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!

 

[MarkusBarkus]

Oh, it's of interest! I had a second espresso for "heightened awareness" before I opened mine up. 
 

Getting that little SMPS out of its little CNC-ed nest was very satisfying.

And it sounds dreamy, right? What noise floor?
 

Good on you for sorting all that out, with Alex @DAVE JS2. 

[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.

[MarkusBarkus]

@DAVE JS2 I do not have a Blu Mk II, but I do have the MScaler. I run it from a Farad3 and I like it very much. Very clean, detailed sound, if you like that flavor.

I only ran the OEM SMPS for about as long as it took for the Farad3 to cross the Atlantic. 

 

I have been considering other PS options, including a rail from a JS2, but admittedly, this sounds pretty good as it is, and the only driver is curiosity. 
 

I use the Mundorf wire/recipe on a PFBuffalo switch and am considering it for the DAVE umbilical. That will be a bit pricey, so we'll see. Good luck!

[ecwl]

5 hours ago, DAVE JS2 said:

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 have gone kind of the diametric opposite direction as you did in order to improve the DAVE sound.

First, I traded in my Blu Mk II to an M-Scaler because I don’t actually use the CD transport as I’m 100% computer audio. Then like you, I have some UpTone products that do improve the sound a lot but having read @JohnSwenson’s comments about ground loop leakage current noise being a major component of noise affecting performance and that solution is proper grounding and not using SMPS and using linear power supplies instead, I just wondered instead of constantly trying to upgrade the power supply, what if I just remove the ground noise issue all together. So my UltraRendu is actually connected to a USB-Toslink converter (unfortunately max 96kHz) and the M-Scaler is fed Toslink. So my M-Scaler, DAVE and Etude are still powered by the original SMPS and are the only devices connected to each other. In fact, I discussed this with the Chord DAC designer Rob Watts and that was what he recommended since I don’t even have high-res music beyond 96kHz. (Actually he said I can try a USB to 192kHz Toslink converter). But on Head-Fi forum, there are definitely some people who have replaced their M-Scaler SMPS with linear power supplies instead and report a sonic improvement.

 

I also noticed your comment about Dirac. I recently bought Acourate and spent over a month learning how to optimize the convolution filter. My experience seems to suggest that it is very difficult for an automated program to find the optimal convolution filter so even if you have programmed to your preferred frequency 

response, it is very easy to end up with a phase correction that loses PRaT. I suspect that’s why you weren’t happy with Dirac. 

[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!

[MarkusBarkus]

2 hours ago, DAVE JS2 said:

...did the Farad3 improve the sound over the OEM SMPS?!

@DAVE JS2 in my opinion, in my system, it did improve the sound.

 

FYI: I have the Level 2 cable (not the silver) and the inlet and fuse upgrade. As I recall I did HiFi Tuning fuse, not the Orange. Maybe should have sprung for the orange, but...

[ecwl]

7 hours ago, DAVE JS2 said:

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... Although I do beg to differ with him about those SMPS he uses, given my recent experiences...

 

Where in Canda are you? My wife is Canadian, from Nova Scotia.

 

Your room convolution experiences sound fascinating.

I think Rob Watts (and maybe even John Franks) have this really odd philosophy about SMPS. They fully acknowledge that if you have a grounded computer audio device connected via USB to their SMPS Chord components, you’re probably going to get a little bit of ground loop leakage current noise that’ll affect the performance of their products. But Rob Watts definitely thinks that’s not his problem. It’s the problem of the computer audio device. Because when he tests his DACs, he just runs them with his laptop running on battery. And truth be told, I cannot tell the difference in sound when I connect my iPad via USB to M-Scaler/DAVE vs Toslink. But ideally, I would much prefer to be able to connect my UltraRendu via USB into M-Scaler. And despite using LPS1 and grounding my router, NAS, cable modem, etc. I keep hearing progressive improvements but it’s still slightly different than playing straight from the iPad or Toslink. So I finally caved and just went Toslink. But it’s definitely possible that replacing Blu2/M-Scaler/DAVE with high-end linear power supply would improve the sound. I just never bothered trying it. Felt like too much effort. With all that said, I think Chord has definitely lost some sales because people plug all sorts of things into their USB and the “incompatibility”? with the SMPS limits the performance. I think I’ve even heard this problem at Chord dealers.

 

I live in Winnipeg now but grew up in Toronto as a teenager. Originally grew up in Hong Kong. I actually stayed in Nova Scotia for a month. Very nice people. But yeah, I know what you mean... Different parts of Canada definitely has slightly different culture even if people generally are very nice.

 

I was talking about my convolution experience in another thread. I think the consensus is that you’re better off asking @mitchco to help you create a convolution filter in Roon. I strongly suspect you’ll be shocked by the improvement, even with the B&W 800 D3. I don’t know what @mitchco charges but it’ll probably be more worth it than changing to M-Scaler + a linear power supply.  It may even convince you to abandon plans to do separate digital XO for each driver. It took me a month to fully understand how to optimize the convolution filter in Acourate. It was a good learning experience but I think it’s time I could have spent doing something else.

[asdf1000]

15 hours ago, ecwl said:

but having read @JohnSwenson’s comments about ground loop leakage current noise being a major component of noise affecting performance and that solution is proper grounding and not using SMPS and using linear power supplies instead

 

Maybe I misunderstood here but I don't think @JohnSwenson ever generalised that the solution for proper system grounding necessarily means using linear PSUs instead of SMPSs.

 

In fact I'm pretty sure I've read both John S and Rob Watts mention there are SMPSs better than linear PSUs and vice versa..

 

The solution for proper system grounding isn't always straight forward because it will vary between each unique total system.

 

[ecwl]

6 hours ago, asdf1000 said:

 

Maybe I misunderstood here but I don't think @JohnSwenson ever generalised that the solution for proper system grounding necessarily means using linear PSUs instead of SMPSs.

 

In fact I'm pretty sure I've read both John S and Rob Watts mention there are SMPSs better than linear PSUs and vice versa..

 

The solution for proper system grounding isn't always straight forward because it will vary between each unique total system.

 

You’re absolutely right. I can’t remember John Swenson mentioning SMPS can be better than LPS but he definitely never thought they are inferior, just different. Rob Watts definitely thinks SMPS when done properly is superior to LPS. 
 

I think the real challenge is that for someone like me with limited understanding of electronics and grounding, I can see it’s so much easier to say let me switch the SMPS to LPS so that I don’t have to worry about the high impedance leakage current noise. Rather than to analyze where the noise and grounding issues are. And I did try but in the end, since the Chord DAC architecture is very jitter immune, it was just easier to go Toslink so I don’t have to think about grounding. 

[asdf1000]

9 minutes ago, ecwl said:

it’s so much easier to say let me switch the SMPS to LPS so that I don’t have to worry about the high impedance leakage current noise

 

But this is the point I was making... John has never said that all LPS's measure better regarding this noise, than all SMPS's.

 

He can only comment on the ones he has measured - he hasn't measured every LPS and SMPS on the planet...  Same for Rob...

 

My point was they both will tell you there are some good SMPSs that measure better than some badly designed LPSs... and there are some good LPSs that measure better than badly designed SMPSs...

 

[asdf1000]

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

 

I just think people in the past have taken some of what each has said and tried to make a generalisation. 

 

To write it a different way: has Rob Watts measured an LPS-1.2 or JS-2 ? Has John S measured Chord DAVE's power supply? I haven't read anything anywhere that says yes to either question.

 

I'm happy to be proven wrong though. Maybe John S will chime in.

 

[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... ;)

[JohnSwenson]

8 hours ago, asdf1000 said:

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

 

I just think people in the past have taken some of what each has said and tried to make a generalisation. 

 

To write it a different way: has Rob Watts measured an LPS-1.2 or JS-2 ? Has John S measured Chord DAVE's power supply? I haven't read anything anywhere that says yes to either question.

 

I'm happy to be proven wrong though. Maybe John S will chime in.

 

Correct, I have never measured a Chord power supply.

 

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

1) leakage current

2) output impedance over frequency

 

#1: I have written MANY posts on this, in a nutshell there are two types of leakage current, high impedance, which only comes from SMPS and low impedance leakage which is found in both SMPS and LPS. Every SMPS I have ever tested has significant amounts of high impedance leakage. Fortunately grounding the output of the SMPS gets rid of almost all of this. Once you do the grounding SMPS and LPS are on a similar footing. Good SMPS have leas leakage then poor LPS and good LPS have less leakage than poor SMPS. So far with what I have tested the best LPSs have lower leakage than the best SMPS.

 

#2 output impedance is very important to digital. This is NOT a single number, it is a graph of output impedance VS frequency. MOST PS of either type have fairly high impedance at both low and high frequencies. Most SMPS to not have separate regulators AFTER the switching converter, and thus rely on how good the regulation is of the whole converter. Usually this is quite poor. To improve this you can make the switching converter system as a whole have a much higher bandwidth, which CAN be done but costs a lot of money, OR use a linear regulator after the Switching converter. Both approaches can radically improve the output impedance at the extremes, but increase cost and space.

 

Note that no test equipment manufacturer actually makes a power supply tester that measure output impedance VS frequency. If you want to measure this you have to design and build your own. Doing a good job of this is NOT easy or cheap. Thus VERY few power supplies have actually been tested for this. I have built several over the years and have tested some of both SMPS and LPS and the results are all over the map.

 

John S.

[skatbelt]

10 hours ago, asdf1000 said:

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

 

I just think people in the past have taken some of what each has said and tried to make a generalisation. 

 

To write it a different way: has Rob Watts measured an LPS-1.2 or JS-2 ? Has John S measured Chord DAVE's power supply? I haven't read anything anywhere that says yes to either question.

 

I'm happy to be proven wrong though. Maybe John S will chime in.

 

 

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.

[asdf1000]

10 hours ago, JohnSwenson said:

Correct, I have never measured a Chord power supply.

 

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

1) leakage current

2) output impedance over frequency

 

#1: I have written MANY posts on this, in a nutshell there are two types of leakage current, high impedance, which only comes from SMPS and low impedance leakage which is found in both SMPS and LPS. Every SMPS I have ever tested has significant amounts of high impedance leakage. Fortunately grounding the output of the SMPS gets rid of almost all of this. Once you do the grounding SMPS and LPS are on a similar footing. Good SMPS have leas leakage then poor LPS and good LPS have less leakage than poor SMPS. So far with what I have tested the best LPSs have lower leakage than the best SMPS.

 

#2 output impedance is very important to digital. This is NOT a single number, it is a graph of output impedance VS frequency. MOST PS of either type have fairly high impedance at both low and high frequencies. Most SMPS to not have separate regulators AFTER the switching converter, and thus rely on how good the regulation is of the whole converter. Usually this is quite poor. To improve this you can make the switching converter system as a whole have a much higher bandwidth, which CAN be done but costs a lot of money, OR use a linear regulator after the Switching converter. Both approaches can radically improve the output impedance at the extremes, but increase cost and space.

 

Note that no test equipment manufacturer actually makes a power supply tester that measure output impedance VS frequency. If you want to measure this you have to design and build your own. Doing a good job of this is NOT easy or cheap. Thus VERY few power supplies have actually been tested for this. I have built several over the years and have tested some of both SMPS and LPS and the results are all over the map.

 

John S.

 

Thanks John S! Yes I have read nearly all your posts on the topic.

 

I think a lot of people have generalised a lot of what you've said (that's not your fault or problem) but as you noted:

 

10 hours ago, JohnSwenson said:

Correct, I have never measured a Chord power supply.

 

10 hours ago, JohnSwenson said:

Good SMPS have leas leakage then poor LPS and good LPS have less leakage than poor SMPS.

 

10 hours ago, JohnSwenson said:

I have built several over the years and have tested some of both SMPS and LPS and the results are all over the map.

 

Having said that, I know the LPS-1.2 and and JS-2 are stellar.

 

[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.

[ecwl]

@DAVE JS2 I forgot to mention that even if you’re not totally ready to add a convolution filter to your system from Mitch Barrett, just measuring your system (through DAVE) with a calibrated microphone through Room EQ Wizard and taking out the bass peaks (if there are any) using the parametric EQ function of Roon would usually yield quite a significant upgrade in sound. 
 

of course for now, enjoy the JS2 upgrade. But if I were in your position and debating what to do next, I’d probably look to see if there are any bass peaks to tune out using parametric EQ in Roon. It’s free to do if you already have a calibrated microphone. 
 

by the way, all this talk about the great products from Uptone audio makes me want to upgrade from my LPS-1 to LPS-1.2. It is a great company

[skatbelt]

1 hour ago, DAVE JS2 said:

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.

 

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... :)

 

 

 

[jamesg11]

11 hours ago, asdf1000 said:

 

Thanks John S! Yes I have read nearly all your posts on the topic.

 

I think a lot of people have generalised a lot of what you've said (that's not your fault or problem) but as you noted:

 

 

 

 

Having said that, I know the LPS-1.2 and and JS-2 are stellar.

 

Yes, we assume JS uses his test gear thru product development, & owning both I know the ‘stellar’ results -

 

but what are the characteristic sonic traits of 1. & 2. above, particularly output impedance over frequency?

 

... given that I’m about to use a non-Uptone power supply ie non-JS-measured ...

of course, as always, I’ll know if the music sq deteriorates!

 

 

[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.