Open-source USB interface: Audio Widget

[borges]

Hi Zelter,

please try the SDRwidget mailing list. You're more likely to get help there. Oh, and if you end up with a short how to, feel free to add it to the Wiki :-)

Borge

[alexlee188]

Hi Zelter,

Let us know:

1. What hardware - sdr-widget or AB-1 or USB9023
2. What Windows - XP or Win7, 32 or 64
3. What firmware - unified firmware for sdr-widget? Or for audio-widget?

When u plug the widget in for the first time, does windows ask u to install a driver?

Alex

[borges]

Hi Zelter,

if you are struggling with Win7, have a look here:
Win7_64_setup - sdr-widget - Tips and tricks to make things work on Win7 / 64 - Audio and Control Interface for Amateur Radio SDR and Audiophile USB-DAC - Google Project Hosting

There is a difference between SDR-widget (radio amateur functionality) and audio-widget (audio only, currently just playback). For the former I recommend the mailing list. Sorry I was a bit quick there.

Børge

[zelter]

Hello Alex,


1. What hardware - sdr-widget or AB-1 or USB9023 I use AB1
2. What Windows - XP or Win7, 32 or 64 WIN XP 32
3. What firmware - unified firmware for sdr-widget? Or for audio-widget? unified firmware

When u plug the widget in for the first time, does windows ask u to install a driver? Yes


Zelter

[alexlee188]

Try "have disk" and lead win XP to the drivers:

SDRWDGT....

If not successful try

AUDWDGT....

Note u need to unzip the driver zip file into a folder first.

Alex

[UnixMan]

Food for though:

ESS Sabre Reference DAC (8-channel)

Wizard High-End Audio Blog: More pictures of Accuphase DC-901

...something like this would be nice for a future version!

[alexlee188]

Hi UnixMan,

It depends on what you want/need and how deep is your pocket :-)

I am using my audio-widget AB-1 and USB9023 on a daily basis. I'm now travelling and with my laptop, USB9023 and Beyerdynamic DT-990 headphones, I'm having a great time listening to music (88.2, 96 and 192khz 24 bit), and watching movies. You can buy an AB-1 for about US$160 and the USB9023 for under US$100. It is USB powered and you can slip either one into the laptop case. You should listen to one first and you might be surprised at how good it already is.

If what you want/need is an 8-channel ES9018 based DAC, then help to design one :-)

Our Atmel based USB-I2S module is limited to stereo. George is designing stereo USB-DAC boards using ES9012, PCM1794A and/or Wolfson DAC's. These will probably make it to the ALPHA stage in the near future, after the present run of 50 revised USB9023 kits.

A multi-channel USB interface is in the drawing board and it will involve either FPGA or chips specifically designed for multi-channel USB from C-Media and others. This will take longer to materialize.

The whole rationale of our project is to provide open source firmware and open source schematics, to enable other experimenters to improve and innovate :-)

Alex

[UnixMan]

Originally Posted by alexlee188

It depends on what you want/need and how deep is your pocket :-)

unfortunately, there are rather conflicting issues about that. Were my pocket deep enough, likely I would have bought the Accuphase and lived happy. Unfortunately, my pocket can't afford that much.

(it cost "only" 1,115,000 Japanese Yen =~ $15,000 USD).

Originally Posted by alexlee188

I am using my audio-widget AB-1 and USB9023 on a daily basis. I'm now travelling and with my laptop, USB9023 and Beyerdynamic DT-990 headphones,

I'm not interested at all in portable operation. And simply can't stand any ear/headphones, ever. Pretty different goals...

Originally Posted by alexlee188

It is USB powered

that's the worst thing you can do about suond quality!

Of course it's a nice handy feature for a portable device (such as your nice small single board version, which is really great for that use), but it is absolutely a no-go for anything which has any ambition to be really "top quality" sound-wise.

Please have an in- depth look to the "ART - Legato". This nice product, connected to a TP Buffalo II (ES9018 used in two channel mode for best quality), does really makes wonders!

(I was about to write literally "miracles": what it can do is simply unbelievable if you don't listen to it yourself through an adequately high-quality system!)

Even with CD standard source material (which is the only thing it does support) it sounds WAY better than any other s/pdif source we've ever tried.

Compared e.g. with the popular " http://www.m2tech.biz/hiface.html " (which use a non-standard USB2 asynchronous connection) there is simply no game. The "Legato" is on a league on its own. It sounds way better than the hiFace not only when playing the same (44/16) source material, but even when using HD source material! (which had to be downsampled with sox to be used with the Legato)

Modifiying the hiFace by removing it's internal switching PSU and providing external (linear and clean) supplies does improve it, yet even with such (hard) modifications it still does not even approach the sound quality of the Legato.

So, what I'd like to see from the "audio-widget" project would be something which have the quality of the Legato but using UAC2, thus supporting also HD material. "Directly" connected to a DAC of the highest possible sound quality.

A truly "hi-end" product, that can be built at a reasonable price.

Of course, the concept of what a "reasonable price" is may be pretty different among people. To me (and I guess for most other audiophiles, too), for a "top-quality" USB DAC complete with PSUs and box a part cost which is an order of magnitude higher than that of the current audio-widgets (that is around 1-2K US$) would be more than reasonable... it would be even cheap!

(after all, that's still more than an order of magnitude less than a good Accuphase ).

Originally Posted by alexlee188

If what you want/need is an 8-channel ES9018 based DAC, then help to design one :-)

uh? no-no-no-no! Perhaps you misunderstood my point.

I do not need (nor want) multi-channel! I want stereo! Only 2 channels. But top quality.

The commercial product I was talkin' about in the previous post is NOT a multichannel thingy. It's just an hi-end, high quality stereo DAC, (only 2 channels). Which uses two ES9018 chips per channel, that is 16 DAC modules for one channel!

(in other words, it uses a total of four ES9018 just for "simple" stereo output!)

Originally Posted by alexlee188

The whole rationale of our project is to provide open source firmware and open source schematics, to enable other experimenters to improve and innovate :-)

sure. And that's the great thing about it!

[alexlee188]

Hi UnixMan,

In that case you are talking about an AB-2 :-)

Well we are hoping that someone from this forum will take our USB-I2S module and design an AB-2 for it, having seen (and preferably heard) the AB-1 or AB-1.1.

Our team of designers (speaking more for myself, specifically) are not experts in top end analog designs. So we welcome designers to come up with kits to mate with the USB-I2S module, with top end features:

1. PSU with independent, isolated, low noise, low impedence etc.
2. DAC with dual-mono, quad-mono, or more extreme designs
3. super duper IV stage, eg extremist-DAC circuitry
4. buffer/line-driver/headphone driver stage, maybe tube based.

There is a tradeoff between feature/quality and cost. Maybe the right balance will appeal to more audiophiles and if your can sell 50-100 units, the cost of design and parts will be lower.

Our present focus is to get AB1.1 and USB9023 (both are available for order now) to the hands of more audiophile experimenters for their reviews and comments. I have also mentioned that George is designing single board USBDAC's similar to USB9023, using ES9012, PCM1794A or Wolson DAC's. Thus we are targeting the under $200 diyaudio segment.

We will leave the > $1000 segment to more capable hands :-)

Alex

[UnixMan]

Originally Posted by alexlee188

In that case you are talking about an AB-2 :-)

yes. But not only.

Also the digital board may need some improvements. That's why I mentioned the Legato (which is just an USB to s/pdif UAC1 async interface, see here: http://www.audiofaidate.org/forum/viewtopic.php?t=8408 ).

Before hearing that one, I was (naively...) thinking that with an async connection and a good local clock one could basically forget about the digital domain and all of its problems. As I discovered the hard way, it's definitely not that simple. Even with an async link, there is still a long way to go. Have a look at the interesting measurements made by my friend and colleague George "Joseph K":

DIYHiFi.org • View topic - Some jitter analysis - and beating of a dead horse..

To obtain such amazing results, the Legato uses a lot of care in power supplies, clock, signal routing, layout, etc. Most (if not all) of the tricks used there have been previously documented by Joko (the Legato designer) on either this or that other forum, and perhaps similar strategies and care may/should be applied to the audio widget as well.

Originally Posted by alexlee188

1. PSU with independent, isolated, low noise, low impedence etc.

I definitely second your points.

BTW: for what regards PSUs, have a look at "Salas shunt reg." and/or Joko designs on this forum.