… is possible!
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 inproper 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.
After some discussions with Audio friends 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 exellent 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.
Friends coming to my place were really stunning that they heard the phono chains quiet dead. And there are still some Audio friends out there who will not believe that this is the real solution, at least in my system – so what!
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 mimimum 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.
4 thoughts on “No hum…”
I would be interested in more details of your grounding solution.
In what country do you live?
Your power cabling should have a ground by itself. Here in Germany the TN-C-S system (https://de.wikipedia.org/wiki/TN-System#TN-C-S-System) is very common and I have that also. So by that you have a ground wire already in your power outlets.
What I have in addition is a 10mm^2 wire from the oncrete-footing ground electrode (Fundamenterder in german) to my stereo system. It is curently not used as I don’t know if it is allowed to use it, I was also not sure what to do in that case with the ground wire in the supply cables. Keep it connected or rely exclusively on the separate audio ground.
By using only the audio ground at least the resistance between the neutral and the ground wire would be higher than in a TN-C-S system and I’m not sure about the effect in case of a defect/malfunction of one of the audio components.
It would be great if you could show how you have connected round (your adio ground and the power cable ground) in your system.
Earthing is not mandatory, beside safety issue. What is capital, is Earth to Ground strategy.
That strategy start by finding the Neutral and Phase best polarity, the one which results in the less earth leak. For this you may first remove all mains filter, there are useless in analogue audio. Mains filters will leak and worsen the situation, at worst they will increase noise in the audible range (yes just read what I described on Melaudia forum).
For this each apparatus should have a removable link connecting earth to ground in the device. All pro device use that, not kidding. You should study the earth to ground link in each device because designer will try to find way to avoid ground loop, with resistors, loop breaker or diodes all that is pure bullshit. Then when all devices are connected to mains and are equipped with an hard link (earth to ground), you must listen in which device the grounding link may stay, that will be the less noisy configuration. Or best measure with a psophometer, knowing that there should remain only one unique link usually either in power amp or in phono preamp.
Tuff job, but every engineer in pro audio do that, that’s the only way to Graal, the one to gain 20dB in noise.
Don’t understand? what that crap Pierre is telling? phone me or we can discuss at ETF,
I think that Eckart is using his grounding technique for the equipment in his ‘phono stage’ only so there shouldn’t be any problem with ground loops from the rest of his equipment i.e : preamps, power amps, tape decks, signal processors etc. I think I understand what you mean by testing each piece of gear to isolate which one might not like the earth ground. I once had an amplifier (Sumo Model Nine) that when connected to earth ground made terrible noise.
sorry for late reply due to vacation.
I do have a grounding in my power outlets too but as hum is a very complex matter it also depends on all preconditions and your on site configuration. You are describing a setup which I recommend checking with your local electrician, also regarding the used diameter of the cables. Just for being on the safe side. Anyway from the distance it sounds ok for me.
I am using a separate grounding cable for my listening room which ends at the grounding bar to which all units are connected. This grounding cable has no connection to my house. All power cables lead to dedicated power distributors (Mudra Akustik) without filters. I am using a huge Quantum purifier in front of it.
as you do have different reasons for hum (e.g. microphonics, lack of screening of power supplies, wrong setup in the unit itself -internal hum loops or magnetic decoupling -, magnetic impact on units or cables, ground loops) its is helpful to have a strategy for checking priorities or at least doing the whole programme!
your mission is well understood and I agree with you except of the filters. We not only have hum we also are confronted with HF-interferences which you don`t hear as clearly as hum. Nevertheless it has influence on the sound. We should also not underestimate the impact of longer grounding, signal- and power cables. Therefore I would suggest you are trying testing good filters and ferrite rings. Tell me about your results. Maybe going for proper appliances you will face another enlightenment 🙂
thanks for your support. In a complex system as I do have it you cannot end up with only looking at the phono installations.
That`s why some other people prefer running only one turntable, one tonearm, one cart and one record 🙂