The Linear Solution Reference 1 Linear Power Supply: Viable Alternative to a Paul Hynes SR7?

[Superdad]

6 hours ago, auricgoldfinger said:

I try to place the paper in the areas where I would imagine EMI emissions are greatest.  For the power supplies, start by placing some above the mains transformer.

 

Given that the 3M material absorbs emmisions mainly up in the GHz range, putting it around an AC mains transformer won’t do a darn thing.  Sorry. 

[str-1]

5 hours ago, Superdad said:

 

Given that the 3M material absorbs emmisions mainly up in the GHz range, putting it around an AC mains transformer won’t do a darn thing.  Sorry. 

In what range does an AC mains transformer generate emissions?  Are there consumer products suitable for placing inside audio devices, power supplies etc that would deal with that without impacting negatively on sound quality?

[auricgoldfinger]

7 hours ago, Superdad said:

 

Given that the 3M material absorbs emmisions mainly up in the GHz range, putting it around an AC mains transformer won’t do a darn thing.  Sorry. 

 

I was hoping someone knowledgeable would chime in.  🙂

 

Fortunately, the size and location of the EMI paper inside the case is still able to a make a difference by absorbing emissions from other parts.

[auricgoldfinger]

3 hours ago, str-1 said:

In what range does an AC mains transformer generate emissions?  Are there consumer products suitable for placing inside audio devices, power supplies etc that would deal with that without impacting negatively on sound quality? 

 

Maybe other EMI paper absorb different frequencies?  If @Superdad responds to your question, we can look into it.

[LTG2010]

36 minutes ago, auricgoldfinger said:

Fortunately, the size and location of the EMI paper inside the case is still able to a make a difference by absorbing emissions from other parts.

The transformer can give out lower frequency emmisions, but its construction might act like a big antenna absorbing higher frequencies and passing them down the chain, so in effect the paper shield might be protecting the transformers from outside interference.

If that is not feasable, then the paper could be absorbing (and also protecting) the rest of the components in the box due to proximity,

hence the noted difference / improvement in sound.

[auricgoldfinger]

Given the lack of response,  there must be some doubt regarding the statement on transformer emissions.

[auricgoldfinger]

You can find the actual data here on page 2:  http://multimedia.3m.com/mws/media/960849O/3mtm-emi-absorber-ab5000-series-tds.pdf

 

My observation is that this EMI absorber has been used successfully by others here on CA in various audio components, including at least one SR7.  So, the perceived improvement in SQ is either an example of mass delusion or yet another example of a real audio phenomenon whose mechanism is not well understood.

 

Also, IIRC, many Chord Blu Mk.II owners (as well as Rob Watts) found the most effective ferrite in reducing perceived glare operated in the 2.5GHz range.

[Johnseye]

7 hours ago, auricgoldfinger said:

You can find the actual data here on page 2:  http://multimedia.3m.com/mws/media/960849O/3mtm-emi-absorber-ab5000-series-tds.pdf

 

My observation is that this EMI absorber has been used successfully by others here on CA in various audio components, including at least one SR7.  So, the perceived improvement in SQ is either an example of mass delusion or yet another example of a real audio phenomenon whose mechanism is not well understood.

 

Also, IIRC, many Chord Blu Mk.II owners (as well as Rob Watts) found the most effective ferrite in reducing perceived glare operated in the 2.5GHz range.

 

I use the 3M EMI absorber in my SR7 with positive effect.

[auricgoldfinger]

51 minutes ago, Johnseye said:

 

I use the 3M EMI absorber in my SR7 with positive effect.

 

That makes 2 confirmed users in an SR7.

[Forehaven]

Where did you apply the 3M John?

[Johnseye]

40 minutes ago, Forehaven said:

Where did you apply the 3M John?

 

Top removable panel, both sides and a little on the front.  All inside the chassis.  I didn't do anything with the bottom.

[Superdad]

On 1/15/2019 at 4:52 AM, auricgoldfinger said:

Given the lack of response,  there must be some doubt regarding the statement on transformer emissions.

 

Uh, no doubt at all!  Transformers used in power supplies radiate at low multiples of the AC line frequency, plus a small amount of ringing at around 175KHz (typical, varies, depending upon diodes and if an RC snubber on secondary is or is not used).

 

So I'm afraid that GHz-absorbing 3M material is not going to do squat around a transformer.  

Maybe you gents are enjoying its effect on other components in the LPS, though again, nothing in a traditional LPS is going to be emitting anywhere near the GHz range.  The 3M stuff is slightly heavy and single-stick on one side, so maybe you are getting some mechanical damping benefits.  Kind of expensive for that application though.

 

If you want to block fields from power transformers, 3/8" aluminum is the ticket.  Have to be careful with steel and especially with mu-metal as strong fields will cause those materials to saturate if they are close.

[Solstice380]

6 hours ago, Superdad said:

If you want to block fields from power transformers, 3/8" aluminum is the ticket.

 

And it needs to a complete box, or cage.   Otherwise those little waves will come in everywhere else!  Holes, connectors that aren’t properly protected, etc.