Most laptop chargers are smp (switchmode) these days.
Try to get a linear charger for it, and your problems will be solved.
Cheers George
Try to get a linear charger for it, and your problems will be solved.
Cheers George
Filter tweak for digital backwash?
As my system improves, it’s easier to hear anomalies. The search is now on for a tweak to filter only digital backwash in my AC. The culprit is the regulated transformer power supply (120vac/19vdc converter) to the dedicated laptop for streaming.
The balanced power conditioner has separate outlets for analog and digital. The digital outlets already have built-in filtration for backwash. They work well. But, I need even more. When the laptop is running on its internal battery, the music is very smooth. Unfortunately, the battery life is short. When the laptop is running on the power supply, there’s a slight stridency. When the power supply is plugged in anywhere else, there is huge stridency. So, I’m looking for some gizmo to clean up the digital backwash in-between the conditioner digital outlet and the power cord to the regulated power supply.
I’m not looking for an overall line purifier. The balanced power conditioner does a pretty good job already. Any suggestions?
22 responses Add your response
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The least expensive unit I recommend, based on a lot of research this one: http://amzn.to/2h9R4Z4 Series mode power surge suppression also includes noise reduction that works down to about 3kHz, and that noise reduction is bi-directional. Most noise supression is too expensive, or doesn't work below 100kHz. These units are perfect for isolating a noise source. For $30 more this one adds their linear filtering technology, which works too, not sure you need it: http://amzn.to/2gMitgC Of course, more expensive Furman units include multiple different filter banks. I haven't tried them for bank to bank isolation though. Best, Erik |
OH! Almost forgot to mention, it has been shown that a lot of the noise from a laptop or PC isn't "noise" so much as a ground loop. Obviously, it looks like noise, but the fix is entirely different. For these you need a ground loop isolator. Here is one designed for medical instruments, so it's a lot cheaper than audio-grade but works every bit as well. :) http://amzn.to/2hgqSfU I would try this first, then try a power supply strip like the Furman. Best, Erik |
I thought it was pretty easy to deal with noise injection(?)It was 10 years ago, we had relatively low levels of noise to deal with. Today now we have designers making new things, like Class-D, Delta Sigma converters and SMP(S) (sorry Bob), that introduce even more complex noise structures and with much higher output of those noises, now these have to be dealt with as well. Without effecting the core body of the fundamental that we hope should not change "the music and it’s harmonic structure". Cheers George |
randy-11 Why aren't the engineers designing expensive audio gear dealing with these problems?I think working to reduce noise is a very tricky business, and I agree with georgelofi that there are more sources of complex noise than ever before. The problem is also compounded by the endless combinations of equipment that can be used with any given component. |
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When I see engineers post on various forums, they usually say it is trivial to design noise rejection into a circuit... Dunno myself. I'm sure there are more sources of complex noise than ever before but they are usually RF and often in the GHz range so should be even easier to filter out than other "historical" noise. OTOH, I did see a recent white paper from Intel on USB-C showing significant noise down to DC. |
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@steakster Noise is a very interesting phenomenon. You can think of it like the canvas of a painting. Just like a different canvas texture or tint could change the visual perception of a painting so too can noise with music or sound. Vinyl may be attractive because of the inherent high noise floor and listeners are able to use that background noise to advantage! We can hear at least 15db below a noise floor! Sometimes noise will help make some aspects of music more audible. |
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