Spdif out to XLR

[Axel]

Morning all!
I’m trying to get a balanced signal from my E440 Pro to feed my headphone amp. I’ve seen Spdif to XLR converters online but are they any good? Do I have any other options?
Any advice would be very welcome,
 Thank you in advance.

Edit: I’m running the inputs from the D via RCA to my Auralic which is driving my HD 800s in balanced mode and I’m hearing a faint 50Hz hum. Not sure if it’s the RCAs picking up mains interference or a ground loop.

[ada]

If I am not missing anything there is no way to get a balanced output from Devialet Experts. The converters won't really provide you a balanced output. Your best shot will be using the digital SPDIF out of Expert but in that case your headphone amp needs to have a digital in (and a DAC).

[Axel]

If I am not missing anything there is no way to get a balanced output from Devialet Experts. The converters won't really provide you a balanced output. Your best shot will be using the digital SPDIF out of Expert but in that case your headphone amp needs to have a digital in (and a DAC).

Thanks, yes I realise there’s no way of getting a proper balanced output from the Dev. I don’t want to change my headphone amp to achieve this, but I’d like to get rid of the 50Hz hum, which is only bearly noticeable as doesn’t interfere with listening at all, but you know how picky some of us "audiophiles" can be! Haha.
I’m going to check the routing of the RCA cables from D to HA to make sure they are away from potential sources of interference.

[thumb5]

Might be worth trying some phono cables constructed as twisted pairs with shielding, perhaps?

On second thoughts, your ground loop theory might be more likely.  It seems surprising that you'd get EMI pick-up on what's a fairly high-level signal driven by a low-ish impedance pre-amp output.

[Delija]

Keep in mind that preout from Devialet Expert (Pro) doesn't use the main signal path which is used for amplified speaker output. Preout is of (somewhat) lower quality, with different DAC - meant to be used primarily for subwoofers.

[devianet]

As noted previously in this forum, I have been highly impressed with the pre-out when used to drive headphones - directly - from the Expert.

If the secondary DAC used for the pre-out is of lower quality, than I haven't been able to hear that lower quality in the headphones.

[ada]

Where is the proof that Expert has a dedicated DAC for preouts? As far as I know the DAC is on the main board of Experts, independent from ADH and CI etc.

[devianet]

I think that it was in a block diagram I remember seeing at some point.

But to me the following chain of thinking indicates it really strongly:

Theory: All (frequency) filtering in the Expert is done in the digital domain, i.e. as DSP upstream of any DAC.

Fact: It's possible for the main outputs to have different filtering from the pre-outs. (Subwoofer, SAM).

Consequence: The main outputs must be downstream of a different DAC to the pre-outs.

Or happy to be proven wrong.

[Axel]

Might be worth trying some phono cables constructed as twisted pairs with shielding, perhaps?

On second thoughts, your ground loop theory might be more likely.  It seems surprising that you'd get EMI pick-up on what's a fairly high-level signal driven by a low-ish impedance pre-amp output.

Thanks @thumb5
I think I’ll have a look at the cable routing before I do anything else.

[hardcore]

Edit: I’m running the inputs from the D via RCA to my Auralic which is driving my HD 800s in balanced mode and I’m hearing a faint 50Hz hum. Not sure if it’s the RCAs picking up mains interference or a ground loop.

First check if there is anything else connected to the Auralic and disconnect that. You could test if it's a ground loop by ground lifting the Auralic using a cheater plug (if it's safe to do so) and see if the hum goes away. If it does, then you confirmed it's a ground loop.

If so, you can try a ground lifter like this ifi GND Defender on the Auralic:
https://www.silentpower.tech/products/gnd-defender

DO NOT ground lift the Devialets though, as the manual specifically says that you should not.

Another option is to try an isolation transformer. These are some of the best.
CI-2RR | Jensen Transformers
I've used their subwoofer version in the past.

Another option if the Auralic has a balanced input with a transformer, is to make a custom RCA -> XLR cable, but do not connect the ground pin on the XLR side.