MSB Premier DAC with Naim NAC 552 Preamp

[thijazi]

I just received my MSB Premier DAC with Digital Director, I am connecting this DAC to my Naim NAC 552 preamp which offers two choices for input, either RCA or 5-pin DIN connections. I have an XLR-to-RCA cable which I am currently using for this setup, but keen to hear if anyone has any views on using the XLR-to-DIN connection. Naim Audio seem to prefer that connection, and while I am aware this is not a balanced connection route, I would like to explore opinions on this topic. Keen to hear from anyone that has some experience with this.

Regards
Tareq

[Jonathan_Gullman]

Hello Tareq,

You should really use our XLR to RCA converter for best performance. A XLR adapter or adapter cable you are only using half of your Premier DAC. You will get better performance with our converter as it will allow you to use the entire DAC.

[thijazi]

Thank you for the reply, I was in discussion with the Chord Company about this, they are able to make a custom cable with the understanding that the signal will no longer be balanced and would terminate into a single-ended DIN connector,.

Can you please share some more about this? What would I lose with the custom cable rout? you mention using the entire DAC, how does the transformer enable this? Hope you can shed some more light on this intriguing topic, I can barely find anything online that explains it. When I probed AI about the same, this is what I got:

To connect your MSB Premier DAC with Digital Director to the Naim NAC 552 preamp using the DIN connector, you can use a custom cable that links the DAC’s balanced XLR analog outputs to a 5-pin DIN input on the NAC 552. This approach avoids using the single-ended RCA connection and takes advantage of the Naim’s preferred DIN input method, which many users claim provides sonic benefits in Naim systems.​

Cable Requirements

• The MSB Premier DAC outputs a standard balanced signal via 3-pin XLR connectors.

• The NAC 552 accepts audio inputs via single-ended RCA or 5-pin DIN (180°) sockets, but it is inherently single-ended—even via DIN.​

• You need a cable that converts a pair of XLR outputs (left and right channels) to a single 5-pin DIN plug, wired for left (pins 3, 1) and right (pins 5, 2) plus ground (pin 4 or shell).

Using a Chord Company Custom Cable

• For your setup, specify a cable with two male XLRs to one 5-pin DIN plug (180° standard version for Naim) and request that it is internally wired for stereo single-ended (unbalanced) operation, since the DIN input is not balanced.

• Chord Company can supply this cable to exact specifications; you should confirm with them that the cable will tie the XLR pin 2 (hot) to the appropriate DIN input, and handle pin 3 (cold) per the correct grounding scheme for your source and Naim’s requirements.

Notes and Recommendations

• The resulting connection will be single-ended, because the Naim DIN input is not balanced, but you will benefit from the high-quality XLR output stages of your MSB and the superior mechanical/electrical properties of DIN

Keen to squeeze the maximum out of the Premier so the path I chose is something I would like to research. Grateful to any more detail you could provide.

Regards,

Tareq

[Bones13]

As someone who did a bunch of (easy) DIY amp projects, and an owner of predominantly Balanced Gear, I have a perspective, and some explaining.

Balanced cables are more resistant to outside interference, and are commonly used on longer runs in the pro audio area. Still a solid choice in HiFi for the same reasons, less noise from the cable.

A single ended ‘device’ has a signal and a ground, going from input to output.

A balanced ‘device’ has a (+) signal, a (-) signal, and a ground. The ‘device’ has double the circuitry, one side to handle the positive, and the other to handle the negative.

Most single balanced to single ended converter cables simply either ground the (-) signal to ground, or “float” it by leaving it unconnected.

A better converter is either a transformer, or circuitry, that sums the signal from the balanced to create a better single ended output.

Not sure what’s in the MSB converter (that’s their proprietary info), but I’m sure it will work better with the MSB DACs than simply shorting out one of output signals.

So I am in the get a pair of XLR cables, a pair of RCA cables, and a pair of their XLR/ RCA adapters, camp. If you want the best.

I limited my pre-amp choices to those having at least a pair of balanced inputs, and a pair of balanced outputs (second output to headphone amp). In the past I made several single ended Firstwatt clones. I used a transformer converter to run those amps from my balanced pre-amp output.

I hope I helped your understanding of the choices you are facing.

[thijazi]

Thank you, this is the type of insight that is not easy to get, and is not obvious for the non-technically astute in the domain of electronics and audio engineering.

[Bones13]

Lol, I’m just a retired orthopedist. I understand V=IR well, but only understand the basics of electronics that I needed to learn to build a few projects.

I also had a room needing a 20 foot interconnect from pre to amp. XLR cables were the best for that.

As an aside, I also learned that the “dedicated” circuit I put in for my amps had a slightly different grounding that the regular room outlets, producing the hum I was trying to squash. (This installer error also caused my emergency generator to GCFI fault when used.)

[Jonathan_Gullman]

@Bones13 is correct. The best option would be a pair of XLR cables to our XLR-RCA converters. RCA output from the converters to the Naim. If you want to use a custom cable from RCA to the Naim DIN, you can do this as well. The XLR to RCA conversion is best done with the adapter. NEVER short the unused pin to ground. Using just pin 2 on the XLR, you are only using half of the DAC module, as the other half is generating the negative phase on pin 3.

With the proper conversion, you will hear a noticeable improvement.

I will also add that there is a single-ended option for the Premier DAC. It’s not as good as the external adapters, and 95% of those that have ordered it have had to send their DAC back to convert it to XLR as they seem to get a balanced amp/preamp within 1 year.

[thijazi]

Got it, thank you. I am checking about the availability of the XLR adapters with my reseller as we speak.

[thijazi]

I will go for the XLR-RCA converters from MSB, are there any recommended XLR-XLR cables that are recommended for this connection? (MSB Premier DAC XLR output to XLR-RCA converter)? Any experience here would be welcome.

[Dustin_Symanski]

If you are curious as to what the MSB balanced to single ended converters are and why they are optimal for MSB converters, here is an in depth explanation.

An XLR balanced cable has a shield ground and two signal pins. There is no ambiguity as to where currents should flow. The external EMI noise flows on the shield “ground” pin and the signal currents flow on the two signal pins. In a single ended RCA connection both the external EMI noise and signal current flow on the same conductor, the shield, while only the signal current flows on the “inner” conductor. This means that there is an ambiguity as to where currents will flow when a balanced output signal is connected to a single ended input. You could short the “negative phase” of the XLR to the “negative” shield of the single ended input, but this will disturb the transmitting electronics which will not appreciate being shorted to ground. At best this short will result in signal distortion, at worst this short will result in equipment destruction. Alternatively you could leave the “negative phase” of the XLR disconnected. This ignores the fact that the signal currents should be returned on the negative phase and will result in extremely poor system electrical performance. For example in an MSB DAC this will simultaneously throw away half the signal and unbalance the DAC modules resulting in worse conversion performance.

The easiest correct way to convert a balanced signal to single ended signal is to use a transformer. A transformer converts the input signal current to a changing magnetic field, then that magnetic field generates a signal on a secondary where the signal ground and shield ground may be combined without detrimental effects. This is a good general purpose solution, but due to physical limitations and parasitic effects is not perfect.

The MSB converter is an even higher performance, but similar, concept known as a transmission line BALUN (BALanced to UNbalanced). It consists of a high performance transformer core wound with a twisted pair of wires (a transmission line). The input of these twisted pairs are connected to the positive and negative signal pins of the XLR connector and the output of these twisted pairs are connected to the RCA connector and shield ground at the opposite end. This results is a DC coupled circuit that runs directly from the input XLR signal pins directly to the RCA output pin and shield ground. If there is an unbalanced electrical current from the signal pin being shorted to ground at the far end of the twisted pair, then that unbalanced signal current is turned into a magnetic field in the transformer core. This magnetic field resolves the unbalanced current by generating an opposing current on both of the wires in the twisted pair restoring signal balance from the point of view of the balanced source. The net effect is to allow both signal phases of the DAC to contribute to the single ended input signal seen by the amp or preamp (because they are directly connected) but resolves the fact that the negative signal pin is shorted to the shield ground on the single ended RCA side. The balanced source cannot “see” the short at the far end of the wires.

For a true DC signal, such as a constant 1 volt output, it is still true that the negative phase appears to be shorted to ground because of the finite ability of the transformer core to contain the ever increasing magnetic flux (called core saturation). However audio does not normally contain much DC so the transformer core can normally maintain the illusion that the negative balanced phase is not connected to shield ground. As long as the transmitting balanced circuitry does not care about occasional “DC shorts to ground” then this is the highest performance method of converting a Balanced XLR output to a Single Ended RCA input. None of our DACs cares about these occasional “DC shorts” on their outputs but other equipment probably will, so I cannot recommend our Balanced to RCA converters for use on any other equipment’s balanced outputs, unless that manufacturer OKs its use.

[thijazi]

Thank you for this!

I appreciate you taking the time to share this level of detail. The reason I was exploring this was in an effort to get the XLR output of the Premier DAC connected via a Naim recommended DIN input on the preamplifier side.

I have the system today connected via a straight pair of XLR-RCA cables, my logic was to follow the recommendation of Naim and get into the preamp via DIN since they see RCA as an inferior connection. But with all the electronics that have to be deployed (XLR-XLR cables, then the XLR-RCA converter, then RCA-DIN cable), I think the signal would probably end up being inferior to a straight XLR to RCA output.

If you are curious about the DIN versus RCA perspective that Naim have, here is a post that explains their point of view: Why Naim use DIN Connectors - Frequently Asked Questions - Naim Audio - Community

Thanks again for the explanation, fascinating!

[Bones13]

I have a local audiophile friend, who does use Naim equipment. There is a local brick and mortar that sells Naim, in addition to other gear.

He is planning to audition a pair of ATC active speakers that only accept XLR inputs. He says that he will be using a Naim DIN to XLR cable for this purpose. Not sure how they will work, but I hope to learn. He currently runs a Naim amplifier to ATC passive speakers. Should be an interesting weekend.

[thijazi]

Would be very keen to hear your impressions from this test.

[thijazi]

I ordered the XLR-to-RCA adapter/transformers from MSB, I hope that these will result in a better sounding system as I ditch the current XLR-to-RCA cable which I am using for the connection. Looking forward to testing this when the MSB adapters/transformers are installed in my system (are they called adapters or transformers?)