Mega5Est Bass+ Owners. DO NOT USE THE 4.4 ADAPTER

[AudioAmigoReviews]

Howdy Everybody,

Omar from Audio Amigo Reviews here.

I was preparing for my review of the HiSenior Mega5Est Bass+, and got to the point where I wanted to test the 4.4 adapter and see if it was safe. I had several comments on my video asking if the adapter was safe, and I even got a message from Hisenior themselves saying it was safe to used.

I assumed the adapter would be wired like this:

(Please excuse the crudity of this drawing, I didn’t have time to paint it or make it to scale.)

I believe that in this configuration, the Amp may be working extra, but there is no short danger to the chips.

So I pulled out my multimeter to test, and it isn’t wired like this… The adapter is in fact, wired like this:

(Please excuse the crudity of this drawing, I didn’t have time to paint it or make it to scale)

Both inverse signal rings are wired to the ground pins on BOTH IEM connectors.

I don’t think this is the ideal way to do this. I think this has the potential to damage some Amps/DAPs that don’t have the right protection circuitry.

I reached out to HiSenior this evening after measuring the adapter. Per the HiSenior team member I spoke with they are escalating this issue.

I have a video coming telling folks not to use the adapter since I would hate for some poor guy’s amp/DAP to fry.

While this wiring configuration might be safe for 99% of devices out there, I hate the thought of someone’s equipment dying while thinking this included adapter is safe.

Will update when the video is live.

[AudioAmigoReviews]

Video is live:

Mega5Est Bass+ 4.4 Adapter Testing- DO NOT USE- Amigo Investigates

[AudioAmigoReviews]

UPDATE:

HISenior Issued a statement and will replace your cable and adapter if requested.

I recommend you either throw the adapter away and use the 3.5mm cable normally.

Or email them to arrange for a replacement.

[Rikudou_Goku]

@AudioAmigoReviews

Do note that the GND on Pentaconn 4.4mm cables are NOT used AT ALL.

@AudioAmigoReviews

This is the correct way to wire it, which means you CAN go from BAL (male jack) into a BAL (female connector) out to a MALE 3.5mm SE connector.
But not the opposite.

[AudioAmigoReviews]

@Rikudou_Goku

Do note that the GND on Pentaconn 4.4mm cables are NOT used AT ALL.

This is my undertanding as well. I think there are some oddball headphones from Sony or Yamaha that may have used a grounded sleeve, but they’re oddities and use proprietary pinouts. But I also believe that most amps have the 4.4mm female socket wired in such a way that the sleeve pin connects to the amps ground plane. I could be wrong. This is the way DDHiFi and iFi’s adapters are wired, and I had originally assumed that HiSenior’s adapter was wired the same way.

All-New DJ30A (2021) 4.4mm Male to 3.5mm Female Adapter – ddHiFi

Headphone Adapter 3.5mm to 4.4mm by iFi audio - Convert your 3.5mm...

[Rikudou_Goku]

@AudioAmigoReviews

grounded sleeve

There are some accessories for the Sony walkmans iirc that actually uses the GND for well, grounding by connecting both the 4.4mm AND the 3.5mm port. Forgot the name though but something like that does exist.

@AudioAmigoReviews

This is the way DDHiFi and iFi’s adapters are wired, and I had originally assumed that HiSenior’s adapter was wired the same way.

https://www.ddhifi.com/en/product/dj30a/ https://ifi-audio.com/products/headphone-adapter-3-5mm-to-4-4mm/

Yeah…people shouldnt be using adapters that go from SE → BAL, PERIOD. Even if they manage to cut the risk of damaging either the amp or the transducer, there will be ZERO benefits to using the BAL output like this, besides the additional possible power output but in 99,99% of cases you arent ever gonna need more power than what an SE port can supply you with, let alone bal.

[AudioAmigoReviews]

@Rikudou_Goku

Yeah…people shouldnt be using adapters that go from SE → BAL, PERIOD. Even if they manage to cut the risk of damaging either the amp or the transducer, there will be ZERO benefits to using the BAL output like this, besides the additional possible power output but in 99,99% of cases you arent ever gonna need more power than what an SE port can supply you with, let alone bal.

100% Agree. I have no clue why HiSenior did it this way vs. Including a 4.4mm Manta Cable and a proper adapter.

Or you know… Swappable terminations… which are on IEMs that cost less than what the 3.5mm Manta Cable costs.

Based on my messages with their rep, I think this may have been due to their supplier insisting that the adapter was safe (Citing having sold 10,000 units with no problems) and the 4.4mm version of the Manta cable not being ready for launch.

They were desperate to get this out quickly to make the 11.11 sales period, and they took their cable partners word that this adapter was fine…

It’s a mess.

[Rikudou_Goku]

@AudioAmigoReviews

Citing having sold 10,000 units with no problems

Means having sold to 10 000 people that might or might not have had their amp/transducer damaged by it, congratz.

@AudioAmigoReviews

and they took their cable partners word that this adapter was fine…

Doesnt make them look good at all, this is pretty basic after all…

[AudioAmigoReviews]

Another statement from HiSenior.

Happier with this one, but still don’t know what they mean in point one…

[Rikudou_Goku]

Yeah im confused by what they are trying to say in point 1…