No hum with phono stages?!

… is possible!

Our friends Audio16 boys, take a deeper look and experiment with hum, that is always problematic with phono stages. 

This is good news for all audio enthusiasts dealing with sensitive phono systems. As I am experimenting with lots of turntables, arms, carts, step up transformers and phono stages one can imagine that there is quite some room for grounding issues when connecting all these units.

We were trained to make compromises, but in the end when dealing with excellent audio components there is no compromise at all – also regarding noise and hum. A very good electrical power supply with power conditioning also using its own fuse block is a perfect precondition for clean electric current. I have also installed  a special interior (!) protection unit against ligthning strokes. In the image the red block shows such a device.

The hum problem however  is dealing with proper or improper connections between the several units of a phono line and not in every case one is successful deleting all side effects, especially when running a complex system with many different phono lines.

Having discussed with my blog partner different measurements tackling hum I decided going for a BIG SOLUTION.

All units of my whole system were connected to a special copper bar this way bringing together all grounding lines to one spot leading to the grounding line of the electric installation. In a further step all single phono lines were examined and tested on its best way deleting hum. The findings supported that the grounding conections between a line are sometimes responsible for hum. Whenever they were taken away no hum could be heard at all.

Of course there are other possible causes inducing hum, electrical cables running in parallel with signal cables, turntable lamps very close to tonearm cables etc. A grounding installation as I am now using is an excellent and easy way dealing with hum issues. It is not very expensive but demands a careful design and implementation. In the end it is worth the work one puts in it.

the best way tackling grounding issues in an audio system get yourself a dedicated audio ground (=earth). Connect this ground to a thick cable with minimum diameter of 32mm².

Bring together almost all units to this one audio ground by using a copper bar as shown in the image (behind the turntables). Some dedicated lines need to be wired as a unit, you’ll have to find out, sometimes the power supply of a turntable etc.