a pair of Neumann U474A modules for sale: recapped and tested.
There were multiple revisions of these over the years, but the only schematic I could find that is floating around the internet for the U474A does not match these layout wise, but the pinout does.
The IC's in these ones are a (quad) TL074 and a (single) TL071
I tried to check the Kubarth website to see if there were any other doc.s but I can't find the Kubarth website anymore.
I have recapped these and tested them and they both work and sound good, although I cannot verify any technical specification, or if the thumbwheel dial markings are accurate, so "as-is"
50dB Gain is definitely attainable, so they are useful to the DIYer or experimenter etc etc.
I cannot include the 23 pin tuchel mating connectors, as I need to keep a pair in my shop.
for the pair, I am asking $300 USD plus $50 for shipping in CANADA and $65 to USA
I accept paypal in USD.
the external mating connector pinout for the tests I performed is below: (internally on these modules, pin 3 10 and 15 are linked together)
1 Input +
2 Input -
3 Input cable shield
10 Output cable shield
11 Output +
12 Output -
15 0V ground
16 +24VDC
20 connect pin 20 to pin 21 to bypass HPF
21 connect pin 20 to pin 21 to bypass HPF
23 Chassis (I connected pin 23 to pin 3 for my tests)
There were multiple revisions of these over the years, but the only schematic I could find that is floating around the internet for the U474A does not match these layout wise, but the pinout does.
The IC's in these ones are a (quad) TL074 and a (single) TL071
I tried to check the Kubarth website to see if there were any other doc.s but I can't find the Kubarth website anymore.
I have recapped these and tested them and they both work and sound good, although I cannot verify any technical specification, or if the thumbwheel dial markings are accurate, so "as-is"
50dB Gain is definitely attainable, so they are useful to the DIYer or experimenter etc etc.
I cannot include the 23 pin tuchel mating connectors, as I need to keep a pair in my shop.
for the pair, I am asking $300 USD plus $50 for shipping in CANADA and $65 to USA
I accept paypal in USD.
the external mating connector pinout for the tests I performed is below: (internally on these modules, pin 3 10 and 15 are linked together)
1 Input +
2 Input -
3 Input cable shield
10 Output cable shield
11 Output +
12 Output -
15 0V ground
16 +24VDC
20 connect pin 20 to pin 21 to bypass HPF
21 connect pin 20 to pin 21 to bypass HPF
23 Chassis (I connected pin 23 to pin 3 for my tests)