Korting MT157 Reel to Reel Tape recorder

[Michael Maurice]

In around 1963, my father bought home a Korting MT157 tape recorder. Though we didn't know it it was one of the most advanced machines on the domestic market.

The tape recorder got used and abused, by us and fell into a state of disrepair, It had already gone back to the UK importers once for repair, A few years I attempted to replaced the drive belts, the new ones lasted two weeks!

A few years later, having purchased an Akai 4000DS, I again tried to resurect the Korting. I was always fascinated by this machine, I also always wondered (in my early youth) what the STEREO button was for, as depressing it always played the red track.

Let me explain a bit how this machine worked. This was a 4 track machine in which Tracks 1 & 4 were designated the LH channel or Green with tracks 2 & 3 designated the RH channel or Red.

As there was only one internal speaker this was connected to the RH channel when stereo was selected.

When I moved, I took the Korting with me, another try at revival got me some success, by now the Akai had gone wrong more times then I can remember and I'd since bought a Revox A77. The Korting then went into the Loft. Sometimes when I went up in the loft, I would look at it and wonder, could it ever be restored.

Then Ebay came along and I found I could get Kortings from the USA and Germany, and so I bought some, well several.

I decided not to tamper with dads machine, it had been so badly misused and slightly modified that it couldn't really be brought back to its original state.

By buying a German machine in a poor state, I swopped the mains transformer and motor to the USA MT158 only to find the machine still ran slow. Why because the difference between the 50Hz and 60Hz models is the rewind pulley! That sorted out, it was time to do some renovation work.

I found a source of belts in the US and after measuring the old belts, bought 10 of each. The brakes needed rebuilding which I did by stripping off the old material, lubricating and fitting cut slles from rubber grommets.

I replaced most of the capacitors on the two main circuit boards, after doing this the results were exquisite.

I have since restored a few more of these machines, which I keep in my workshop, (my wife wont let me have them in the house) Despite the poor sound from its internal loudspeaker, I still enjoy listening to my old tapes on them.

When we had some friends round for a barbeque, we listened to an old Alan Freeman Pick of the Pops on the Korting which was perched on a chair in the garden.

I'll now try and post some photo's

[Michael Maurice]

The head block and the brakes

[paulsherwin]

Originally Posted by Michael Maurice

When we had some friends round for a barbeque, we listened to an old Alan Freeman Pick of the Pops on the Korting what was perched on a chair in the garden.

Any chance of digitizing that tape Michael? I'm sure quite a few members would like it to play on old radios etc.

Best regards, Paul

[mikelect]

Originally Posted by Michael Maurice

By buying a German machine in a poor state, I swopped the mains transformer and motor to the USA MT158 only to find the machine still ran slow. Why because the difference between the 50Hz and 60Hz models is the rewind pulley! That sorted out, it was time to do some renovation work.

I don't understand how the rewind pulley affects the tape speed

Mike

[Michael Maurice]

Hi Mike,

If you look at the picture of the top of the machine with the covers removed, you'll see two belts, one is from the motor, the pulley of which is under the take up spool, it goes round the clutch bit of the take up spool and onto the rewind pulley.

The other belt is the capstan belt and runs from the rewind pulley to the capstan.

Korting manufactured two types of pulley, a 50Hz and 60Hz. The difference is in the ratio's between the diameters of the pulley. where the belts sit on. I'll try and photograph a couple of them so you can see the difference, but it may be a few days before I can do this.

[DOFFERY]

Hi Michael,

It looks from the pics. that the machine uses a Telefunken motor ?? If so be careful these are notorious as per the Tfkn, 75, 85 etc. etc. when the machines are left unused for sometime.

Doffery

[Michael Maurice]

The motor is actually made by AEG. Some versions used a Papst outer rotor motor.

What problems are there with these motors?

[DOFFERY]

AEG/Telefunken one & the same , motor breakdown , insulation problem, many Tfkn machines written off due to the motor problems.

Can't comment on the particular Papst system used on some Kortings, never met one.

Doffery

[reelguy]

Michael, Nice pics of the Korting M/c. . The original one you mentioned as being stereo probably needed to have been connected to an external amp to get the other channel.. You mentioned you now have several Kortings, Are they the same model ?. I have a Korting Model MT112 in the loft but cannot remember if it was working or not. Its a bit chilly up there at present so I will have a look when I get a chance.. I think it is older than your m/c though and probably Mono.. I must admit i prefer the older recorders and Akais arent all that interesting to me.. I have an Akai 4000DB which needs a playback head , I havent really looked for one of those yet.. Anyway, good to see your having success with your M/cs. Peter Reelguy

[Michael Maurice]

I dont know what an MR112 is, the MT118 was an earlier version.

The Versions I have are

MT118 stereo bought from Germany. Fitted with 3 core mains cable.

MT118 stereo, ditto the rest but has papst motor.

MT157 from UK (My fathers)

MT157 from Germany

MT158 same as 157 but made for US

MT158S has two internal loudspeakers and some versions had papst motor.

When I get the chance I will take more photo's and post.

[DOFFERY]

The MT 112 was a basic Korting , single speed 3. 75 ips, described as a dictating machine, although in appearance similar to later machines.

Doffery