Play & Play pair with XLRs: 1970s Telefunken NFLÜ 325 600ohm line transformers -

Description

Pair 1970s Telefunken NFLÜ 325 line transformers
This listing is for one pair (Quantity: 2) of these hefty line transformers.
This type was
mainly used in state-owned broadcasting houses for high level audio lines interconnecting studios.
- hence the massive build.
Each transformer weighs 2.2lbs
The transformers measure flat
within +/-0.3dB between 20Hz .. 20kHz.
Specifications:
Independent secondary windings:  2:1, 1:1, 1:2
DC resistances:
Primary        13 ohms
Secondary   2:1      8 ohms
Secondary   1:2     26 ohms
Secondary   1:1     14 ohms
Impedance:                      ca. 600 ohms.
Dimensions:                     3.1 * 3.7 * 1.7      (metric: 8 * 9.5 * 4.3cm)
Weight:                             2.2lbs (1kg)
Additional technical information:
These are 600ohm line transformers.
Connecting them to modern high impedance studio gear will give a gentle shelve-like treble boost.
Around +4dB @ 20kHz.
For a flat frequency response, strap a 600ohm resistor across the output windings.
I've measured the Telefunkens to be within +/-0.3dB from 20 to 20kHz in conjunction with my Antelope Orion converters with this terminating resistor installed.
The treble boost effect of the Telefunkens is very nice sounding, not unlike a good passive inductor EQ.
You can play with this by using a 5k pot in series with a 300ohm resistor across the output winding.
This will then act as an adjustable high shelve EQ with a range of around -1dB .. +4dB @20kHz.
I have several for sale - these are sample pictures.
Signs of use vary, slighty worn off labelling is possible
Mechanical or electronic defects are excluded.
Each pair of transformers will be thoroughly retested and measured prior to shipping.
Please ask for an individual quote if you wish to purchase more pairs.
Two pairs can be shipped for the same price as one pair (5kg parcel).
Please contact me beforehand if you'd like to purchase more than 2 pairs for an individual quote.
Due to the pandemic there's currently a mark-up on all parcels to the US, hence the slightly higher postage.
I'm only charging actual costs.