I am happy to see some interest being generated about the headphone amplifier I designed!
Let me start by answering a couple of your questions.
"Hey, I've heard some about this amp you will be releasing, do you have any information on it or a sample I could review?"
Project Woodwind is in the final stages of electrical design completion and verification. This means that the design has been built, tested and repeatable results (across 10 boards) have been verified. At this point we are looking to complete the mechanical design to finalize our product. We have also sent out some of our tested boards to a few reviewers (ClieOS being one of them) to get some feedback on the audio characteristics of the amplifier (so far the preliminary reviews have been excellent!).
Here are some of the measured performance numbers, specifications (measured on an Audio Precision Analyzer at an output level of 125mW, driving 32 ohms), and features:
SNR: -109.2 dB (A-Weighted) L&R
Dynamic Range: 109.4 dB Right, 109.6 dB Left (A-Weighted)
THD+N: 0.0023% (-93 dB) L&R
Freq Resp: +-0.14 dB 20 - 20000 Hz L&R
Max Output Power: 125 mW
Can drive headphones up to 1k ohms of impedance with up to 3Vrms
18+ hour battery life (850mAh lithium polymer battery)
Supports TRRS headphones allowing headphones with a microphone to operate while connected through the amplifier
Supports battery charging through mini usb port (500mA) and 5V wall adapter (1A)
Battery level and charging indicators
fixed gain level (volume was intended to be controlled on the device sourcing the audio), the sample boards have 6dB of gain (2x volume) which seems to be just right for android and apple phones
projected price of ~$85
Attached are several plots showing the results of our Audio Precision Analyzer testing results. Also, I would be more than happy to send out a unit for you to review. It would be the amplifier without the housing, but like most audiophiles, I'm sure you are mostly interested in the performance. Just a note on the performance specs. The numbers I listed above are tested at the maximum output power level, whereas the competition (Fiio to name one of the many companies) tests their products at lower output powers to improve their numbers and we still come out ahead!
"Any pictures or the priority you guys have this amp at?"
Attached is a picture of the amplifier without the housing along with a ruler to help you judge the size. We have several other projects in development right now but as of right now Project Woodwind is taking priority with us. I have been playing with the idea of selling a limited run of just the boards with the battery for people depending on the interest of an option like this (similar to how JDS Labs offers some of their products without the case). If this option goes forward we would be able to have boards shipping in ~ 1 month ($65 for amplifier board + battery) and 4-5 months for the amplifier with housing.
As we are trying to generate some interest, feel free to pass this information along if you would like.
Thanks for your time and interest!
Critical Point Engineering
Co-Founder and Lead Design Engineer