Another new USB regenerator: Lightspeed Revive

[mmerrill99]

Why don't you read what I said instead of following this path you have decided on and stop trying to belittle me and call me a liar and patronising me in your reply.

As you don,t seem to be able to read without twisting what I said I shall reiterate, the design was to show the isolation moats at the input and output of the board crossed by pi filters, the circuitry in the middle can be what you want it does not matter, it is the EMC (noise) isolation I was trying to show...

I have read what you posted & conclude that you don't seem to understand the concepts that are being discussed. USB regeneration/revive use USB hub chips which have no electrical isolation & never have there been any claim to such. You are the only one I've ever seen make this claim - " just replace the Adum with say a SMSC USB2412 and associated circuitry and you have a USB hub fully isolated."

 

This demonstrates a severe lack of understanding about USB, about isolation & about what is being discussed here.

 

Your side issues about moats have only any significance when using an isolator chip such as the ADUM where the two grounds, upstream & downstream, are electrically isolated within the chip.

As explained earlier everything I work on is covered by NDAs or other resirtictions I am just giving some ideas from the world of electronics I work in, you can check me out on line I am sure currently work at Quadra Solutions and I am on Linkedin, much better than calling someone a liar, just because I don't follow your viewpoint. Funny many clients use me because of my experience and knowledge in layout for signal integrity, low noise etc maybe there fools, they must be because they keep coming back.....

This is the first time I've heard of NDA with regards to yourself - so now you can't support any claims you make, I see?

 

I'm not calling you a liar, I'm just examining your posts for technical expertise & find none. I don't control the conclusions you or others draw from this.

 

Anyway more things to worry about in life than being patronised... my true thoughts would get me banned...The Fostex drivers I got at a very good price from Planet 10 as I only have one pair of the 208s I cannot compare them so cannot give an opinion on the effects of enable, I enjoy the speakers as a whole and they look funky so I am happy with my lot.

Hmmm, this is certainly not the impression you posted on DIYaudio where you wax lyrical about the effects of your ENabled Fostex drives - here

"

I was not disapointed, and have been quite vocular about my listening experience (on the CC thread) and the total involvment in the music I listen to and probably more important the music I dont normaly listen to..............

I cannot give a scientific explanation for what I hear, a more correct term would be what I DONT hear, but I am lucky to have two very good transducers either side of my head (a few hundred million years in development), linked directly to my brain, and what I hear is the music, and the emotion that the music ivokes in me.

I am not a clinical listener, I have tried but tend to drift off following some stanza, or following a paticular instrument as the mood takes me. And therin lies the beauty of what this combination of EnABLed FE207 in the Curvy Chang cabinets gives me, audio nivarna.

"

 

"

I know some people reading this thread are questioning how somthing so small and insignificant as

painted squares round a drivers edge could have any significant effect, and as the only real proof

of this effect is our hearing, as a reliable measuring system is yet to be devised or method formulated."

 

Interesting that you trust your ears in this quoted post but not in the above post "now is I realise how easily our perceptions can be fooled so dont take anything for granted."

 

Interesting how you accept the sonic improvements with ENabled drives when there is no measurement to support the claimed improvement yet you do the opposite when USB hubs are being discussed.

[marce]

I have read what you posted & conclude that you don't seem to understand the concepts that are being discussed. USB regeneration/revive use USB hub chips which have no electrical isolation & never have there been any claim to such. You are the only one I've ever seen make this claim - " just replace the Adum with say a SMSC USB2412 and associated circuitry and you have a USB hub fully isolated."

 

This demonstrates a severe lack of understanding about USB, about isolation & about what is being discussed here.

 

Your side issues about moats have only any significance when using an isolator chip such as the ADUM where the two grounds, upstream & downstream, are electrically isolated within the chip.

This is the first time I've heard of NDA with regards to yourself - so now you can't support any claims you make, I see?

 

I'm not calling you a liar, I'm just examining your posts for technical expertise & find none. I don;t control the conclusions you or others draw from this is fact.

 

 

Hmmm, this is certainly not the impression you posted on DIYaudio where you wax lyrical about the effects of your ENabled Fostex drives - here

"

I was not disapointed, and have been quite vocular about my listening experience (on the CC thread) and the total involvment in the music I listen to and probably more important the music I dont normaly listen to..............

I cannot give a scientific explanation for what I hear, a more correct term would be what I DONT hear, but I am lucky to have two very good transducers either side of my head (a few hundred million years in development), linked directly to my brain, and what I hear is the music, and the emotion that the music ivokes in me.

I am not a clinical listener, I have tried but tend to drift off following some stanza, or following a paticular instrument as the mood takes me. And therin lies the beauty of what this combination of EnABLed FE207 in the Curvy Chang cabinets gives me, audio nivarna.

"

 

"

I know some people reading this thread are questioning how somthing so small and insignificant as

painted squares round a drivers edge could have any significant effect, and as the only real proof

of this effect is our hearing, as a reliable measuring system is yet to be devised or method formulated."

 

Interesting that you trust your ears in this quoted post but not in the above post "now is I realise how easily our perceptions can be fooled so dont take anything for granted."

 

Interesting how you accept the sonic improvements with ENabled drives when there is no measurement to support the claimed improvement yet you do the opposite when USB hubs are being discussed.

 

You are calling me a liar and getting very personal, you are a bit of a bully I suspect.

managing noise isolation (NOISE ISOLATION) is critical whatever the design, read the phrase NOISE ISOLATION. That is part of what is being claimed, noise isolation I just pointed out that the layouts especially the jitterbug did not use techniques to isolate noise in fact there were many noise coupling mechanisms not catered for in the layout...

Now if you are so pathetic to go chasing old threads just to find something to have a go at me by that is your problem, you are a bully and a sad person it seems also... this is taking things to far on a personal level and has derailed what could have been a sensible discussion about isolating the noise, not galvanic isolation which does not guarantee noise isolation...

[marce]

The behaviour been shown towards me is rather worrying, that someone can go to such lengths to ridicule and discredit someone is rather strange and I can only hope that something is done about it...

Again noise isolation shown with the moats was used to isolate noise for many different types of connections where the grounds were all tied together, it is not only for USB (I have some caveats with USB and multiple common mode chokes in the data lines, but as said my longer response has been binned) but other signals as well, now mmerril99 has said that its useless unless an ADum device is used, hmmm! so the equipment that we originally used it on must be flawed as well as other equipment it has found its way onto over the last few years.... LOL

Again as stated earlier I mentioned how my views have changed as I started using more blind testing etc and question more the accuracy of my perceptions.

This has now become a personal attack on myself despite a request for this not to happen, I would like it to stop....

[Jud]

managing noise isolation (NOISE ISOLATION) is critical whatever the design, read the phrase NOISE ISOLATION. That is part of what is being claimed, noise isolation I just pointed out that the layouts especially the jitterbug did not use techniques to isolate noise in fact there were many noise coupling mechanisms not catered for in the layout...

 

* * *

 

galvanic isolation which does not guarantee noise isolation...

 

Would like to see more about this if you're up for it, both in general (noise isolation vs. galvanic isolation) and the types of noise (de-?)coupling mechanisms not done in some pieces that you feel would be effective.

[The Computer Audiophile]

Everybody wants to read about the topic and nobody wants to read about personal issues between members of the community. Please stick to addressing the issues pointed out by one another.

[mmerrill99]

marce, I'm just highlighting your inconsistencies.

 

This was your first post on this thread where you look for measurements to back up the listening impressions posted by many yet you are happy to laud the ENabled speakers which have no such measurements. Do you now want to disown those views about the ENabled Fostex drives?

 

In this post you bring up galvanic isolation, no one else did!! And you then go on to compound your misunderstanding with talk about noise coupling through & later on moats, etc.

 

And then you end with a cynical point "manufacturers jump on the cash cow that has been created, unnecessarily."

 

Now you are complaining when I question your technical knowledge & your consistency demonstrated in your posts - calling it personal?

 

I am amazed at the rhetoric surrounding what are basic USB hubs and the magic they seem to perform... I would like to see some decent information such as eye diagram etc...

Gavlanic Isolation...

https://en.wikipedia.org/wiki/Galvanic_isolation

 

Unless the layout is done very carefully with extra filtering then galvanic isolation does NOT stop noise, noise will still couple through. none of the layouts I have seen so far show this concern. Again without data you don't know whether your USB output is that bad...

 

Impedance matching... LOL the USB guidelines state all USB to be 90 ohm diff pair routed, nothing special and most if not all layouts follow the guidelines...

 

Signal Integrity, show me plots and data that show this is greatly improved and that the signal before was so bad...

This proliferation of USB hubs (the same chips can be found in many self powered USB hubs that are no different, just don.t have pages of rhetoric to market them) has come as no surprise as more manufacturers jump on the cash cow that has been created, unnecessarily.

[mmerrill99]

Would like to see more about this if you're up for it, both in general (noise isolation vs. galvanic isolation) and the types of noise (de-?)coupling mechanisms not done in some pieces that you feel would be effective.

Yes, I too would like to see marce's analysis of the Revive or Regen layout. Maybe he could also analyse the Intona layout which actually claims galvanic isolation?

[PhilR]

This could be an interesting discussion, bummer it has to get so personal.

 

Face to face interaction: "I disagree with what you are saying. Let me detail why I disagree and show you what I think is a better solution.

 

Interwebz: I disagree with what you are saying. I'm going to spend the next few paragraphs questioning your experience and character while digging up unrelated items to show everyone what an idiot I think you are. After that, I can detail why I disagree with you and show you what I think is a better solution.

[mmerrill99]

The topic is the Revive - another USB hub style device.

 

marce's first post on it is copied above & I detailed why I disagree with him.

 

- None of these USB hub devices have anything to with galvanic isolation. He brought this into the frame, incorrectly.

- the point she made about layout are generally accepted good practise & nothing to do with galvanic isolation, "noise coupling through"

- his demand for plots to show the effect of these USB hub devices I contrasted with his lack of such a demand with his ENabled Fostex drives used in his speakers - speakers that he showed a picture of & I commented on.

- his cynical comments "come as no surprise as more manufacturers jump on the cash cow that has been created, unnecessarily." I also disagreed with as it is built on the above strawman arguments

 

I hope that clarifies & succinctly expresses my points?

 

As to a better solution, there are none to offer - all I offer is a technical analysis of his criticisms of USB hub devices which I believe is worthwhile if mis-information (either intended or not) is not to be allowed to abound on threads?

[marce]

marce, I'm just highlighting your inconsistencies.

 

This was your first post on this thread where you look for measurements to back up the listening impressions posted by many yet you are happy to laud the ENabled speakers which have no such measurements. Do you now want to disown those views about the ENabled Fostex drives?

 

In this post you bring up galvanic isolation, no one else did!! And you then go on to compound your misunderstanding with talk about noise coupling through & later on moats, etc.

 

And then you end with a cynical point "manufacturers jump on the cash cow that has been created, unnecessarily."

 

Now you are complaining when I question your technical knowledge & your consistency demonstrated in your posts - calling it personal?

 

The Adum devcies are used to galvanicly isolate the signal source and destination...

 

You wont give it a f****** rest will you....

 

Unlike many I question what i have been led to believe regarding, bringing up one post ihas been done just to have a go, you cant stop....

 

 

 

in this instance we are discussing mainly the high frequency noise generated in all digital systems, PCs being one of the worse example due to quite often cost restraints and the consumers demand for products at a price. This noise can be a major EMC problem especially where cables are connected to equipment that could act a antennas, so there are numerous techniques to minimise this possible problem one of the most common being a ferrite bead either on board or for the complete cable. The problem we were faced with was achieving up to 18GHz immunity and also the fact that any excess noise wont just upset the system but could be detected by hostiles or set off remotely rf triggered explosives, so as stated the customer hired an RF engineer and myself to play about with layouts (on my side) and various circuit options. We came up with the definitive moat with signals crossing using some form of HF attenuation the best option being a pi filer consisting of two MLCC caps and a chip ferrite bead, giving the best signal integrity and noise immunity, thus isolating the cable assembly (in terms of noise) as much as possible. The main coupling mechanism for high frequency noise on PCB assemblies is capacitive coupling so avoiding this from input to output is critical. The first product that came to light was the Jitterbug that made major claims for noise isolation, yet even a cursory glance at the PCB showed a basic layout with no thoughts for this coupling so the device cannot do what it claims effectively. Now my view on this is if you are going to reduce the noise then you should be pedantic about every aspect of the design especially the layout where many of the problems can be solved by good layout practice or greatly increased by crappy layout.

More later I have to finish a re-design that some daft bugger has asked me to do as the initial design was so bad the on board EMC was buggering up the RF link (mobile runway lights, 3 SMPSs supplies for the big LEDs), so daft bugger asked me to do it thinking I know what I am doing... better put him and a few others in contact with my new best internet fiend mmerrill99 to put things straight... LOL

[The Computer Audiophile]

What's going on here? Are your egos just too big to ignore personal comments and stick to the topic? Nobody cares if you get the last word. In fact, attempting to get the last word and respond to everything personal is turning everyone off. I'd love to see this conversation be able to educate people who find this thread in two years via Google. So far it appears the participants are only willing to educate us in personal attacks and a willingness to tell the other guy to go look it up.

 

Come on guys. I have respect for all of you ad your knowledge and willingness to contribute to the community. I just hope you can put the personal stuff in the past.

[PeterSt]

Maybe in general, but a tiny little bit addressing Merrill :

 

It is quite easy to get confused between galvanic isolation and "getting rid of noise" which can be done partly by means of isolation (the emergency solution), but better be by "guiding out" (the decent solution). Not sure whether I would call that "isolation of noise" but think noise shaping and you're close.

 

In the other thread we had the same problem. Isolation is to take out noise (which is the perception but does not prove to be so at all) while taking out the noise (isolate it else where if you like) can go by means of separate ground planes and such.

 

What could be required next is not take all too literal and catch people on their words and wording. Btw I would be the first where that can happen easily because of my stupid English constructed sentences.

 

Let me put forward this one :

When we want to get rid of noise, we just want to get rid of noise - period. We per se do not want to isolate (this is not a purpose in itself) although it may help. One thing : you won't know in advance how destructive that is (EMI stuff). Or maybe those in the field really know - I do not.

I always refer to the law of conservation of energy. Think of that when you think of isolation and so-called (hoped for) getting rid of things (energy !). It can not exist ...

[mmerrill99]

Maybe in general, but a tiny little bit addressing Merrill :

 

It is quite easy to get confused between galvanic isolation and "getting rid of noise" which can be done partly by means of isolation (the emergency solution), but better be by "guiding out" (the decent solution). Not sure whether I would call that "isolation of noise" but think noise shaping and you're close.

Yes, let's clear up the definition of what "noise" is being talked about here. There is "audibly perceived noise" & there is "electrical noise". Now "audibly perceived noise" is tricky because it's not always perceived as noise - it can alter what we hear. In the case of the abtr's "jitter" thread what he was actually experiencing was the influence of ground noise coming through USB on the playback & hence on his auditory perceptions. But he didn't experience it as noise, as such, he experienced it as a lifelessness, a flat portrayal of the music when compared to CD playback.

 

So let's clarify this some more, this type (or level/frequency) of ground noise only arises when a signal is being processed - it won't be heard if you put your ear to the speaker with the vol turned up full when digital silence is playing - it's only audible when music signal is playing & hence it gets mushed up with the music signal & is not perceived directly, only in it's perceived effect on the music.

 

Now electrical noise is the culprit here, IMO because it is effecting the reference voltage that all devices use i.e ground. So what causes non-zero voltages to appear on this reference (ground)? Lots of possibilities abound - one is ground currents from ground loops (as in abtr's case), another is noise generated by chips which enter the ground & there are many others, including EMC.

 

So what the USB hub devices are premised to do is address the self noise created by the USB receiver chip when handling a USB signal - it is postulated that the less well-formed this USB signal, the higher the self-noise & the greater the amount of fluctuating noise on the ground. So how does this noise effect the sound & would isolation after the USB receiver not solve the issue? No, because the noise has already been embedded in the signal that is output from the USB receiver chip to the rest of the system.

 

In the other thread we had the same problem. Isolation is to take out noise (which is the perception but does not prove to be so at all) while taking out the noise (isolate it else where if you like) can go by means of separate ground planes and such.

 

What could be required next is not take all too literal and catch people on their words and wording. Btw I would be the first where that can happen easily because of my stupid English constructed sentences.

 

Let me put forward this one :

When we want to get rid of noise, we just want to get rid of noise - period. We per se do not want to isolate (this is not a purpose in itself) although it may help. One thing : you won't know in advance how destructive that is (EMI stuff). Or maybe those in the field really know - I do not.

I always refer to the law of conservation of energy. Think of that when you think of isolation and so-called (hoped for) getting rid of things (energy !). It can not exist ...

Again, you have lost me, sorry!

We want to get rid of the audible effect of what we believe is noise on the ground reference when critical points in the processing system. There are a number of ways to address this & none of them have proven to be 100% effective so far i.e we haven't achieved 100% immunity from upstream changes in USB audio. USB hubs seem to deal with a certain element. USB isolation devices before the USB receiver deal with a different source of noise. Isolation devices after the USB receiver (on the I2S lines) try to deal with downstream noise.

 

None of these confer immunity & hence we might infer that electrical ground plane noise is still an issue.

[PeterSt]

So let's clarify this some more, this type of noise only arises when a signal is being processed - it won;t be heard if you put your ear to the speaker with the vol turned up full when digital silence is playing - it's only audible when music signal is playing & hence it gets mushed up with the music signal & is not perceived directly, only in it's perceived effect on the music.

 

No real disagreement anywhere that I can see at first glance (!). But the above ...

I just don't recognize that and don't know what to do to imply that. However, this is certainly true in digital signals, where even the lowest level of noise can alter the timing. And the data itself implies the noise (1's draw more current than 0's).

 

Maybe not worth while further discussion in here, but always nice to learn what source could imply what you are posing ?

Thanks.

[mmerrill99]

 

No real disagreement anywhere that I can see at first glance (!). But the above ...

I just don't recognize that and don't know what to do to imply that. However, this is certainly true in digital signals, where even the lowest level of noise can alter the timing. And the data itself implies the noise (1's draw more current than 0's).

 

Maybe not worth while further discussion in here, but always nice to learn what source could imply what you are posing ?

Thanks.

Yes, we are talking about digital audio. I don't know what you mean by "what source could imply what you are posing"?

[atsq]

While I appreciate everyone is entitled to their opinion, I find that the bits are bits conversations tend to always derail the primary topic of discussion. I only managed to read about one and a half pages of impressions on the actual topic before it was hijacked for yet another endless debate.

 

Even though they don't realize this, I find that ones and zeros sceptics tend to add very little value to the conversation (plus they always say the same stuff). If you don't or can't tell the difference between products, just say it once in a succinct matter and let that be that. Your opinion is noted.

 

Anyway, I liken it to Atheist/Evolution evangelists constantly visiting churches and interrupting a mass or sermon which the congregation are trying to listen to. In the end everyone leaves the church because the place has been hijacked for another agenda and the people who attended could not get what they came for. Maybe that was the intention of the sceptic in the first place?

 

To those who laugh at me likening this hobby to a religion, what can I say? When I can hear the "miracles" I'm a believer.

 

That was just my long winded way of saying... can we please just keep discussing the revive?

 

I for one stayed in this hobby long enough that recently I could actually tell the difference in power cables (something I was a sceptic of even when I was buying expensive USB cables).

 

My Macbook Pro Retina's USB port is noisy and the regen makes a HUGE difference that even untrained ears can notice when I plug it in. The soundstage height alone changed SO MUCH when I used the regen (connected to teradak LPS and Curious regen link).

 

I came here to read about the Revive as it sounded like an interesting alternative and I want to thank those who managed to actually contribute to the topic prior to the hijacking.

[stuck limo]

If anyone has one of these to sell, I'd probably buy it off you....I've got one but would like a second.