I used Noiseblocker PR-1 and a 3pin to 2 pin adaptor cable to connect to the header inside the PSU
http://www.blacknoise.com/site/de/produkte/noiseblocker-it-luefter/nb-blacksilent-pro-series/60x60x25mm.php
https://www.amazon.de/Wentronic-Adapterkabel-3-polig-Stecker-Kupplung/dp/B003D6O53Q/
The fan was selected based on the spec of the original fan in the GERMAN PSU, a 04020VA-12P-BA.
http://www.nmbtc.com/fans/part-numbers/DC-Axial-40mm/1608VL-04W-B60-B00/6147
With different PSU versions you need to check for the spec of the original fan installed, in order to reach the same flow.
I did disconnect the internal fan to place the 3-2 adaptor on the original pin header inside the PSU and threaded the cable out through the opening of the PSU.
Before doing the mod I also did measurements of the fan coming on with the sound recorder. Attached a photo of the measurement. A cold machine starts the fan up at about 21 mins after power-up and then every 8 mins for 640seconds. When it's already warm it will begin the first cycle 4 minutes later.
After installation of the mod I recomfirmed that the new fan is working. It comes on at the same time as the original, but runs longer. When it comes on it seems to "stutter" a bit, butI think it just reacts to smaller currents beofre actually coming on. It does come on reliably and has no issues with long evenings of intense playing. No measurement there though, as it'S impossible to record.
Duty Cycles (resized).jpg