Mat!

Thanks for your efforts to play steteo TEFI for us! Too bad about the NOS cartridge. In the late '70s, our neighbor had a cool stereo system. He had quadrophonic sound inside, and a unique system in his 1969 Dodge Charger: a reel-to-reel tape deck mounted on two rails between the front seats!

At 1’30” I did notice the TEFI logo on that radio, but many viewers may miss that. Maybe you could put an arrow or something to point to it? Just a suggestion. Thanks for the video. It was excellently made.

Very interesting to see how delicate that stylus mechanism is. Seems like they could have made the parts a little bit beefier to help with durability. Good work, replacing it without damaging anything. You might want to add an overlay at 1:44 to clarify titles released vs units produced, when you say "17,000 KC-1's, 5,000 KC-4's, 5 cartridges". I'd love to see the Bimbo-Box someday. Looks like a fun predecessor to the Bandai Little Jammer system. The fact that it's got a Tefifon inside would just be icing on the cake. Is there any chance you can share the full song that plays on the end credits?

Great work on this, and thanks for the whole fantastic series!

• Wonderful video - nice repair, even though the cartridge turned out to be defective. • Hello there, huge Victorinox tool. 💜 • It's incredible how delicate and complex the mechanism interacts with all its components. I was impressed with the plastic/rubber on the cartridge... until you discovered it was too far gone to reproduce music effectively. • Why does the music make me feel like I should be in a festive German beer hall? • Tobacco smoke is officially to blame for all muck and staining on audio equipment from this era. 🚭 • Striptease Suzi 🤣 and Bimbo-Box... wow. • Incidentally I inadvertently obtained an LP within an eBay record lot "How to Strip For Your Husband." I haven't listened to it yet as sadly I don't have a husband ☹️. • Every time I listen to songs in anything other than English I enjoy them, despite understanding what is being said. I wonder if everyone feels this way... Nicely done and very entertaining/educational video. No matter your health diagnosis... take care and here's hoping all your tests are completed with acceptable results 🤍🤍

You've got Beethoven 9th Symphony, it was composed 200 years ago. Worth a listen! Thanks for this great video

This "Bimbo Box" looks familiar to me, I might have seen one as a little kid! And the Tefifon I even touched at the Exhibition "Grossmutters Radio" (Grandmother's Radio) in Horgen, Switzerland. Thanks for all the background on this system!

A classic video with a little of everything, repair, history, practical demonstration and humor. And of course thanks to Markus.

Very well done, Mat! I'm glad that some of my spare parts could be used, even if it's a pity that the rubbers in the cartridge have hardened... Your video is now the absolute reference for the functioning of the pickup of the KC-4. Very well explained! One curiosity that you didn't mention in the video might also be of interest to some: The contact force of the needle on the KC-4 was realized by a cone-shaped magnet! An absolutely curious and, from a technical point of view, somewhat absurd solution, because the force from the magnet was neither particularly constant, nor was it easy to measure and adjust. I suspect that this functional principle would not have made it into the final product under Dr. Karl Daniel... But hey, somehow it's also nice that the engineers at the time simply tried out all sorts of different things. And you are absolutely right about the number of people who have ever heard a stereo Tefi tape! Back then, perhaps even more stereo Tefifons were sold than stereo Tefi cassettes… All the best Markus

Great video! The Tefi must be unique among audio systems in that you have a cartridge playing a cartridge - the dual use of that word gave me pause for thought a few times!

This is a very nice coda to the Tefifon series. There's something meditative about watching your repair work, although I wouldn't be surprised if the whole process was a bit more complicated than it comes across in the video. The close-ups during the demonstration of the device had a nice touch. I also liked the nice variety of interesting facts conveyed in the video.

Good work, Mat! Seeing you put all of those fiddly little bits together makes me wonder if there’s any way for anyone to keep these machines running in the future. I suppose there may be folks out there who can replicate the perishable parts whether by hand or via 3D printing. Also wonder why so few Tefi titles came out without vocals—a guess is perhaps putting out more instrumentals would be a better way to sell to an international market.

Great video to end to the series. Really good to have learnt so much about an audio format I had never known existed prior to your videos.

A nice ending to a wonderfully produced series of videos covering an obscure, albeit fascinating audio tech. Thank you for giving this glimpse into a nicer time in the past. Side note: (little surreal) When I was young, (8-10 years old), my folks went over to Europe on a vacation. When they came back they brought me what I thought was the biggest, coolest Swiss army knife I had ever seen. I prized that knife, even though it was almost too big for my smallish pockets. To see you use a similarly engorged knife on the repair end of the video brought back some definite nostalgia. As always, great job.

Thanks Mat, i think in some ways you are the go to guy now for Tefifon! And we thank you for that.