Conversion of a Chord DAVE to DC power using two Uptone Audio JS-2s

[DAVE JS2]

Doing this will void your warranty on the DAVE, goes against the advice of Rob Watts (designer) and Chord, your experience could differ from mine for a host of reasons, and you are of course entirely responsible for any damage you do to your equipment (or anything else) in the process. I also realise it’s not exactly a solution that’s available to all.

 

Notwithstanding all that, I wanted to share this in case it was of interest / use to anyone, as I have found the results to be excellent, and well beyond my expectations. I got what I consider to be a big step change up, not a small evolution.

What did I do?

Replaced the onboard SMPS within my Chord DAVE using two JS-2s (each factory modded to offer 15V from one output). There’s a link to a full description at the end of this post.

 

The actual conversion was well planned in advance, but was a pretty quick & easy thing to do on the day; I am not the most experienced at this type of thing (its the first time I have ever opened up a bit of HiFi kit), and its entirely reversible if you’re even minimally careful.

Why did I do it?

I’ve been hearing for myself the extent of the role of the quality of AC and DC power in sound quality, and in the process finding the DAVE to be very sensitive to power noise & RFI.

 

I’d read on another forum a post about having good results from doing the DC conversion. It made a lot of sense to me and felt it was worth a shot.

How does the DC-converted DAVE sound?

I thought it was already very good, but I’ve noted the following significant qualitative improvements:

 

Performances are more toe-tappingly engaging, completely effortless to listen to, of greater clarity but also with greater smoothness, a very sophisticated sound, the performers and instruments properly feel like they are in the room with me, and I am compelled to listen to my whole library again.

 

I perceive it as a significant step up rather than a small increment. I’m hearing new things in, and new aspects of, every track. I feel it liberates the rest of the DAVE, the SMPS was really holding it back. Its real music.

 

To attempt to use hifi-reviewer vocabulary to describe what aspects of the sound changed:

Much faster transients, highly detailed, better bass depth, weight and focus, instrument separation, even wider soundstage. It removes a sheen of harshness, sibilance is gone. All this is in the context of real musical coherence, rather than ‘hifi’.

 

This improvement was independently verified by my good friend and fellow hifi ‘victim’ who came over to help me with the mod, and my eye-rollingly sceptical wife who says the overall effect of the new detail & in-the-room ‘presence’ is “creepy” - which I’ve taken as an endorsement 😉

What were my expectations?

Given my experiences with the ferrite cores on the BNCs and AC power cables to the Chord kit (see below), I felt / knew the DAVE was sensitive to electrical noise.

 

So I was hoping for improvements to the classic symptoms of electrical noise e.g. reduced harshness & sibilance.

 

What I wasn’t prepared for was the transient speed, bass depth & control and soundstage / presence improvements; ironically I felt these were already good (they’d been improved a lot by a mains spur & thick direct-wired power leads - again, see below).

What’s the rest of the system?

To give some context:

 

Speakers and listening position are in equilateral alignment and care has been taken with siting in the room.

The room has been acoustically treated (by me not a professional) to give a pretty flat frequency response. [Incidentally; in the past I used DIRAC room correction, and I’ve found doing it ‘au naturelle’ eventually gave much better soundstage / presence.]

 

I use Roon with ethernet data going through a couple of Uptone etherRegens, the second one in the listening room and linked via SFP fiber to a Sonore opticalRendu, a single JS-2 powering both.

 

The Sonore USB out feeds a Chord Blu Mk II for WTA upsampling, the output of which goes via Chord’s dual BNC connection to the DAVE [several ferrite cores were needed here to reduce noise from the FPGA in the Blu Mk II corrupting the analog section of the DAVE - its a known issue, ferrites are Rob Watts recommended work-around].

 

An Uptone UltraCap 1.2 feeds 5V to the USB ports of both the Blu Mk II (I use a dual headed iFi Gemini cable into the Blu Mk II) and the DAVE [This is because i) their USB interfaces use USB 5V to power an internal USB clock; and ii) I have found by experimenting that sound quality is directly related to the ‘quality’ of power on those USB interfaces - even on the unused USB port on the DAVE].

 

Balanced output from the DAVE (used in pre-amp mode) goes to a Krell FPB700cx which drives a bi-wired pair of B&W 800 D3s.

 

There is a dedicated 40A mains spur to power the kit in the room, no fuses in the way to the main bits of equipment (there are RCDs and MCB of course). There is a combination of iFi active noise cancellation and ferrite cores on the AC power leads (which I made up myself from 6mm2 cables). [I put the ferrite cores on the DAVE and Blu Mk II power leads because I had some left over left over from the BNC ‘fix’, I got curious and tried it, and harshness / sibilance was improved.]

How did I do the conversion?

I’ve described it in this linked Google doc (with photos!) to try and keep this post to a vaguely manageable length.

 

Special thanks go to Alex at Uptone for his patience when answering my questions and taking the time from his busy schedule to verify the JS-2s would do what I was asking of them before he allowed me to buy them :)

 

Thanks for reading, hope it was of some interest!

 

[DAVE JS2]

@MarkusBarkusYes, dreamy indeed! I'm like 'the cat that got the cream' now when I listen.

 

I'm now turning my thoughts to the Blu Mk II, and I'm curious to know if you use one (or a Hugo MScalar) with your DAVE, and if so whether you've (or anyone else reading this) tried similarly improving the power supply and with what result?

 

I had a quick peek inside the Blu Mk II and I think its the same SMPS as in DAVE, but there looks to be more PCB in close proximity around it.

[DAVE JS2]

Thanks @MarkusBarkus,

 

I am considering swapping out the Blu Mk II for the TT format MScaler as one option, so just wanting to ask you the obvious question and confirm... did the Farad3 improve the sound over the OEM SMPS?!

 

All the best!

[DAVE JS2]

That's so interesting @ecwl, sounds like good thinking to go into the device optically. I also spoke to Rob, a couple of years ago now, and know his opinion is that good quality 24 bit recordings are more impactful on quality than high sample rate. I have to admit I used to seek out High Res files, but since the advent of streaming and MScaler I'm really happy with 44.1k. Although I do beg to differ with him about those SMPS he uses, given my recent experiences...

 

I am also considering that same swap of Blu Mk II for MScaler that you did, I have literally used the CD part once. It was the only game in town when I got it, but the fact the MScaler is already DC capable is pretty attractive to me...

 

Where in Canda are you? My wife is Canadian, from Nova Scotia. We go back there two or three times a year (in normal times) but I haven't found too many fellow audiophiles. Sadly I tend to not have much to contribute to conversations about lobster fishing, hunting and trucks... ;)

 

Your room convolution experiences sound fascinating. For me Dirac, I thought at the time, was ironically too successful - by taking the room totally out of the equation I thought the sense of soundstage and 'musicians in the room' was lacking in the final analysis. I started using it as an 'insurance policy' just before I got my 800 D3's as I have a smallish listening room and wanted to be sure I would be able to control the energy they are capable of putting into the room, but have been able to sort things so its not needed, and is better now. My long term endgame goal does involve filtering though, I want to use Roon DSP to implement a digital crossover(s) with high end DAC & good power amp per driver. For which the DACs need to be able to synchronise clocks.

 

Anyway, sounds like I have some catching up to do on Head-Fi - thanks, and all the best!

[DAVE JS2]

12 hours ago, ecwl said:

I think the consensus is that you’re better off asking @mitchco to help you create a convolution filter in Roon.

Thanks (again) @ecwl - I appreciate the pointer re: @mitchco, I will try and look out the thread and investigate.

 

If you ever feel able to investigate swapping out the SMPS in the DAVE, I can only recommend it based on my experience - it, too, is shockingly better :)

 

All the best.

 

[DAVE JS2]

17 hours ago, MarkusBarkus said:

n my opinion, in my system, it did improve the sound.

Awesome, thanks for the info @MarkusBarkus

[DAVE JS2]

3 hours ago, asdf1000 said:

 

Btw: I don't write all this just to argue.

:)))

 

Thanks for your posts - I'm sure you are right re: measurements etc.

 

I don't really have a grasp of the theory(s) but based on my experience I'm convinced that taking the SMPS out of the DAVE is one of the best upgrades I've ever done, whatever the reason for the improvement.

 

It's the hobby that keeps on giving. Barely gives one any spare time to listen to music... ;)

[DAVE JS2]

17 hours ago, JohnSwenson said:

There are two main aspects of power supply that I find important for digital audio:

1) leakage current

2) output impedance over frequency

Thanks @JohnSwenson for your comments, and for your ongoing work that has brought so much enjoyment to myself and so many others; can't wait to find out what's next!

[DAVE JS2]

15 hours ago, skatbelt said:

 

I agree with you. With the development of DAVE, Rob Watts mission was to design a state of the art DAC within the technological possibilities (at the moment). I therefore see the choice of a SMPS as part of the overall the design decisions. If a LPS would have fitted better within this philosophy and contributed positively to the objectives, then he would undoubtedly have chosen that route. 

 

There are very good SMPS's and very bad SMPS's just as there are good and bad LPS's. The problem in high end audio is that SMPS almost seems to be a curse word because of the image that is created by the large group of very cheap and noisy ones.

 

I also have reservations about the objectivity of the OP's assessment. Unless he directly A/B-ed his modified DAVE with a 'standard DAVE' ceteris paribus I cannot take 'shockingly better' very serious.

 

On the other hand, I have experienced that DAVE is sensitive to the quality of the power provided. For example, a dedicated power line, an isolation transformer with balanced power and a better power cable all brought audible improvements in my system.

Thanks for your comments @skatbelt

 

One would hope Rob / Chord took the approach you describe, I'm simply reporting that I heard very meaningful improvements after the switch (as have others).

 

You raise a fair point about objectivity, and of course as I don't have two DAVE's I can't easily do repeated A/Bs. The conversion took maybe 20 minutes in all, so there is that gap too. However, set against those potential issues are the facts that I was using tracks that are VERY well known to me, same volume levels, the conversion was done after about an hour or so of acclimatisation of listening with my friend (so his and my wife's opinions too, not just mine), and I was actually not expecting that much to change (if anything). That's really the reason I posted about it; it was such a dramatic change when there are many reasons to expect it to be subtle, at best. I remain delighted with it.

 

On another topic, I'm really interested in your experiences with your isolation transformer, having had a dedicated mains spur put in over the summer.  I'll try and read up more about it myself, but presumably the reason you do this is to further reduce mains noise? Do you have any before & after measurements? Also a question about the transformer size, am I direct in thinking that do you need to match up the transformer spec with the needs of the electronics 'behind' it, particularly the power amp?

 

Thanks in advance for any information.

[DAVE JS2]

3 hours ago, ecwl said:

I’d probably look to see if there are any bass peaks to tune out using parametric EQ in Roon.

Thanks for the thought @ecwl; thats actually exactly what I did after I got my room as good as I could the 'old fashioned' way, and had only minor uplifts corresponding to the room L, W, & H.

 

I found that I couldn't really tell any difference with the parametric EQ in or out, so decided to leave it off.

 

I'm pretty certain now that I'm going to swap Blu Mk II for Hugo MScaler and use a JS-2 for power, I think there were RFI improvements to it compared to Blu Mk II.

[DAVE JS2]

2 hours ago, skatbelt said:

 

I won't start a psychological discussion... :)

 

There is a whole thread in this sponsored forum about isolation transformers, infused by - who else? - John Swenson:

 

 

 

When implemented properly it will reduce high frequency common mode noise on the AC line. All details can be found in the thread. It is quite a read so in short you'll need an isolation transformer that has enough headroom to power the needed wattage behind it and one that has extreme low so called interwinding capacitance. You need to power all components behind the transformer from one power strip and make this part of the system a closed group in electrical terms. So, no copper connections with powered components that aren't part of the group to prevent from leakage currents.

 

I have mine wired for balanced power. It is a moderate 1KVA model but this plenty enough to power a dCS Network Bridge, DAVE and a Lyngdorf TDAI-3400. The uptream network components are isolated via an etherREGEN and a separately powered subwoofer is isolated via a Jensen transformer.

 

I perceived implementing this as a full component upgrade with added tranquility, ease and realness and at the same time more details in sound reproduction. The difference between balanced/symmetrical vs. asymmetrical was quite shocking to stay in your terms... :)

 

 

 

Thanks so much for taking the time to explain all that @skatbelt, I really appreciate it.

 

I'll definitely dig into that thread in the coming weeks for the details.

 

I heard changes like the ones you describe when I switched to a separate power line, but I'd imagine there is still noise on there. I'm still working out how to measure the noise to see what the extent of any further gains might be...

[DAVE JS2]

3 minutes ago, ecwl said:

Sounds like you just don’t have any major problematic bass peaks. Usually if you have peaks more than 5dB, an exact parametric EQ to tune it out would make a pretty obvious difference. Correcting troughs usually don’t work.

 

And yes, I suspect in your system, JS-2 + HMS probably would sound better than Blu Mk II. Even without the JS-2, the USB input of the Blu Mk II is not galvanically isolated whereas the HMS one is. So that alone would probably gives a bit of improvement. Although maybe not because you already have lots of ferrites on your dual BNC cables. I don’t use ferrites. I think Rob Watts thinks adding ferrites between HMS and DAVE actually makes things worse? Whereas ferrites between Blu2 and DAVE are better.

 

Ah thanks for the info on HMS - sounds like he learned some lessons from Blu Mk II then! I did not know that about the USB.

 

At least ferrites on vs. off the BNC cables is a pretty easy A/B to do!

[DAVE JS2]

Thanks @ecwl and @MarkusBarkus, very useful.

 

As I understand it the USB interface on the Blu Mk II itself was a last minute addition based on dealer feedback on the prototypes, so perhaps there wasn't time for a thorough job.

 

I believe the 'RFI' on those BNCs is derived from the clock frequency of the FPGA in the Blu and HMS. It sounds like I should be prepared to keep the ferrite cores on my BNCs regardless (but I will experiment of course!). I wonder if there is any form of optical replacement of BNC cables that someone out there in internet land has tried? That would probably end up being a minefield of noise from the transceivers, power supply angst etc... in itself, but probably worth a Google at some point, though.

 

edit: hah: https://audiobacon.net/2020/02/22/audiowise-opto-dx-the-rf-noise-killer/

[DAVE JS2]

Oh my goodness @ecwl @skatbelt @asdf1000

 

This epic Head-Fi review / article / journey is incredibly comprehensive and touches on pretty much all the topics we have all talked about / around in this thread.

 

Recommended reading, when you've got a fair amount of spare time, and its worth getting through to the end. Also worth reading his linked piece about his DIY 'Ferrite Cable of Shame' as background.

[DAVE JS2]

Thanks @skatbelt, looks I've got more reading ahead to catch up with everyone!!

 

This is all fascinating, I'm delighted to be learning so many new things.

[DAVE JS2]

15 hours ago, kennyb123 said:

I have a ton of respect for the folks at Chord.  Rob is a genius when it comes to converting bits into live music.  He really gets sampling theory.  He also understands human hearing and particularly our sensitivity to timing.  His understanding places him amongst a very small group of experts.

 

Having said all that, I’d rather have someone other than Rob design the power supply for his digital products.  Guys like John Swenson, Paul Hynes, Sean Jacobs and Mattijs Vries may be to power supplies what Rob is to D-to-A conversion.  Both my Chord devices (TT2 and HMS) were massively improved with Farad power supplies.  Thus I’m not at all surprised the DAVE gained hugely from an improved power supply.

 

The other essential component when using an HMS is the OPTO-DX.  I can’t speak highly enough about this product.  I know Chord doesn’t think anything like this is needed, but I’ve benefited from tuning them out on this the same way I have tuned them out on power supplies and music servers.  I love Chord to death, but I think the breadth and depth of understanding needed to get everything to the point of being exceptional is a bit too much to expect from one or two guys.  We have to look to multiple experts and try our best to pull it all together in a way that works best for us.  

Thanks for your comments @kennyb123, I totally agree with you - 'We have to look to multiple experts and try our best to pull it all together in a way that works best for us."

 

Every time I listen to music I'm glad I switched out that SMPS from the DAVE for JS-2s, and a HMS, JS-2 for power and OPTO DX with appropriate power are now firmly in my sights, plus want to investigate an isolation transformer (I'd be all in, except as I understand it I'd need a 5.6kW one for my power amp alone :/ ).

 

Although new to the forum I've had my learning fast-tracked by everyone on this thread, plus I found @ray-dude's posts about his experiences to be very helpful. Overall I now realise I i) am not alone, ii) am not crazy and iii) at least vaguely going along the right track! 

 

Cheersll

[DAVE JS2]

16 hours ago, skatbelt said:

I suspect that the delta is determined by how well this supply is able to suppress mains noise and instabilities relative to the built-in supply

 

Agree, on noise, isolation and regulation, but I also think the ability to deliver significant current very quickly is key.

 

[DAVE JS2]

1 hour ago, asdf1000 said:

It would be cruel to just ask him to measure and deny him a chance to listen 😢 

 

Hang on...what about the cruelty of depriving ME of listening to my upgraded DAVE?!

 

It is just one that Chord has bought in (see photo), and I'd imagine @JohnSwenson has more pressing matters to attend to. But I'd be happy to send it if it would be of use to him.

[DAVE JS2]

2 minutes ago, skatbelt said:

Hmmm, there goes my assumption of purposely built or at least custom built to spec for Chord.

 

This Head-fi post is Rob Watts on the medical SMPS, whats important in a PSU for his DACs and the further conditioning measures he uses in the DAVE, post PSU.

 

" Would using a better SMPS give better SQ? Maybe, but the evidence suggests no. "

 

I read that piece before deciding to give the JS-2s a go, and you know my conclusion: 😳. ;)

[DAVE JS2]

16 minutes ago, Nenon said:

 

I have noticed that the older DAVE DACs use the above off-the-shelf product. The newer manufactured units I have seen, 2020 in particular, had this one - EOS Power LFWLT40-3002. It's a $15 power supply on a $10K+ DAC. No wonder we all like this upgrade :). 

 

They can talk as much as they want about voicing, but...

 

and...

 

In other words, the voicing around the $15 SMPS was not really something I liked in my system. 

 

Yeah...

 

Rob's Head-fi post indicates that not a great deal of thought went into the SMPS (no A/B testing, @skatbelt😱 ) despite all the downstream work he describes.

 

To paraphrase @kennyb123, best to combine the world-class elements that each of these leading individuals bring to the table and 'tune out' other elements based on our own experiences and preferences.

 

Though it would have been nice to have an external DC input, as with HMS, to allow for experimentation without voiding the warranty... 🧐

[DAVE JS2]

On 1/15/2021 at 1:45 AM, ray-dude said:

 

Quick update: after a couple months of running the DC4 7/24, it was fully burned in so I was able to get to get my deep dive done over the holidays. (note to self: never sign up for a review of a component with giant Mundorf caps unless you have time/patience for a couple months of burn in)

TL;DR - It's awesome with DAVE!

Look for the multi-part (sorry, I couldn't help myself ;) review to be posted pretty soon.

 @ray-dude Fantastic, thanks for letting me / us know - I'm looking forward to setting aside the time to read it ;)

 

Don't forget to let everyone know that other LPS' are available... 

 

Quick update from my end; I have just got round to earthing all the unused inputs on my DAVE (couple of BNC's, XLR and USB) and Blu Mk II and was pleased with the improvement / effort ratio - further reduces the RF noise, a 'calmer' listen. Should have done it long ago. You guys have probably done it already, but I mention it 'just in case'.

 

Over the next few days / week I'll be DC converting the Blu Mk II, will post her about how I get on. Wish me luck!

[DAVE JS2]

25 minutes ago, asdf1000 said:

I'm not question the improvement you hear but this is generally not recommended practise (earthing all inputs).

 

I don't think this would be recommended by John S or Rob Watts.

Interesting thanks - do you know what the issue might be? It seemed like a logical thing to do to me.

[DAVE JS2]

Just now, asdf1000 said:

 

System grounding is a really complex topic.

 

@JohnSwenson has written a lot about it on various threads.

 

This is a good place to start

 

https://www.avw.com.au/images/techpapers/Rane_note_110.pdf

 

@asdf1000 Thank you very much, I will read that.

 

For clarity; I earthed the grounds, not the signal lines (apologies for my sloppy language).

[DAVE JS2]

4 minutes ago, asdf1000 said:

 

All good. I don't know if that's any better though 😀

 

The main thing is it didn't get worse for you, which is the biggest danger with improper system grounding - when you start to hear audible buzz/hum.

 

And I guess it is possible that (by luck) you actually have objectively improved things too. 

 

It's such a complicated thing that the only way to get good advice on system grounding is to sketch up a full system diagram LOL. Showing how everything is connection.

 

That's a lot of work but it's really the only way an expert here (not me) could give good advice.

 

Other than that, reading the Rane article is a great place to start.

@asdf1000 I'm coming at it from trying to tame the RF sensitivity of the DAVE and Blu Mk II - I definitely feel like I'm on the front foot of the battle at the moment. I'll take my lucky shot!

I feel it did help me, but I will be sure to be mindful in future.

 

Thanks again for taking the time to reply and your advice, its much appreciated.