Help: HD600 + Balanced cable + RHA DacAmp = Mono?

[nicolajhl]

Hi guys,

I own a pair of HD600 that I am very happy with, I then decided it was time to treat the headphones with some new upgraded cable, and since my RHA DacAmp L1 have a balanced 4-pin mini xlr output, I went with a Mini-XLR cable that came with some adapters for other types of plugs. The cable feels great and I am very happy with the look and sound.

Now, the problem I am having is that when I use the Mini XLR output from the RHA DacAmp I seem to be getting both left and right channel in both ears, like Mono. Then if I use an adapter to connect the Mini XLR cable to the regular mini-jack output of the DacAmp it all sounds right again with left and right channel seperation.

I have a hard time figuring out why this happens, but I suspect either the cable and output have different wiring or the RHA DacAmp isnt actually providing a balanced output signal.

Some information on the products.

• RHA DacAmp manual
• Hart Audio Cables HC-5: Dual Sennheiser Balanced Headphone Cable
  • You will find a diagram of the wiring of the cable in the link
• The headphones I am using, Sennheiser HD600

Please let me know if you need some more info, hope you can help enlighten me!

 

[buke9]

My guess is the amp uses a different pin out for the mini 4 pin but I don’t know because it is the only amp I’ve seen with a min xlr for a output.

 

[nicolajhl]

My guess is the amp uses a different pin out for the mini 4 pin but I don’t know because it is the only amp I’ve seen with a min xlr for a output.

Someone on Reddit told me they may be wired specifically for their IEMs 'RHA CL1' which may not be the same as a normal balanced xlr output. I dunno, I've wrote RHA and hope they will shed some light. Seems weird to me that they would use a 4-pin xlr differently than every other company, but there is always surprises to be had in the world of HiFi lol.

 

[buke9]

Someone on Reddit told me they may be wired specifically for their IEMs 'RHA CL1' which may not be the same as a normal balanced xlr output. I dunno, I've wrote RHA and hope they will shed some light. Seems weird to me that they would use a 4-pin xlr differently than every other company, but there is always surprises to be had in the world of HiFi lol.

Well most don’t use a 4 pin mini xlr as a output connector.

 

[nicolajhl]

Well most don’t use a 4 pin mini xlr as a output connector.

True that, it's a very unusual plug, but I thought it was quite smart implementation of balanced XLR in a very small device. It's actually a very nice plug to work with, feels solid and satisfying to use.
Anyway thanks for the reply, I might just look for a new head amp with regular XLR balanced output. Since spending another 30 usd for a converter to the RHA DacAmp seems a bit much and I'll also then be using two adapters with different design which will look and feel not great.

 

[litalienadg]

Hi,

I have a RHA dacamp L1 too and I'm also trying to make a custom balanced cable to use the balanced output.
My first try was wiring it like the cable from Hart Audio which is wired like all 4 pin balanced xlr should be ^^

However I didn't get a dual mono in result... I had L+R on one side and nothing on the other.

Therefore, I think pin 1 and 2 are positive, pins 3 and 4 are the negatives.

Moreover, when looking up some images of the inside of the the DAC we can see written R-, L-, R+, L+ (and I don't want to open mine to see the soldering from the inside)
So, I will try today to wire it : (1)L+, (2)R+, (3)L-, (4)R-

Pinout of female connector viewed from behind = pinout when looking at RHA :

I will keep you updated with my experiments, if you have any info on the xlr pinout I'd be pleased to learn about it

 

[litalienadg]

So, here are the results of my tests, pins are in order 1,2,3,4

Test : L+,L-,R+,R- :
I had mono on one side and nothing on the other

Test : L+, R+, L-, R- :
Nothing on either side

Test : L+, R-, R+, L- :
Only left side working, no crosstalk

Conclusion :
The right balanced output does not work on my device, and that is a new problem to fix.... I bought it second hand quite some time ago and have never tested it before

FOR THE PINOUT :
It seems like RHA had fun inverting the two negatives !
The pin layout should be the following

(1) : L+
(2) : R-
(3) : R+
(4) : L-

Here again is the pinout of female connector viewed from behind = pinout when looking at RHA :

Edit :
If I get both outputs to work, I will check the phase of the signal to be sure they didn't swap that too