The peaks around 10Hz, yes.
What is this RHS panel?
It is a line filter. NEC TOKIN LF-205A
Can a line filter make someone happy?
When I had installed it I did some listening tests (filter in/out). I couldn’t say that it degraded the sound, so I left it connected.
The diagram looks good
http://www.nec-tokin.com/english/guide/noize/no-lfsn-e.pdf
I had placed a lot of attention into the PSU of that preamplifier.
Can any one of you who has a Naim with the NA322 MM RIAA module measure the overload figures? I was surprised to read that the specified overload margin is 42db from 2Hz to 40kHz. They quote a sensitivity of 2mV.
George
Exactly.
All the audio system AC power cables going from point A to point B should be bundled together. For too long cables, a good compromise is to fold the excess cable into layers much like taffy candy.
Tell that to the person in our cycle group who died from a heart attack last week while cycling..., crossed 4 lanes during and got hit by an SUV to close the deal ..
The right approach, IMO. If one wishes to investigate whether particular techniques or tweaks in combination are "effective" or not then the number of permutations to investigate rapidly spiral out of control - my approach is to throw enough "tricks" at the system until the quality is at least "sufficient", and either leave it at that, or try for something better again. Trying to assess whether a particular, standard tweak can then be removed with minimal effect is just asking for headaches ...It is a line filter. NEC TOKIN LF-205A
Can a line filter make someone happy?
When I had installed it I did some listening tests (filter in/out). I couldn’t say that it degraded the sound, so I left it connected.
The diagram looks good
http://www.nec-tokin.com/english/guide/noize/no-lfsn-e.pdf
I had placed a lot of attention into the PSU of that preamplifier.
!As an example, I did the twisted and folded thing, mentioned above, on the power cord to the Yamaha keyboard right at the beginning - how much impact did that have? I haven't the energy or interest to precisely "measure" that - if the beast now performs adequately I'll leave well enough alone ...
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T
It is a line filter. NEC TOKIN LF-205A
Can a line filter make someone happy?
When I had installed it I did some listening tests (filter in/out). I couldn’t say that it degraded the sound, so I left it connected.
The diagram looks good
http://www.nec-tokin.com/english/guide/noize/no-lfsn-e.pdf
George
Overall the filter looks good with both normal mode and common mode chokes. The caps to ground are the concern. They drive noise into ground along with 1/2 of the line voltage. If you can keep that ground, usually the case, well isolated from your audio ground you will have fewer issues to deal with. I see these problems between instruments on my test bench. They are low level but really limit the noise floor.
Not really, I've blind tested optical versus coax with a positive result.
The right approach, IMO. If one wishes to investigate whether particular techniques or tweaks in combination are "effective" or not then the number of permutations to investigate rapidly spiral out of control - my approach is to throw enough "tricks" at the system until the quality is at least "sufficient", and either leave it at that, or try for something better again. Trying to assess whether a particular, standard tweak can then be removed with minimal effect is just asking for headaches ...
As an example, I did the twisted and folded thing, mentioned above, on the power cord to the Yamaha keyboard right at the beginning - how much impact did that have? I haven't the energy or interest to precisely "measure" that - if the beast now performs adequately I'll leave well enough alone ...
How about audiotioning with and without, just to try to make out any differences?
Sometimes, the differences can be literally startling, all the more so when you consider that you are externally filtering a $20k+ device, and the difference is obvious and positive with the filter.
In very, very few instances, the external filter can degrade the sound, again with revered audio gear well into kilo whatever, $ or €.
If you have never tried, how will you ever know?
Also, the caps to the ground could shift the ground potential on occasion, when a large spike hits the filter, and I've seen with my own eyes spikes of just over 900 V in a nominally 220 V line. True, they last a few microseconds at a time, but even so, things will happen, and I hate the very idea.
Another oddity is that regarding line noise, there is prescious little difference between the developed and undeveloped countries. The undeveloped countries have poor national grid systems, typically with insufficent and outdated local transformers, but less devices on line, while the developed countries have better to much better national grids, but more devices on line. In the end, it tends to even out.
I base this on some measurements made in 2001-2003 in Serbia, France, Germany, Hong Kong, Algeria and Egypt. These were available for me. I know it's not a valid statistical number of samples, but it's enough to draw some very general conclusions.
What's it like for you you can perhaps see for yourself. Connect an oscilloscope to your power outlet, set bandwidth to 1 MHz and amplitude to 1 kV. Then take a sedative and watch.
DVV is this years Darwin Award candidate.
It is completely irrelevant what comes out of your wall outlet; what counts is how clean the power supplied to your circuitry is. It is not beyond the capabilities of modern engineering to get to nanovolt ripple levels, if so desired. Which is way overkill for audio.
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