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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?


steakster
steakster OP
720 posts
 
Thx all for the excellent suggestions. I’ll update when I implement a ’fix’.

In the meantime, I’ve been swapping wire on a different linear ps (120vac/12vdc) that goes to my Empirical Audio Off-Ramp. From Ebay’s Tajacob’s - Jake’s Old Western Electric stuff, I’ve been sampling a variety of vintage WE 20 gauge wire - solid core tinned w/paper insulation, solid core un-tinned w/plastic insulation, solid core tinned with cloth insulation, etc. They each affect the sound considerably differently - sometimes, significantly. Crazy-making. Maybe taking up golf would be a good alternative.
randy-11
1,913 posts
 
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.


steakster OP
720 posts
 
Update: @shadorne Your suggestion worked - of putting a filter in the DC leg between the laptop and its power supply. I installed an ICT PCM-12 ADL, which is used for automotive electrical. Now, both the AC & DC legs are filtered. The laptop power supply is still plugged into the AC digital outlet of my balanced power conditioner. I like this filter so much, I’m going to get another one for the 12vdc power supply to my digital re-clocker. ICT has two versions: a PCM-12 ADL for 1-100vdc. and a SPM-12ADL for 0-17vdc.

My system has been fairly resolving for a while - now it's more so. It’s interesting to observe that digital noise offers the perception of ‘body’ to the music. When the noise is stripped away, the music can sound a bit ‘lean’. Then comes the challenge of adding weight back to it again - sans noise.


shadorne's avatar
shadorne
7,333 posts
 
@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. 
steakster OP
720 posts
 
Update: Added a 2nd ICT PCM-12ADL to my system. This time to the 12vdc linear power supply for the digital re-clocker. Wow! Clean, clear, beautiful music! If you have an Astron or similar linear power supply, I highly recommend this unit. A very inexpensive, yet very effective tweak a la Ebay.
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