Neufeldt & Kuhnke


In 1899 Hans Neufeldt and Karl Kuhnke founded the Kiel company Neufeldt & Kuhnke. Until 1936 the company stood for excellent and very durable technical products. Then in 1936 the name was changed and the previous brand was forgotten. But in 2020 the brand will restart with the same focus. Committed to the spirit of NuK, we pay attention to sustainability in production and the selection of materials.
See also our additional article on this topic.

Neufeldt und Kuhnke NUK30 Radio
Bildquelle: 32bitmaschine / CC BY (

The NuK restart in 2020

MoRobo has established itself in the areas of automation, IT consulting and IT service. It was clear that this name did not match the modernized vintage furniture and appliances.

We were looking for a brand that clearly reflects what has been created here in Kiel since the end of 2018. This brand should also fit into the time of the material that is used here. In short: A brand that was active from the end of the 19th to the middle of the 20th century was sought. Neufeldt & Kuhnke was certainly known to us and many others, too, for its excellent devices that are already in stock here. So we researched what the current trademark rights are like. After we found out that no one claims this mark, we carried out the registration for the appropriate Nice classes. Therefore, the Neufeldt & Kuhnke brand as a word mark in now owned by MoRobo since September 2020.

A brand needs products

First we converted a Telefunken music cabinet into a house bar. That worked very well. However, Hi-Fi devices are often still built into these cabinets. We test these devices so that a collector can enjoy them again. We try to achieve a zero waste balance. For us, this means: Everything should, if possible, be reused.

The Telefunken music cabinet under renovation
The Telefunken music cabinet during remodeling.

In the said Telefunken music cabinet was a record player from the same company. To test this you need an amplifier that has a magnet connection for older turntables. We own a Pioneer LX-440A. This receiver has the required connection. Now the story gets exciting: The LX-440A has very special speaker connections for which there are no more plugs.

From upcycling to development

Any attempts to make a reasonable connection to speakers with normal plugs have failed. It quickly became clear to us: We had to develop our own connector!

Speaker connections on Pioneer amplifiers / receivers of the SA / LX and SX series.
The speaker connections of our Pioneer LX-440A

For this purpose, we first took the dimensions of the connections and printed a first dummy. We put copper bars in there. That way we had a rough model of the speaker connector.

Plug-in dummy for checking the dimensions of the future connector.
Check the dimensions for fit

The first dummy can now be seen here.
What luck: It fitted immediately!
On the basis of the dummy, a first drawing for a loudspeaker connector could be created.

The first 3D model for the prototype

Above we can see the first 3D model for the Pioneer connector. The holes for the M4 screws are already set here. There is also space for the rails and 4mm² cables.


Based on this model, the first prototypes were produced in the 3D printer. The screws are still simple one that are comparable to an M4. Here we see the prototypes with the cables attached. In fact, the first version worked fine.

LSLX-1 prototypes
The first version of the LS connector as a prototype
Adaptation of the LXLS-1 prototype to the amplifier
Adaptation to the amplifier. Is everything also right?

Fine tuning

Other models followed. A plus sign to mark the phase should follow, followed by a minus sign. We also wanted to place the company logo.

Voxelizer model of the LXLS-1
The idea with the added elements turned out to be a failure

Initially, the letters of the Neufeldt & Kuhnke logo were simply placed on top. However, it quickly happened that these simply fell off. Another solution was needed: Indentations are significantly more stable than attached elements. So we decided to leave out the elements.

The final model

The final version of the LSLX-1 as a 3D model
The final version has indentations so that the plug can also be polished and everything lasts for a long time.

End of work

Here are the finished connectors. Next to the phase and ground markings we decided to use separate colors as well. Here is red for the right channel and blue for the left. The letters R and L also work great in English. (blue = left / red = right)

Final version of the speaker connector LXLS-1
The final version of the speaker connector now has separate colors
Neufeldt & Kuhnke LSLX-1 on the Pioneer LX-440A
Neufeldt & Kuhnke LSLX-1 on the Pioneer LX-440A

The plan to build a house bar out of a music cabinet ultimately led to a completely new product that we would never have thought of.

This was the little story about the rebirth of Neufeldt & Kuhnke in Kiel. Sometimes the original plans turn into completely different things, but we are very satisfied with that.

And here you can buy the connector pairs:
Part number: LSLX-1
EAN: 644221278994
Pioneer part numbers: AKM-003, K72-007