DACport development blog

First Production Underway

We have played enough with DACport and now it’s your turn.  The product is sufficiently stable and there are no known bugs at this point,  so now it’s just turning the production crank and making DACports available to you.

Having listend to various material through DACport over a variety of headphones we are convinced that the sound quality is second to none! The performance is simply outstanding! Familiar recordings really come to life in a new way.  I promise that once you listen to DACport you will never want to return to the on-board sound card again. The difference in detail and clarity is just night and day!

Amazing Specs, Amazing Price

DACport gives you an Ultra Low-noise, portable Class-A headphone amp, over 40 kHz audio bandwidth, 100dB THD, and true USB plug and play. No batteries are required. Most importantly, you can listen to true 24/96 HD content without the need to install any custom drivers – all these benefits are courtesy of CEntrance exlusive USB technology, previously licensed to Benchmark Media, Lavry, Belcanto, Empirical Audio, PS Audio and many others. With CEntrance, you can’t go wrong!

All this quality and painstaking attention to detail will very soon be available to you, dear reader. Today I’m happy to announce the price.  We think we established a very fair price for DACport at $500 USD. No other portable product comes even close. DACport is a true first, a genuine CEntrance Innovation. In fact, we are so convinced that you will absolutely love the product that we are offering a 30 day money back guarantee, too!

Early Bird Discount

As promised, those of you who have submitted you email here will have a chance to order he product with a 10% discount, at a low introductory price of only $450. There is still time to get the early bird discount through the end of the year, but on January 01st the price goes up, so hurry!

We are building the initial quantity of units this month and plan to have them available around December 22nd, in time for the Holidays. We will throw in free overnight shipping, too (US only).  In a couple of days we will open up the pre-ordering opportunity – initially to those, who have submitted their emails here. I will make a special announcement about that soon.

Everyone wants to get immersed in the experience of listening go high-quality music. CEntrance now has the answer to that need. DACport is our true pride and joy, a product of years of reasearch and development. We are very excited that it is finally becoming a reality!

Some people have asked to see a picture of the finished product. Here is a photo of a pre-production sample.  The final product will look almost the same, except slightly lighter gray. Click the image for a larger size.

We are still deciding on the final packaging, but most likely we will start out with the same box with a transparent window, which we currently use for our other products.

Feel free to ask questions in the comments section. And yes – we will be announcing the price this week.

I don’t own a TV, but I still saw how much time was devoted recently to promoting “Our Choice”, the new book by Al Gore… Global warming is a serious concern, and here at CEntrance, we support the green cause. We want our customers to save energy and that’s why we pay special attention to power issues. Let’s talk about DACport’s power consumption.

DACport does not require any batteries or chargers. It takes its power entirely from the USB jack on your desktop, laptop or netbook computer. And DACport is very smart about the power current, to save power and make that battery last longer.

Let’s start by saying that when you first plug it in, DACport starts in “low power” mode and takes only about 60 mA of current on the 5V supply. In this startup mode it performs initial USB handshaking and then requests additional power. That’s the “polite way” of establishing a USB communication, according to the USB standard, and we follow the standard to the “T”. This negotiation is instantaneous – it takes a fraction of a second and ensures proper configuration and no data loss.

Having performed initial USB handshaking, DACport requests full power, which is granted by the OS. That starts up the main switch-mode power supply that ramps up the 5V to +/-9V for the audio circuitry, +3.3V for the digital circuitry and clean +5V for the converter circuitry. In total, DACport has 5 (five) separate internal power supplies! That’s how we ensure that clean power is supplied to all circuitry to maintain the ultra-low distortion.

When designing the DACport we took a close look at the amount of power available from the USB jack. Typically it’s 5V x 500 mA, which results in 2.5 Watts of power. Not all of it is available for Audio however – in fact about 1 W is taken up by the digital and converter circuitry, so 1.5 Watts is the real Audio output power.  In most cases, that’s plenty, since even the low-impedance headphones are very loud at 500 mW.  DACport makes 1.5W available for audio.

When no music is playing, DACport goes into low-power mode to save the battery. But when you press “Play” it immediately springs into action and turns on full power. This is the benefit of using switchmode power supplies – they react in microseconds and allow to efficiently manage power consumption on the fly.

Because DACport’s headphone amplifier is Class A, it takes a steady amount of current during normal operation, but there is some variation depending on the impedance of the connected heapdhones and loudness of your music.  DACport normally draws less than 400mA from the USB port, giving you enough power and ensuring class-compliace by a healthy margin. DACport is very careful in how it manages power – it takes only what it needs, when it needs it, which saves the battery on the computer and lets you enjoy your music for longer on the go!

Today is the day when Americans are traditionally getting together to give
thanks. This country has come a long way since 1621 when the first pilgrims survived the tough winter, which gave birth to the Thanksgiving holiday…

Today we thank the people who have supported us over the years. Without you we will not have a reason to move forward. We exist to bring new products to life and make living better for our customers. DACport is awaiting new chassis and PCBs. Next week we are planning to make some exciting announcements, so stay tuned…

This week I will be reporting from Los Angeles. CEntrance maintains a busy consulting practice and that means frequent travel for your humble reporter. Today LA is cold and the usual feeling of exhilaration one experiences coming from Chicago is gone. From one cold city to another — there is no fun in that! But… the strawberries on the west coast are simply delicious! Lush, firm, juicy and sweet. All organically grown, too. Well, travel must have some perks.

Meantime, DACport development continues at full speed as our engineering team keeps working back home. New samples of the chassis should be coming in next week and work continues on redesigning the PCB: We are fitting in a better crystal and getting rid of a couple of blue wires to improve manufacturability. More on this soon.

Well, we can’t contain our excitement. The supplier sent us pictures of the new cylindrical chassis and low and behold – our prayers have been answered – instead of 2 holes on the top, we now have 1, which is the correct number!

We are now much closer to the day when everything in the chassis is entirely per spec. However that day is not today, since laser engraving needs a slight change – capitalization of DAC in DACport. Fortunately, that’s a minor issue, compared to what we’ve gone through, so we are looking forward to the chassis saga to be over very soon. You are tired of hearing about it, no doubt, and so are we…

Take a look at how close the actual part is to our 3D rendering…

An old boss once told me that you could never have enough prototypes and those words still ring true. We just built our first pre-production run of 10 units, to prove out the manufacturability of the design. Clearly that’s not enough!

We received good customer feedback about the product and we want to ship a decent quantity of DACports. In order to build the product in volume we need to make sure that the design is manufacturable.

New products often ship with tiny hand-soldered wires on the PCB, the result of hand-made rework, to fix last minute issues. This raises the cost of assembly and decreases product reliability. At CEntrance we don’t like manual rework and typically ensure that the product can be built entirely automatically. Sometimes this requires extra PCB turns, to get everything “just right” but we feel this is worth it in the long run.

Our 10 prototypes are going to the media outlets for reviews. The next run of 100 pcs is scheduled for the end of November. The goal is to make 100 units available for sale by Christmas. You can reserve your unit by adding your email to the list here. Soon, we will start taking pre-orders for the product. The first production run of 100 units is not fully spoken for yet, but the que is filling up fast.

Our customers will be happy – DACport will be more robust in the result of a recent spur of R&D activity.

Stability of digital devices is key and your humble reporter got concerned last week when we discovered a bug that caused the 24.576 MHz crystal to suddenly quit oscillating when the ambient temperature increased. We mentioned previously that a burn-in test allowed us to discover this failure.

Simply replacing the part with a cross from another manufacturer just didn’t seem like a robust solution… At CEntrance we believe in “No stones unturned” engineering discipline, so we dove head-in in to the physics of ceramic oscillators, to determine the factors that could cause oscillator failure.

Our mil-spec, 10ppm crystal will provide its incredible frequency stability as long as it’s driven by an appropriate oscillator circuit. The more precise the part, the more demanding it is on the operating environment. The crucial parameter in this case was “oscillator drive”, which is a function of the chip that drives the crystal. The chip provided enough power, but with little safety margin. As temperature increased, things got out of whack and oscillation became erratic – a sure sign of things being on the edge.

We won’t name the reputable vendor that somehow omitted this important parameter from the datasheet… We ended up having to contact the manufacturer to get the low down on the internals of the circuit. Note to self: Even reputable vendors can throw a curve your way…

And you think CEntrance of anyone should know — CEntrance is the official 3-rd party design firm for Texas Instruments, Analog Devices and many other semiconductor vendors. Do things always go smoothly? No, they don’t and this blog gives you a glimpse into the daily life of the developers. We certainly don’t know everything, but we know how to get information and we learn quickly… I’m just glad that we caught this bug before DACport went to production! Testing, testing and more testing…

Light-hearted Friday humor: Look up synonyms for the word “information” in MS Word and here is what you get…

The Internet is finally up and boy is this a relief! So many things are now possible… like communicating with our customers, for one example.

Case in point – the DACport Information Universe is growing and there is more information to read on the product.

Even though the product is not shipping yet, we had some customer requests and so we have enabled the DACport forum. Now you can read the FAQ, ask questions and interact with us and other people. Once we start shipping, we expect that folks will be sharing experiences about using product, its audio quality, design, build, etc.

We don’t sensor the posts – if you have a negative experience, we don’t delete it like some others, just to make the fourm look good. Instead, we answer to the best of our ability and provide the solution for your problem. So don’t be shy, communicate away!

The DACport user forum, still in its infancy may be accessed right here:

http://www.centrance.com/forum/viewforum.php?f=22