Is Melco the new Hugo...

Yes, galvanic isolation is about providing a discontinuous path between two circuits. It works by effectively eliminating the current flow from one circuit to another. 

RF current is a strange beasts and will couple via electro magnetic induction across distances and across DC discontinuities or capacitors. So with RF one needs to locally create low impedance paths to ground at the frequencies of concern, as well as as careful physical design to minimise the effects of RF coupling. Indeed such decoupling could well be used the DAC side of the galvanic isolator.

Now Mr Watts pays careful consideration to RF filtering and decoupling in his designs, however in the Hugo there was, I understand, an issue with noisy ground current passing through a host computer to the DAC via USB and no doubt into the amp chain.. ( I have heard it on mine). By galcvanically isolating he stopped thee flow of this earth noisy current.

However RF noise emissions should they be prevalent will still interact with the audio circuitry. I still recommend a ferrite choke on the USB lead to impede common mode RF currents.

Simon

HH in a sense of sweet irony, going back to you original post (which was about flavours of the month not so much the two items mentioned), on Melco twitter feed is an image of Melco feeding a Hugo (with a Blu-ray acting as a ripper direct to Melco) on their own demo stand at Bristol...

Wow. I hope there are medics on hand to help those fainting with excitement! 

Simon-in-Suffolk posted:

Yes, galvanic isolation is about providing a discontinuous path between two circuits. It works by effectively eliminating the current flow from one circuit to another. 

RF current is a strange beasts and will couple via electro magnetic induction across distances and across DC discontinuities or capacitors. So with RF one needs to locally create low impedance paths to ground at the frequencies of concern, as well as as careful physical design to minimise the effects of RF coupling. Indeed such decoupling could well be used the DAC side of the galvanic isolator.

Now Mr Watts pays careful consideration to RF filtering and decoupling in his designs, however in the Hugo there was, I understand, an issue with noisy ground current passing through a host computer to the DAC via USB and no doubt into the amp chain.. ( I have heard it on mine). By galcvanically isolating he stopped thee flow of this earth noisy current.

However RF noise emissions should they be prevalent will still interact with the audio circuitry. I still recommend a ferrite choke on the USB lead to impede common mode RF currents.

Simon

 

 

 

 

 

I've got a USB regen at the Hugo end, which breaks the power feed from the Mac, and a Jitterbug at the Mac end.  I could hear an improvement with both and the Jitterbug was very impressive.  I've also got chokes all over the place but I have to say I've never heard any difference after installing them.  I moved the Mac from the rack, where it was next to my Hicap DR, further into the room last week at the end of a Wireworld USB cable and there was again a slight drop in the noise floor and a little more clarity.  I may change the Mac so that I can use a good quality power supply but apart from that I will probably leave well alone now as it sounds superb. 

Simon-in-Suffolk posted:

Yes, galvanic isolation is about providing a discontinuous path between two circuits. It works by effectively eliminating the current flow from one circuit to another. 

RF current is a strange beasts and will couple via electro magnetic induction across distances and across DC discontinuities or capacitors. So with RF one needs to locally create low impedance paths to ground at the frequencies of concern, as well as as careful physical design to minimise the effects of RF coupling. Indeed such decoupling could well be used the DAC side of the galvanic isolator.

Now Mr Watts pays careful consideration to RF filtering and decoupling in his designs, however in the Hugo there was, I understand, an issue with noisy ground current passing through a host computer to the DAC via USB and no doubt into the amp chain.. ( I have heard it on mine). By galcvanically isolating he stopped thee flow of this earth noisy current.

However RF noise emissions should they be prevalent will still interact with the audio circuitry. I still recommend a ferrite choke on the USB lead to impede common mode RF currents.

Simon

Simon, Rob Watts is absolutely clear that as far as the Dave is concerned "RF noise from the source can't get into Dave".  Are you saying it can?  If so, how do you know?

Absolutely of course  it can depending on source, positioning, and extent of EM radiation.. . I think he is talking about his decoupling and its effectiveness and mitigating  dirty ground loops, and indeed he did this excluding USB to great effect in the Hugo and now with the USB with DAVE. Also a relatively clean source, such as the Melco purportedly  is, probably is dealt with very effectively with the DAVE decoupling.. I suspect why one hears that the two are demoed together at the moment.

PS if the perfect decoupling method to banish RF Electro magetic radiation had been some how invented, this would obsolete a whole set on standards and safeguards on EM emissions at a stroke and I'm sure Mr Watts would be significantly wealthier and even more influential than he is, not too mention such invention would be patentable and licencesd to consumer and commercial electronic devices the world over.

Simon

likesmusic posted:

Simon-in-Suffolk posted:

Yes, galvanic isolation is about providing a discontinuous path between two circuits. It works by effectively eliminating the current flow from one circuit to another. 

RF current is a strange beasts and will couple via electro magnetic induction across distances and across DC discontinuities or capacitors. So with RF one needs to locally create low impedance paths to ground at the frequencies of concern, as well as as careful physical design to minimise the effects of RF coupling. Indeed such decoupling could well be used the DAC side of the galvanic isolator.

Now Mr Watts pays careful consideration to RF filtering and decoupling in his designs, however in the Hugo there was, I understand, an issue with noisy ground current passing through a host computer to the DAC via USB and no doubt into the amp chain.. ( I have heard it on mine). By galcvanically isolating he stopped thee flow of this earth noisy current.

However RF noise emissions should they be prevalent will still interact with the audio circuitry. I still recommend a ferrite choke on the USB lead to impede common mode RF currents.

Simon

Simon, Rob Watts is absolutely clear that as far as the Dave is concerned "RF noise from the source can't get into Dave".  Are you saying it can?  If so, how do you know?

I believe Alan Shaw of Harbeth says that all amps sound the same, do you believe him too?  They are both trying to sell their products

Likesmusic, can  I ask you a personal question, have you ever studied electronic engineering or applied its engineering design principles it for a living? Just curious whether you have any deep or even moderate understanding of the design principles involved? Absolutely no issue if you haven't. But if not may I suggest in the world of engineering its best to be wary of anyone selling a technically engineered product talking about absolutes... engineers (should) always understand their design limitations.

Simon-in-Suffolk posted:

Likesmusic, can  I ask you a personal question, have you ever studied electronic engineering or applied its engineering design principles it for a living? Just curious whether you have any deep or even moderate understanding of the design principles involved? Absolutely no issue if you haven't. But if not may I suggest in the world of engineering its best to be wary of anyone selling a technically engineered product talking about absolutes... engineers (should) always understand their design limitations.

I know for sure that Rob Watts has studied electronic engineering. I know for sure that Rob Watts has applied it's engineering design principles for a living, I know  for sure that Rob Watts has a deep understanding of the design principles involved. I know for sure that Rob Watts designed the Dave, Hugo TT and 2Qute. I know for sure that Rob  has stated that RF noise from the source can't get into Dave. If you are suggesting he is mistaken, wrong or lying then you should have the courage to confront him directly. Making a personal attack on me and my education will not draw attention away from the fact that you are making statements about a product that you have neither owned nor measured and which directly contradict the designers own claims. If Rob is the sort of person that would lie about a product for marketing reasons, he would have lied about the unisolated USB inputs of the Hugo and Dave. He did not. He seems to be fully aware of his products' limitations. We all have limitations. 

Simon's point is simply that the designer cannot state categorically that RFI from the source cannot get into his DAC. He has not tested every single scenario with every single source, so there is no foundation for such an absolute statement. It's just marketing puff, and if anyone took it to the ASA it would very likely need to be changed. 

Hungryhalibut posted:

Simon's point is simply that the designer cannot state categorically that RFI from the source cannot get into his DAC. He has not tested every single scenario with every single source, so there is no foundation for such an absolute statement. It's just marketing puff, and if anyone took it to the ASA it would very likely need to be changed. 

Indeed.

Chord, and no doubt Naim and some others, would have sought to minimise RFI. Whether this is enough or not, depends on the rest of a set up, ears, and preference.

Hungryhalibut posted:

Simon's point is simply that the designer cannot state categorically that RFI from the source cannot get into his DAC. He has not tested every single scenario with every single source, so there is no foundation for such an absolute statement. It's just marketing puff, and if anyone took it to the ASA it would very likely need to be changed. 

Why don't you or Simon take the issue up directly with Rob on the forum where he posts? Or take him to the ASA if you believe he spouts marketing puff? Neither you nor Simon have tested the Dave with any source whatsoever, so you have absolutely no evidence that its performance can be improved by putting a ferrite on the USB lead as Simon suggests. I'd be a little surprised if Mr Watts had overlooked such a simple way of improving his designs. He has recommended the Olimex for Hugo users, so he is perfectly open to non-Chord enhancements.

Likesmusic, why are you bothered?  If you believe that what Rob says is the literal truth then both you and he can be happy.  Does it matter if others don't accept it?  lots of companies makes lots of claims for their products, if you choose to believe them all then I'm sure you will be very popular in sales rooms but it doesn't change your belief or the truth if others don't agree.  Who cares?  Listen to some music and chill 

It seem the more one get into digital music the more it gets complicated. Was analog that bad? I would happily stay with analog but they keep playing digital music on FM radio stations... One step forward, one step backward. Money talks.

likesmusic posted:

Simon-in-Suffolk posted:

Likesmusic, can  I ask you a personal question, have you ever studied electronic engineering or applied its engineering design principles it for a living? Just curious whether you have any deep or even moderate understanding of the design principles involved? Absolutely no issue if you haven't. But if not may I suggest in the world of engineering its best to be wary of anyone selling a technically engineered product talking about absolutes... engineers (should) always understand their design limitations.

I know for sure that Rob Watts has studied electronic engineering. I know for sure that Rob Watts has applied it's engineering design principles for a living, I know  for sure that Rob Watts has a deep understanding of the design principles involved. I know for sure that Rob Watts designed the Dave, Hugo TT and 2Qute. I know for sure that Rob  has stated that RF noise from the source can't get into Dave. If you are suggesting he is mistaken, wrong or lying then you should have the courage to confront him directly. Making a personal attack on me and my education will not draw attention away from the fact that you are making statements about a product that you have neither owned nor measured and which directly contradict the designers own claims. If Rob is the sort of person that would lie about a product for marketing reasons, he would have lied about the unisolated USB inputs of the Hugo and Dave. He did not. He seems to be fully aware of his products' limitations. We all have limitations. 

 

Likesmusic, i certainly didn't mean to insult you - and i tried to choose my words carefully - but perhaps being a professional engineer myself sometimes we or certainly I am not  the most eloquent...  my point is that no you can't completely  stop RF radiation affecting electronics - all you can do is minimise it and harden the electronics. However Rob Watts I'm sure is talking about dirty ground currents not RF electro magnetic fields - but being a Chord customer myself I certainly know he has worked well to reduce the impacts of RF and RF intermodulation in his designs. But from my perspective this is nothing specific about Rob Watts or his particular designs - its more about engineering design principles. The best way to reduce RF is to try and reduce emitted RF noise currents at source... once you have created RF noise its very hard to control where it goes or doesn't go - just look at the effects of Powerline Adapters for example.

A consumer electronics hifi designer who has developed some ingenious ways to mitigate RF contamination in analogue audio designs is Denis Morecroft - he certainly is worth speaking to if you ever get the chance - very interesting.

You see RF mitigation and isolation of USB are really two separate matters (in my world at least) - and thats why I think, perhaps with the greatest of respect, you might have mixed the two together - albeit perhaps Rob Watts used 'RF' to refer to high frequency noise appearing on the USB ground current and hasn't perhaps helped the common understanding

Once again, I'm sorry if you were offended by my choice of words I just try and explain it as it is or how I see it - and perhaps I am a little too direct sometimes.... perhaps Rob Watts is better at using softer words..

Simon

cat345 posted:

It seem the more one get into digital music the more it gets complicated. Was analog that bad? I would happily stay with analog but they keep playing digital music on FM radio stations... One step forward, one step backward. Money talks.

If only - I have had my worst experience of RF intermodulation with analogue sources and not digitial. Digital does tend to be a little more robust.

But I agree VHF FM is hard to beat as a source.

S

Melco ripping includes Gracenote metadata/tagging. Some interesting online Melco threads where the breakdown of what it does is examined as others work out why it works when in essence its just a bunch of drives with a motherboard, Linux OS and a case.

In what I have read pretty much everyone is agreeing the Melco works, and works very very well (Devialet, Linn chat rooms and others), why it works so well is the head scratching part and some more knowledgeable chaps online are really digging.

It had an app called Melco HD but was removed while it is re-written. Control points for the UPnP while in direct mode have helped me to control the music library remotely while in direct mode.

New Linn Kazoo app is being tested.

Examples of online chatter on Melco :

These Melco guys are serious, they use separate Marvell 88E family GbE transceiver chips for each Ethernet port - a primary ‘1514 chip network facing, and a secondary ‘1518 chip DAC/Player facing (at least on the N1Z). Nice.

 The main CPU is a Marvell 88F6 family SoC (ARM-compliant). The motherboard has Buffalo stamped all over it, so I’m guessing it has the same OS as Buffalo’s LinkStation NAS; Linux based like pretty much every other NAS.

Dan43, I will see if I can borrow a Melco (for UPnP) and compare to my optimised RPi mk1 and sniff the data... The TCP behaviour does affect how Naim streamer's sound in my experience. I will what if any differences are.. Just need a free weekend when my local emporium let me borrow it.

Simon

I had an interesting chat with Alan Ainslie (the man behind the Melco) at the Bristol show yesterday. He showed me how easy it is to update the software (online or USB) and told me about some interesting future developments including attaching cheap DVD/Blu-Ray drives via USB and adding Asset. They are pushing the N1ZH, which is an N1ZS with 6tb hard drive instead of SSD.

Keith 

It'll be good to get your feedback Simon once you do test. There is an online thread where the owner of N1A really strips it down and looks at the motherboard etc happy to link it here but as with any thread you do need to go through the few pages that now exist to find the good posts. I think it is worth a read as it is more tech based on whats its perhaps really doing.

Simon-in-Suffolk posted:

Dan43, I will see if I can borrow a Melco (for UPnP) and compare to my optimised RPi mk1 and sniff the data... The TCP behaviour does affect how Naim streamer's sound in my experience. I will what if any differences are.. Just need a free weekend when my local emporium let me borrow it.

Simon

Ha! I'm afraid I've still got it Simon, and they're not getting it back! (Actually, I'll be dropping it back on Tuesday, but I do intend to order one).

Dan43, could you give me a clue within forum rules where I might find this thread? I have a little pet theory.. want to hear from another Melco user who has also a RPi mk 1 running Asset.

Tony, thanks for the heads up 

KRM posted:

I had an interesting chat with Alan Ainslie (the man behind the Melco) at the Bristol show yesterday. He showed me how easy it is to update the software (online or USB) and told me about some interesting future developments including attaching cheap DVD/Blu-Ray drives via USB and adding Asset. They are pushing the N1ZH, which is an N1ZS with 6tb hard drive instead of SSD.

Keith 

Thanks Keith,

Yes the BR/DVD rips with Gracenote metadata also I believe, new app coming soon is mentioned, MinimServer runs on Melco but is strictly beta for now. One guy online swapped the N1A 2 x 2TB drives for 2 x 4TB HDD drives and it was working fine, using same Seagate drives as in N1A.

Its a piece of kit that appears to be gaining traction, certainly a lot of Devialet & Linn owners have now bought in.

Simon I have put my email in my profile page quickly, and will delete in a bit, feel free to email I'll then send a link over privately.

Apparently, the Melco always ships with the default Twonky server, but users or supplying dealers can easily install Minimserver and, hopefully in future, Asset.