[JoeBorn]

You have previously discussed the Neuros devices here, I hope you won't view this as spamming your forums.

I'm posting on behalf of Neuros because we wanted to invite your input into our development process. We are currently in the process of developing two new products that may be of interest to the folks here. The first is the Neuros 3 and the second is the next generation of our PVP series, called the 442.

Both of these product will be targeted to the high end segment of the market and we'd like your input on SQ issues I/O etc.

We are currently in the process of creating development boards that will allow developers to get a jump on developing for our players, which are all open source and built on Linux. We are currently in the process of developing the hardware for these boards. I know you all have strong opinions about codecs, gapless and other software issues, but right now we're resolving the hardware specs.

Here's what we have Burr Brown ADC-DAC capable of 24 bit audio at 96KHz
I also am using a separate PLL to generate the sample rate clock
and making sure that at least the hardware is ready to handle SA-CD quality in all its glory
S/PDIF output only
LINE-IN for recording (requires an external mic pre-amp)

As you can see, It's really intended to be a high end portable audio player not a DAT recording replacement per se.

You can read the logs of a recent discussion between myself and hardware engineer below


http://open.neurosaudio.com/files/neuros.09-10.log


BTW you can monitor and participate in these discussions in realtime on #neuros IRC channel on freenode. Again, our product development process is an open one that we welcome your input on.

We would love any feedback and particuliarly on the hardware side since that's what we're working on right now. Thanks in advance for your help

Joe Born
Neuros Technology
Jborn at neurosaudio.com

 

[austonia]

about the nueros 442, perhaps you can clear this up... the player (442) that you show here:

http://neurosaudio.com/store/prod_442.asp

...looks to be the same as a generic (non-branded) chinese player we (dapreview) found at CES 2005:

http://www.dapreview.net/comment.php?comment.news.1700

aka, the Sampo PXD1 that was seen at Computex 2004.

http://pc.watch.impress.co.jp/docs/2004/0608/sampo.jpg

at least, the case and GUI appear the same. are we indeed talking about the same device, but with Neuros branding..? are there any differences in the device that you are offering?

thanks

edit: also, am i right to assume this uses a 2.5-inch hard drive? i remember it being a bit bigger than PMPs that use the 1.8-inch variety. if so, is there any reason why the user could not swap out the HD for a larger capacity?

 

[Jazper]

ok I'm going to be frank here: I think you're barking up the wrong tree.

First a high end portable needs to at least have some sort of analog output, not everyone carries around a portable dac to interface with toslink or SP/DIF. You don't need a dac if you're just outputting digital.

Second a high quality recording/playback device needs to get power from somewhere.

Power is a concern. Power is a huge concern for a portable device, a measly 35mA consumption will kill a 350mA battery in 10 hours. If you're planning a hard drive (with at least 100mA consumption) and a dac with at least 30mA, an adc with at least 30mA consumption a cpu with 50mA and other bits and pieces like recievers/transmitters for outputs that quickly adds up. How do you plan to fuel this thing?

DAC chip wise (if you are going with a dac) I'd try and go with something that sounds as neutral as possible, my choice, something like a wolfson WM4780. BB and Crystal are laid back and solid state glary respectively. Or try and balance it, for instance if you go a bb dac, complement it with a crystal headphone driver or a IT tpa6120a2, or something similar.


Clocking wise, (while I'm sure this has been done before) I'd suggest going with dual oscillators, and have a chip split the difference between them. High accuracy watches use thermal compensation to keep their high speed quartz in check, perhaps you could implement something similar.

thoughts... read into them what you will.. I may join the irc channel sometime

 

[austonia]

jazper, "barking up the wrong tree" ..? what? he's asking Head-Fi for input about building an audiophile-quality DAP. this is exactley the place to be asking about that.

and why do you even bother to mention that it would suck with a 350ma battery? of course it would have a higher-capacity battery. the measliest battery in any DAP that I know of is the 800ma one in the original iPod Mini. Most players have a battery with 1000-1400ma or more.

 

[Jazper]

Quote:

Originally Posted by austonia jazper, "barking up the wrong tree" ..? what? he's asking Head-Fi for input about building an audiophile-quality DAP. this is exactley the place to be asking about that. and why do you even bother to mention that it would suck with a 350ma battery? of course it would have a higher-capacity battery. the measliest battery in any DAP that I know of is the 800ma one in the original iPod Mini. Most players have a battery with 1000-1400ma or more.

Well I think he's trying to accomplish too many things at once.

The dap with the features he's talking about (ADC/DAC/Hard drive) is likely to consume in the order of 200-500mA. With a 1200mA battery that's 4~ hours playback on average.

I think one should really think about either having a high quality playback device or having a high quality recording device.. when you try to combine the two you often fail unless you have a dsp that can do both that consumes bugger all power.

 

[austonia]

jazper, there's only about 500 portable digital player/recorders already on the market here and abroad. and they have plaback times ranging from a few hours on the crap end to 35 hours for the double-battery'd versions (iaudio X5L). no kidding. i recall archos had the first player/recorders back in 2001.


edit: and there are already some high-end types from edirol, marantz, and m-audio.

http://www.edirol.com/products/info/r1.html
http://www.m-audio.com/products/en_u...2496-main.html
http://www.d-mpro.com/users/folder.asp?FolderID=3507
http://www.aaton.com/products/sound/cantar/index.php (lol.. not so portable)

 

[gerG]

Hi Joe, and welcome to head-fi!

I have been hoping for a player that will do what I now use a laptop for. My wishlist:

Digital out via toslink. I saw that you listed s/pdif, but not which format.

A high grade internal dac sounds tempting, but what sort of output connectors are you considering? If it is the ubiquitous 1/8" mini plug I don't think that it is even worth the trouble.

Ruggedness is a priority for me. I treat my gear very carefully, but if I happen to drop it I want it to bounce without a sound, and not clatter and absorb the shock through the body. Integrated corner bumpers are highly recommended.

I personally don't care if it is too big to fit in a pocket. I have smaller players for the super-portable needs.

Of course, with a high quality dac you could just build in an equally high quality headphone amp and eliminate the need for extra boxes and cables. Lots of good options hereabouts. Can you stuff a PPA circuit in there?

I know that you asked about hardware, but AAC capability would be a big plus (as would ALAC).

User changeable HD and battery pack would also win you points with everyone.

If it were me, I would make car integration a huge priority. A bit different set of needs, but a huge market. I would love to have a wireless enabled device in the car that I could access from a computer in the house to change out tunes remotely, without even bringing the device out of the garage.


OK, I am starting to drift toward the fringe here, time to stop for now. Thanks for asking!


gerG

 

[JoeBorn]

Quote:

Originally Posted by austonia about the nueros 442, perhaps you can clear this up... the player (442) that you show here: http://neurosaudio.com/store/prod_442.asp ...looks to be the same as a generic (non-branded) chinese player we (dapreview) found at CES 2005: http://www.dapreview.net/comment.php?comment.news.1700 aka, the Sampo PXD1 that was seen at Computex 2004. http://pc.watch.impress.co.jp/docs/2004/0608/sampo.jpg at least, the case and GUI appear the same. are we indeed talking about the same device, but with Neuros branding..? are there any differences in the device that you are offering? thanks edit: also, am i right to assume this uses a 2.5-inch hard drive? i remember it being a bit bigger than PMPs that use the 1.8-inch variety. if so, is there any reason why the user could not swap out the HD for a larger capacity?

The 442 is based on that product, although we have made a number of changes to it since then.

But actually, that's not the product we are talking about here. There are two products that are pertinent to this discussion. The Next generation 442 and the Neuros 3.

The 442-320, the next version of the 442, we intend to continue to use the same housing above, although we'll make some modifications to the mechanicals like on the rocker switch. However, the hardware inside will be completely redesigned using the TI DM320 chip instead. The software will be virtually redesigned from scratch.

The Neuros 3 (N3) is a completely new unit focused on audio and designed from scratch. It is doubtful (although possible) that we'll use an off the shelf housing, the insides will be designed completely from scratch.

the specs for the N3 can be found at http://www.theneuros.com/index.php/C...map:Neuros_III

and the development board that will be used for developers for the new 442-320 (some folks call the 443 for short) is described here

http://www.theneuros.com/index.php/4...per_Board_Spec

Since these devices are being designed from scratch, that's where the SQ issues related to hardware are coming up.

 

[JoeBorn]

The 442-320 will use a 2.5" Hard Drive and will currently support up to 100GB

and the Neuros 3 will use a 1.8" Hard Drive supporting up to 60GB

 

[gerG]

Hmmm, the more I think about it, the more I like the idea of a high end amp module that could be swapped out/upgraded. It would require an internal docking bay and standardized connector, but it would eliminate a housing, battery pack, a cable, and some circuit redundancy. It would also provide an upgrade path for relentless tweakers and op-amp rollers. That would be a hot feature at head-fi.


gerG

 

[JoeBorn]

Quote:

Originally Posted by gerG Digital out via toslink. I saw that you listed s/pdif, but not which format. A high grade internal dac sounds tempting, but what sort of output connectors are you considering? If it is the ubiquitous 1/8" mini plug I don't think that it is even worth the trouble. gerG

Starting with the above, you prefer toslink for digital out. It seems like most high end folks hate toslink, no?

Regarding the plug, what's wrong with the 1/8" and what do you suggest?

Also, I should probably clarify the positioning of the device since there I seem to have created some confusion. We are really targeting the high end of the portable MP3 player market, something that improves on the sound quality of what's out there now and has great software support (lossless codecs, multiple codecs, gapless playback, etc.). Its not a DAT replacement, but a high end MP3 that a user could chose over an iPod or whatever for more flexibility and SQ, but I guess it's not targeted at the super geek in terms of making big tradeoffs in size, portability, etc.

 

[JoeBorn]

Quote:

Originally Posted by Jazper ok I'm going to be frank here: I think you're barking up the wrong tree. First a high end portable needs to at least have some sort of analog output, not everyone carries around a portable dac to interface with toslink or SP/DIF. You don't need a dac if you're just outputting digital. Second a high quality recording/playback device needs to get power from somewhere. Power is a concern. Power is a huge concern for a portable device, a measly 35mA consumption will kill a 350mA battery in 10 hours. If you're planning a hard drive (with at least 100mA consumption) and a dac with at least 30mA, an adc with at least 30mA consumption a cpu with 50mA and other bits and pieces like recievers/transmitters for outputs that quickly adds up. How do you plan to fuel this thing? DAC chip wise (if you are going with a dac) I'd try and go with something that sounds as neutral as possible, my choice, something like a wolfson WM4780. BB and Crystal are laid back and solid state glary respectively. Or try and balance it, for instance if you go a bb dac, complement it with a crystal headphone driver or a IT tpa6120a2, or something similar. Clocking wise, (while I'm sure this has been done before) I'd suggest going with dual oscillators, and have a chip split the difference between them. High accuracy watches use thermal compensation to keep their high speed quartz in check, perhaps you could implement something similar. thoughts... read into them what you will.. I may join the irc channel sometime

I think that your point about doing too much is a good one. Again our market is really not the professional recording folks, it's just a high quality, open source audio player. It really just builds on our previous generation of audio players, we're essentially targeting the same market. Closest competition would still effectively be the iPod, iRiver, etc.

 

[JoeBorn]

Quote:

Originally Posted by gerG Hmmm, the more I think about it, the more I like the idea of a high end amp module that could be swapped out/upgraded. It would require an internal docking bay and standardized connector, but it would eliminate a housing, battery pack, a cable, and some circuit redundancy. It would also provide an upgrade path for relentless tweakers and op-amp rollers. That would be a hot feature at head-fi. gerG

Well, there have been elaborate discussions about a "universal bus" for the N3 and the conclusion has been USB (host and device) which would allow the connection of a great variety of peripherals includin what you are talking about above (at least on the hardware level). Software is another matter, but I feel we largely have that covered as well.

 

[gerG]

Quote:

Originally Posted by JoeBorn Starting with the above, you prefer toslink for digital out. It seems like most high end folks hate toslink, no? Regarding the plug, what's wrong with the 1/8" and what do you suggest? Also, I should probably clarify the positioning of the device since there I seem to have created some confusion. We are really targeting the high end of the portable MP3 player market, something that improves on the sound quality of what's out there now and has great software support (lossless codecs, multiple codecs, gapless playback, etc.). Its not a DAT replacement, but a high end MP3 that a user could chose over an iPod or whatever for more flexibility and SQ, but I guess it's not targeted at the super geek in terms of making big tradeoffs in size, portability, etc.

Personally I prefer optic cables to the coax electrical implementation. Usually it is an interference or ground loop issue, so probably not relevant here. My DACs use AES/EBU, so I have to build a cable to get from coax to xlr. I have read some hypothesis that coax is superior to optical, but I haven't seen any data that would ground that claim. I like the fact that an optic cable can be extremely compact and light-weight.

ok, now I understand the boundaries a bit better. Unfortunately the mini-plug is the default in the consumer market. It has to be there. Might as well combine it with the optical out (a la airport express) and save some space. My issue is that mini sockets are unreliable and inconsistent. I have heard the image shift while I was listening to the music, only to snap back when I rotated the mini-plug to re-set the contacts. My preferred connectors would be test equipment grade (microdot or similar) but would be too expensive just now. They may catch on some day, though.

I still like the amp module dock concept. It makes much of the above a secondary consideration.


gerG

 

[gerG]

Quote:

Originally Posted by JoeBorn Well, there have been elaborate discussions about a "universal bus" for the N3 and the conclusion has been USB (host and device) which would allow the connection of a great variety of peripherals includin what you are talking about above (at least on the hardware level). Software is another matter, but I feel we largely have that covered as well.

Actually I was not suggesting a digital module, although that would be groovy. I was thinking along the lines of a module that would connect to analog signal bus and power cell. The module would handle volume control, amplification, and headphone interface (a full 1/4" socket would make a hell of a statement). The thought of being able to choose my amp, and plug it straight into the player, would be a level of flexibility and integration which does not exist in the market today. No more interface cable to the amp, and no more extra box to juggle.


gerG