RME DPS-2 Linear Power Supply

[Matias]

Review in German but use a translator if needed. In the end there are noise floor measurements of the ADC with and without the filters.

RME DPS-2 und RME LNI-2 DC – Stromquellen nach Reinheitsgebot - LowBeats

Auch bei digitalen Audio-Komponenten schlummert mögliches Klangtuning-Potenzial vor allem in den ana

www.lowbeats.de

 

[DEF]

Considering in their Manuals RME states that a linear power supply or similar won't grant audible performance gains, this really feels like some PR stunt.

 

[antcollinet]

Considering in their Manuals RME states that a linear power supply or similar won't grant audible performance gains, this really feels like some PR stunt.

I'd say it is giving the customers (or at least some of them) what they want. Some fervently believe that linear supplies are better for audio. RME can either offer them, or grant that business to the competetiion. That they offer them while telling no lies about the benefit is to their credit.

 

[unpluggged]

Considering in their Manuals RME states that a linear power supply or similar won't grant audible performance gains, this really feels like some PR stunt.

RME explains their purpose honestly. If some audiophools don't read documentation and expect something that had not been promised, it's not RME to blame here.

 

[MaxBuck]

The problem, as I see it, is that by offering this product RME gives implied credence to the notion that buying such nonsensical equipment offers some sonic benefit, even as the company explicitly says it doesn't.

It's problematic for me.

 

[Randyman...]

You can buy from a company that (irresponsibly) claim these kinds of things make a difference, or you can buy from RME who will be honest and tell you it won't make any difference At least we can be sure these units are sensibly engineered by RME. I don't see much wrong with this direction - being clear up-front was an important prerequisite, and these products follow RME's trek down high-end DAC Land. I did see one measurement where a flavor of the ADI DAC measured with less noise on the Linear PSU and Filter than running on batteries (just barely measurable, but surely not audible).

I say better to give the money to RME and their honest engineering - but I would never buy anything remotely like this. If my power is bad enough to need something like this, I'll fix the power issue at the source and "cure" all connected gear instead of band-aiding a dirty-power "fix" for one unit.

 

[KSTR]

There are some technical reasons why it made sense for RME to create this supply (see my post on page 1), plus there are economic ones as well. The stock SMPS supply wall-wart does work just as well in the most basic sense but it has some disadavantages and shortcomong:
- the DC cable is of lowest possible quality and doesn't survive mechanical stress and when it breaks it is almost impossible to replace as the unit cannot be opened for service
- it is butt ugly
- there is no way easily to mount it, let alone in a portable install
- there is a lot of mains leakage current which can create issues in a limited set of scenarios
In other words, it is not on par with the units that it power in many regards. That doesn't go well especially with their newly gained audiophile clientele and like everybody else they need to make money.

 

[Viennacalling]

Meanwhile - did someone compare the 2 modes himself?

 

[Roland68]

The problem, as I see it, is that by offering this product RME gives implied credence to the notion that buying such nonsensical equipment offers some sonic benefit, even as the company explicitly says it doesn't.

It's problematic for me.

But the one who is implying something here is you.
RME's statement for the power supply is very clear and it is a product for several pro audio devices.
In the professional sector in particular, plug-in power supplies are not very popular and the cost of lost work due to an overheated plug-in power supply that was lying somewhere underneath or slipped underneath quickly exceeds the purchase price. You also must not forget that the cost of the power supply is spread over at least 3-5 years of use, which is absolutely cheap compared to the cost of the employee in this area.

The price of the power supply is also completely justified when you take into account the quality of the materials, development effort, costs for measurements, EMC and long-term tests (also for CE) and relatively small quantities.

Personally, I always prefer high-quality external power supplies, for example because of quality, avoiding unnecessary interference in the electronics, cold device power connection, ideally stackability, etc.
As a former IT employee from high-availability IT, I appreciate such products from many years of experience.

Addendum:
You mustn't forget that there are really bad power grids with disruptions and voltage fluctuations. That's where a power supply like this is worth its weight in gold.
Especially in industrial areas and other areas, I've experienced several times that such disruptions were so massive that even high-quality devices, workstations and servers simply crashed and/or rebooted.

 

[Purité Audio]

Hopefully they don’t have plans for a ‘mains cable’.
Keith

 

[Roland68]

Hopefully they don’t have plans for a ‘mains cable’.
Keith

I wouldn't mind a high-quality power cable with high-quality plugs without PVC.
The ones I make myself cost me around €5.50 - €7.90 in materials (price range from 2-pin unshielded to 3-pin shielded, 1.0 - 1.2m). I know, expensive, but the quality and the lack of PVC is worth it to me.
It shouldn't be much more expensive industrially for corresponding quantities.

 

[Leeken]

Hopefully they don’t have plans for a ‘mains cable’.
Keith

I would if I was them,why bother with costly research when you can sell a kettle lead for a few grand,there’s far nastier shit being done in the world than selling ofc wire to the gullible.

 

[Purité Audio]

I would have preferred they re-designed/improved the current arrangement but still a good product/ trustworthy company only slightly diminished in my eyes.
Keith

 

[HaveMeterWillTravel]

There is no successful attempt at creating a measuring standard for measuring common-mode noise performance.

What should they show, show something that says their product is flawed while the others don't show that?

Common-mode noise is only really only relevant when two or more devices are connected.
Take for example a wireless streamer/dac/headphone amp. It could have horrendous common mode noise on the headphone output and it would never have any effect. Well, up until it generates enough leakage current to be a health hazard.

To clarify that a little.

There are no differences unless there is a source of external noise injection into the system.

The difference between balanced and unbalanced is in their ability to reject external noise, and nothing to do with their inherent (internal) performance. (ignoring typical voltage levels).

Well, in this case the common mode noise is not external to the interconnected system.

There are three main factors on why an XLR balanced differential will be better than a single-ended RCA which is referenced to chassis (which may or may not be tied to Earth Ground) reference connection:

The circuit impedance for the driven lines are significantly higher than the chassis connection, say 10 k to 100 kOhm versus an Ohm or two. With a single ended input, there will be a few orders of magnitude difference in the current amplitude traveling through wire connected the active lines and the chassis reference. The common mode noise has been effectively converted to differential noise. In contrast, with a balanced connection the circuit impedance for both lines are effectively the same so the current is similar. The induced voltage on either line is then far closer to each other. So the level of differential voltage is far lower. This benefit even applies to balanced/differential circuits which are two wire, thou I do not know how common that is with audio equipment.

Differential circuits tend to have better CMRR performance anyways.

Finally, the 3rd conductor or the outer shield if connected to chassis creates the same current amplitude difference as above. In this case, it reduces the current flow on both signal lines to virtually nil in comparison to the the 3rd con or shield. So any small differential effect is greatly reduced again.

Straight from RME here and here.

To make it easier I quote the two posts:

Ground issues, a ground loop, or no ground aka leakage current issues, or leakage with wrong grounding - all this could be cured by a linear power supply.

The last resort (if someone is unwilling or unable to connect it to a solid ground) is the use of a linear power supply. Their leakage current is basically free of harmonics and therefore typically inaudible.

(I bolded the interesting parts)

So we now have couple of explanations.

This is certainly not my experience having tested and used countless power supplies in applications far more demanding than audio. Take a very high gain charge sensitive preamplifier. One is effectively counting individual electrons (or holes) when the induced charge induced currents at the attoampere level. A high-end transimpdence amplifier may have a dynamic range of 240-260 dB.

Both linear and switchmode power supplies have leakage currents. Want to completely erradicate common mode noise? Power over fiberoptic baby!

 

[antcollinet]

Well, in this case the common mode noise is not external to the interconnected system.

Whereas i am talking about noise external to a particular device within the connected system, as you might have spotted if you'd tracked back the context of the conversation through the linked posts.

IE - for example a DAC to Amp analogue connection may have a perfect noise free output on the the RCA connections of the DAC, but due to ground currents carried in the shared ground connection/return path of the RCA interconnect will have differential noise added by the time it reaches the amp.

That noise is external to the DAC. I am pointing out that ground noise is not an inherent failure in DAC performance, but is a system issue.

You do seem to be intent - in many of your posts - on showing off your "superior" technical knowledge in a way that is perhaps unhelpful to the people (perhaps with less knowledge than you) that you are (hopefully) trying to inform. You also are often replying with this technical wizardry to individual posts, without taking into account the context of those posts within a larger conversation that has taken place prior to the post you are referencing, such as the one of mine here as I have highlighted. I've seen you do this also in the "power cables don't make a difference" thread. In fact all of your posts in that thread are completely ignoring the context of the whole thread.