[elira]

Man, I'm realllly tempted to take my WA11 to my engineer friend, get it open up and see how the internal is. For a product that's been around for more than a year, it's interesting that we never saw the internal of this, at least none that I can find on Google search.

I might just do that if Woo isn't interested in addressing this issue... lol

I think the problem with that is that you need to remove the alcantara patch, and you will probably ruin it.

 

[jeffri]

I think the problem with that is that you need to remove the alcantara patch, and you will probably ruin it.

That's a good point, which is why if I'm doing it, I'm getting a professional help.

 

[HiFiGuy528]

A use case here is that a Digital-Audio-Player (DAP) with a balanced headphone output (4.4mm or 2.5mm) can be used as a source. The answer is it depends if
1) the DAP's balanced output has a ground (Lotoo PAWGT 4.4mm output does)
2) if there is an unbalanced output. In the case of #1, the answer is yes. However, most DAP's balanced output does not carry a ground wire because it is designed to be used with headphones. There are 4 wires, namely L+, L-, R+, R-. That leads to case #2 that you will need a connection cable to "borrow" a ground from the unbalanced 3.5mm headphone output which is typically found in most DAP.

Again, most DAPs with 4.4mm or 2.5mm balanced output are designed to be used with headphones. There are 4 wires, namely L+, L-, R+, R-. There is no ground wire because headphones does not need it.

For example, to connect a Sony WM-1A to the WA11 via balanced output will need a cable that would look like the one in the picture below. The thin wire is a ground wire that you plug it into the 3.5mm unbalanced headphone output to "borrow" the ground.




Another example is the Astell&Kern PEF21 Balanced cable for their DAPs for use with home audio components. Note the dual jacks, 2.5mm and 3.5mm are wired to the dual 3-pin XLR.




Now, back to the 4.4mm balanced input on the WA11. It is a Pentacconn 5-pole connector. The wiring scheme is
L+, L-, R+, R-, GROUND, from tip to the bottom pin.

The argument here is that the source does not need a ground. That is incorrect. All analog interconnection cables MUST have a ground or you will hear a noise in the sound.

The reason that we use a 4.4mm balanced Pentaconn analog input on WA11 topaz is for use with balanced audio components such as home DACs, CD players, Phono preamplifiers, etc with balanced XLR outputs. This allows the user to add a high-performance headphone amplifier to those sources where (typically) does not feature a headphone output.

If you are using balanced home audio source, a connection cable would look like:

Audio sources (DAC, CD player, Phono pre, etc.) with dual 3-pin XLR output:
- Left channel: PIN 1 - ground/shield - PIN 2 - positive/hot (+) - PIN 3 - negative/cold (-)
- Right channel: PIN 1 - ground/shield - PIN 2 - positive/hot (+) - PIN 3 - negative/cold (-)

WA11 topaz input: 4.4mm balanced plug (5-pole) to dual 3-pin XLR balanced connection
- Left channel (+) PIN 2 / Left channel (-) PIN 3
- Right channel (+) PIN 2 / Right channel (-) PIN 3
- Ground to PIN 1 both Left and Right channel

If we didn't use Ground on WA11's 4.4mm balanced input, the connections with balanced home audio components outlined above would not function correctly and would cause noise in the signal.

Hope this helps clarify our choice to use all 5 poles on WA11 topaz 4.4mm Pentaconn balanced input.

 

[jeffri]

Hey Mike @HiFiGuy528

Glad to see you here again after all of these. Would you be able to address the concern that we have with 4-pole connection to WA11 line in? Will that damage WA11 or not? If so, would you be able to explain the technical aspect of why?

Cheers

 

[HiFiGuy528]

Hey Mike @HiFiGuy528

Glad to see you here again after all of these. Would you be able to address the concern that we have with 4-pole connection to WA11 line in? Will that damage WA11 or not? If so, would you be able to explain the technical aspect of why?

Cheers

updated my post above. pls. take a look.

 

[jeffri]

updated my post above. pls. take a look.

Thanks for the response. I understand that it is not ideal setup and will add noise to the output if ground isn't connected.

The concern I still had if, it is connected without ground, will it cause any damage to the WA11?

 

[HiFiGuy528]

Thanks for the response. I understand that it is not ideal setup and will add noise to the output if ground isn't connected.

The concern I still had if, it is connected without ground, will it cause any damage to the WA11?

it will not but we don't recommend it. It would just be noisy or have very low volume.

On a side note, power OFF the amplifier before changing cables or headphones is good practice for ANY audio device. The act of "hot swapping" is bad especially if working with home audio components.

 

[jeffri]

it will not but we don't recommend it. It would just be noisy or have very low volume.

On a side note, power OFF the amplifier before changing cables or headphones is good practice for ANY audio device. The act of "hot swapping" is bad especially if working with home audio components.

Noted, thanks.

With so many recent DAP releasing with 4.4mm output nowadays, it will become a quite common use case where we would try connecting 4.4mm to line input of WA11 to feed to larger headphones. We wouldn't know if the ground is connected in these DAP, so glad to know that it is safe to connect at least, regardless if the result is satisfactory or not.

 

[jeffri]

On a side note, power OFF the amplifier before changing cables or headphones is good practice for ANY audio device. The act of "hot swapping" is bad especially if working with home audio components.

Oh, also, I found this interesting. Should I really power off the amplifier before connecting headphones? I thought the best practice is to power on amplifier first, then connect headphones. The "pop" when powering on the amplifier isn't good for the headphones driver and is a risk that would damage the driver, isn't it? The pop is honestly quite loud in WA11, especially to easier headphones like my TH900.

 

[JohnZS]

Noted, thanks.

With so many recent DAP releasing with 4.4mm output nowadays, it will become a quite common use case where we would try connecting 4.4mm to line input of WA11 to feed to larger headphones. We wouldn't know if the ground is connected in these DAP, so glad to know that it is safe to connect at least, regardless if the result is satisfactory or not.

Indeed interesting to see that WA11 will not be damaged if the ground is missing.

So I presume 2.5 to 4.4 without ground is also OK(not optimal) to use and will not take the risk of damaging WA11?
If my presumption is true, then how the cable from Moon Audio was to blame and by using it I committed 'improper use' thus I was reliable for the damage?

Will Woo Audio note the correct configurations(legible and with complete content, not just 'Pentaconn') when they are selling those?

Why my WA11 got damaged after I start using 2.5 to 4.4 (4-poles)? Prior to that, more than a year of usage with USB has been totally fine.

 

[HiFiGuy528]

Noted, thanks.

With so many recent DAP releasing with 4.4mm output nowadays, it will become a quite common use case where we would try connecting 4.4mm to line input of WA11 to feed to larger headphones. We wouldn't know if the ground is connected in these DAP, so glad to know that it is safe to connect at least, regardless if the result is satisfactory or not.

Again, most DAPs with 4.4mm or 2.5mm (A&K noted "only support 4-pole") balanced output are designed to be used with headphones, not to be sent to an amplifier's LINE IN (not specific to our amps).

When using a DAP with WA11 topaz, we recommend the USB input for the best sound and compatibility.

The 4.4mm balanced LINE IN on WA11 or any amplifier's balanced LINE IN should be reserved for balanced sources with the appropriate cables as outlined in my post #648. https://www.head-fi.org/threads/woo-audio-wa11-review-preview-head-fi-tv.879132/post-15772086

 

[JohnZS]

To help sum:

• 4pole to 5pole will not damage the WA11
• 4pole w/o LO function is a 'NO-GO'
• WA11(a *portable* device) is recommended to use USB with DAP. (ESS SABRE Reference DAC only *as recommended*)
• No description on the WA11 product page never mention more details other than 'Pentaconn balanced [5-pole]'

With '[5-pole]' added recently after I requested adding more details to Mike.

I think the above is a fair summary, let me know if anything you think I misunderstand any part above.

Now other facts:

• My WA11: via USB 3/2019-7/2020=OK,

via LO(4 poles) within a few days=Borken

• The broken WA11 was used with SE100 w/ LO function(as all A&K DAPs has)
• The SE100 involved in this has been used for car-audio system for hundreds of hours via LO to the AMP w/o any issue.

I don't think there is(educate me if you know) any portable device that's *5-pole(truly grounded unlike Sony) w/ 4.4 LO*

It seems to me there are a few points needed more explanation.

Edit: *as recommended* added with 'only' moved before it to make it as fair as possible.

 

[jeffri]

Again, most DAPs with 4.4mm or 2.5mm (A&K noted "only support 4-pole") balanced output are designed to be used with headphones, not to be sent to an amplifier's LINE IN (not specific to our amps).

When using a DAP with WA11 topaz, we recommend the USB input for the best sound and compatibility.

The 4.4mm balanced LINE IN on WA11 or any amplifier's balanced LINE IN should be reserved for balanced sources with the appropriate cables as outlined in my post #648. https://www.head-fi.org/threads/woo-audio-wa11-review-preview-head-fi-tv.879132/post-15772086

I understand the recommendation part. When using DAP, of course we would like to try LO function DAP has (which sometime is just maxed out volume on HO). So aside of known DAP with grounded balanced out (i.e LPGT), this is sometime an unknown factor until we try it and see it works. As long as this use case don't damage WA11, I think we are good and we can try ourselves which chain is better from the DAP (USB or LO).

 

[jeffri]

• WA11(a *portable* device) is only recommended to use USB with DAP. (ESS SABRE Reference DAC only)

To be fair, I think this is not "only", it is recommended to use USB for best compatibility with DAP.

When using LO, it is recommended if the DAP has balanced out ground or using special cable with separate ground.

Either way, this is "recommendation", at least the confirmation from Mike is this won't damage WA11 if line in is connected without ground.

As for your case, I guess, let's wait for their final finding for now. I hope they will outline what is broken and what is fixed when all is said and done.

 

[JohnZS]

RSA SR71B and ALO RXMKIII

To be fair, I think this is not "only", it is recommended to use USB for best compatibility with DAP.

When using LO, it is recommended if the DAP has balanced out ground or using special cable with separate ground.

Either way, this is "recommendation", at least the confirmation from Mike is this won't damage WA11 if line in is connected without ground.

As for your case, I guess, let's wait for their final finding for now. I hope they will outline what is broken and what is fixed when all is said and done.

That's fair, sorry for the confusion.
I will change that.