Modifying WM1Z/A

[Whitigir]

The only logical explanations I have is that the Pure-Silver back plate must be very effective in absorbing “stray-Magnetic fields/currents” emitted by the Inductors being used by the Balanced output. It must be much more effective than other materials I have tried as listed (Copper, Aluminum).

So, the stray fields are not hitting and bouncing toward the other “inductors” and close by “components”, which in turns improve the performances ?



Shielded and Unshielded SMD Power Inductors First, the magnetic field generated by the shielded power inductor keeps the magnetic field within the inductor. It emits few magnetic fields outside the package and has a less negative effect on others parts that are in close proximity to it, therefore minimizing the coupling to other components or modules. In an unshielded inductor, some of the magnetic flux field is radiated outside. If a sensitive component or module is in close proximity to it, its normal functionality may be affected. Since the entire magnetic flux field is contained within the inductor, the power efficiency is higher. The inductor also contains less wire turns if it has equal inductance with the unshielded inductor. This results in the DCR being smaller for a shielded inductor, as compared to that of an unshielded one. If the DCR is the same for both the shielded and unshielded inductors, then this implies that the inductors utilize the same wire and winding turns. The shielded inductor should have a higher inductance value than the unshielded one. However, the inductance change versus the current curve will drop earlier because of saturation characteristics. This determines that the unshielded power inductor is easier to work with in a larger current.

if you read through this post carefully, you would know what I am trying to say here @Maxx134

keep in minds that I don’t even know if that would explain it. The performances improvements is observable, which you can replicate to observe. I am only trying to find the logical explanations since I observed the improvements

 

[Layman1]

if you read through this post carefully, you would know what I am trying to say here @Maxx134

keep in minds that I don’t even know if that would explain it. The performances improvements is observable, which you can replicate to observe. I am only trying to find the logical explanations since I observed the improvements

I suspect that the silver atoms are causing resonance with the flux capacitor :)

 

[Whitigir]

I suspect that the silver atoms are causing resonance with the flux capacitor :)

Roflmao! This never get old eh! Classic!

 

[Maxx134]

Even Aluminum or Copper plating, they are barely observable , the same as TDK sheets the whole plate

This is great that you did all this testing.
Many thanks for saving us the trouble!

As I mentioned, the only way to explain this phenomenon with pure silver back plate here was somehow the properties of pure silvers allow the coils to not be sending stray magnetic field that negatively effects the surrounding

This is very interesting!

Looks like you tried all the most popular metals for shielding.
There is another metal to maybe you can try and compare to your silver.

Unlike the others, It has a high "permeability".
It is steel.
Maybe worth a try?

 

[Maxx134]

I realized that when I reset my Sony to stock, that the NFC is on (enabled) by default...

I am now wondering if this NFC is affecting (interference) things...

 

[Maxx134]

The only logical explanations I have is that the Pure-Silver back plate must be very effective in absorbing “stray-Magnetic fields/currents” emitted by the Inductors being used by the Balanced output. It must be much more effective than other materials I have tried as listed (Copper, Aluminum

So, the stray fields...

I found some more info:
"...stray magnetic fields in the near field and in all planes, cancellation is only achieved in the far field..."

that info agrees with your findings of more noise with close copper taping.

So cancellation achieved with sheilding further away, which is observed with the silver plate.

Also I read that different metal's surface (skin-depth) characteristics, makes a difference:
"Permeability and frequency are both in the denominator of the skin-depth formula..."
So now there's a formula, and different values for each metal. (!)
That would also explain for the observance of the silver metal's different behavior..

 

[524419]

Anyone tried Copper or Aluminum foil on the back of the plastic cover?
How thick does the shielding need to be for it to be effective? The tape could be grounded very easily.

 

[Whitigir]

Anyone tried Copper or Aluminum foil on the back of the plastic cover?
How thick does the shielding need to be for it to be effective? The tape could be grounded very easily.

Am I counted ? If so, read my previous posts

 

[524419]

Am I counted ? If so, read my previous posts

I must have missed them

 

[Maxx134]

Anyone tried Copper or Aluminum foil on the back of the plastic cover?
How thick does the shielding need to be for it to be effective? The tape could be grounded very easily

Copper tape or aluminum tape on top of the plastic would be interesting as it is easy, but that thickness is very thin.
I assume only the surface effect takes place.

The plate thickness @Whitigir used for silver is 22guage (.6mm)

 

[Whitigir]

Copper tape or aluminum tape on top of the plastic would be interesting as it is easy, but that thickness is very thin.
I assume only the surface effect takes place.

The plate thickness @Whitigir used for silver is 22guage (.6mm)

They wouldn’t do anything either if you applied foils over the plastic plate, and have it grounded. It does reduce the Bluetooth range and receptions though....even if you leave out the cut out for antenna

 

[Sonywalkmanuser]

Just wondering if you are not going to use the nfc function on the wm1, would it be better to just shield off the nfc portion or disconnect the module internally(not sure if Sony OS will function fine with this disconnection).

Where I am coming from is to reduce another vector for whatever minuscule emi/rfi noise that comes from the nfc module.

 

[Whitigir]

Just wondering if you are not going to use the nfc function on the wm1, would it be better to just shield off the nfc portion or disconnect the module internally(not sure if Sony OS will function fine with this disconnection).

Where I am coming from is to reduce another vector for whatever minuscule emi/rfi noise that comes from the nfc module.

I already did that, and in fact, it would improve the sound a little (negligible).....just as much as a whole TK absorbent sheets To cover the entire balanced out section.

If you are not going to use NFC....it would be best to shield it off by replacing the rubber back with a metal plate as well

 

[Sonywalkmanuser]

That's great to know!

Because previously when I modded my desktop dac. As I am mostly using I2S or AES, I tried disconnecting the unused USB input module and found the dac's sound quality to improve slightly. I assume that more modules connected would increase electrical noise internally.

Maybe the other more extreme mod would be to remove away the internal wiring for the 3.5mm jack if you are 100% sure that your WM1 walkman is dedicated to 4.4mm audio gear only? This is coming from the rather tinfoil hat notion that the 3.5mm wiring/jack could be acting as antenna for emi/rfi noise.

 

[Maxx134]

Are you using some of the Audio Note Standard, I've not tried them before

Yes, for my mod, I am going to use all Audionote kasie and Audionote standard where bigger Kasie cannot fit.
I will explain why...

I realized that ALL the current caps (suggested & used in these mods), are leagues ahead of the stock caps performance.
Looking at the best caps that fit,
Rubycon & elna had the best specs.
Yet, once you pass over 2X better technical performance specs, will those numbers beyond that, be as important?
Now, how about over 20X??!

So I then thinking what's more important? Does it matter to have Ultimate specs, or the sound?

Then, after long hard look at many replacement cap choices (for sound this time), I realized that all existing caps, are all of older designs...

Caps contain chemicals. The sounds of these chemicals override the specs, pertaining to sound. This is why older Blackgate caps are regarded so well.

All other caps (with great specs) where said to "sound" bright or edgy or flat.
There hasn't been much innovation in this area. The top choice of "silmic2" & "Muse/KZ" are actually old. Panasonic updated with some like "FC", but no mention of sound.

Audionote is the newest electrolytics.
They do not post performance numbers in their specs, and instead focus to the (greater?) importance of sound.

So I am going with Audionote only, because they are the newest electrolytics out,
and I'm going to take their word on thier claims of being better "sounding" than elna, and as an replacement to blackgate..

mind 220uf works very well on the output. Not sure on upping the 220uf power cap to 470uf yet although I have the FG arriving to test

Did you test the power cap area yet?
I hope to be testing next week.
I'm going to try two paralleled caps, to offset/negate/elliminate any increase in ESR, from having it placed further away from the solder points, maybe at the top.
I plan to try two 220uf. Not any higher in value, as I feel thats a safe precaution.