1980's Australian designed, manufactured
Ex Broadcast Industry audio input module
Great for re-purposing where a high quality, balanced audio input module may be required OR simply remove the very nice audio transformer and use alone.
Balanced Audio Input Module
Single Channel
Dates from the late 1980's period
Module uses a SINGLE rail supply of 24V DC
Input is balanced
Output is balanced
Active device is NE5534
PCB mounted trimpot allows for gain adjustment (feedback loop)
Module measures: 78mm length x 46mm wide x 36mm height
Weight (mainly the transformer) is 75g
CONDITION:
Excellent
NO damage to any component
"Tails" have been left which enable easy identification of the connections
Black - Red - Green = audio balanced
Orange - Black = 24V DC input
TECHNICAL NOTES:
THE TRANSFORMER
Designed and manufactured by Harbuch Electronics located here in Sydney. This company designs and manufacturers very high quality transformer based products and many of their components can be found in broadcast equipment of this era.
I used to supply Siemens ferrite products to Harbuch in the 1980's but I don't know what they are up to these days, they appear to have moved from Hornsby to Artarmon. The website now is pretty "flakey" - it looks like a "work in progress" you can try having a look yourself HERE
On their website it does state:
"Individual data sheets are available for each transformer type listed in this guide. These sheets have a photo and mechanical drawing, response, THD and phase plot, specification panels and an oscilloscope photo of the response to a 2kHz square wave at a level just below maxium rated output or input."
So according to that info, a phone call may glean more technical information that could be required
The circular can style casing is Mu metal.
Can size: 31mm diameter x 31mm height
The base has a screw thread with nut to secure it to the board and should be connected to ground
The leads (5) all exit the transformer can from the underneath, these are colour coded stranded wire leads NOT PCB pins
Specifications are difficult to come by these days but I can assure anyone interested of the following:
Frequency response is to AT LEAST 15KHz - this is normal for broadcast audio equipment
Turns ratio 1:5 (200 Ohm to 5K) REFERENCE
If access to this link is difficult (as happened for me) it really seems to be a bit flakey at the moment, further evidenced by there being NO photographs at all
THE AMPLIFIER
Based on the common NE5534 high performance Op amp and it appears to be configured as a voltage follower/buffer amplifier.
Trimpot adjusts the amount of output signal being fed back to the inverting input (feedback loop)
Single rail supply, 24V @ pins 4 & 7
TESTING
Prior to removal from the original audio equipment, this module has been tested and is working fine
