The Objective2 (O2) Headphone Amp DIY Project

[Turbon]

Actually I have no idea of who that might be... ;-)

Now, I hope this OT didn't bother you to much RS.

[RocketScientist]

Originally Posted by qusp

ii have the correct hiface OEM usb-i2s module to drop on it already, so its an easy simple solution at less than 100 for a compact hires 2 channel USB dac

Is that module generally available in single piece quantities to DIYers? What USB chip is it based on? Does it provide MCLK for the DAC? And does it require a proprietary driver or is it fully UAC1 compliant?

[ethanolson]

Is it the M2Tech hiface? I think that has its own drivers instead of UAC and I think they no longer supply the modules. Is that right?

[Turbon]

M2Tech Hiface - "Internal very low jitter oscillators and proprietary drivers allow for playing 192kHz/24bits audio files that feature the best signal quality."

M2Tech Hiface EVO - "Asynchronous operation up to 192kHz is used in conjunction with proprietary drivers which allow for Kernel Streaming, Direct Sound and WASAPI operation (the latter under Windows vista and 7)."

[qusp]

Turbon is correct, its an OEM module based on tyhe same chipset and basic design as the Hiface. A while back a GB on here for it was stopped in its tracks because the datasheet was made public and they were made aware of it, so they never supplied it to the general public. i went ahead bought them legit as an industry professional, but i think you would struggle to get them to come to the party with licensing and the lack of a UAC2 driver is probably another deal breaker for you. it does expose all the power supplies, i2c and control pins as well as i2s.

so because i have them already the 98 dollar ES9023 dac deal is a screaming winner for this dac/amp i'm making for my friend.

[ethanolson]

ES9023? Interesting. I'd love an ES9012 DAC running UAC2 (& UAC1) feeding an ODA or "The Wire" tuned specifically for my AKG's power range.

[qusp]

Originally Posted by ethanolson

ES9023? Interesting. I'd love an ES9012 DAC running UAC2 (& UAC1) feeding an ODA or "The Wire" tuned specifically for my AKG's power range.

yes es9023 for my mate; me i'm running UAC2->multichannel i2s-> AKD12 into NTD1 IV (with the bal-SE wire and soon bal-bal wire) but i'm also running a second akd12 and these 4 channels with 4 matching power amps using a digital crossover power my soon to be finished 2 way speakers

no need for tuning for AKG, unity gain is perfect for ~60ohms but that assumes you are running regular AKG. i cant remember if you had 240's or k1000 or something nuts =)

kids run away before the DIY bug gets you!!

[ethanolson]

Wow... your setup is pretty much my persuit. Anyway, I'm rolling with the K 171 Mk II headphones, so unity is probably fine because a gain of ~1.6 would be my max from 2V feed and I would want to use more than the first 1/3 of the volume pot.

It's amazing how much better they sound amped... and I'm a quiet listener.

[ethanolson]

@qusp,

Why does everyone have I/V stages for their ESS DACs? Don't they have a voltage output option? TPA does it. AckoDAC does it. And others, as well. Does current mode sound better even with the I/V circuit?

[RocketScientist]

@ethanolson, the short answer to that question is most DIYers design "blind" without proper test equipment and using only heavily biased sighted listening as their guide. They very often think they hear things that don't really exist as has been demonstrated countless times in blind listening tests. if you throw a bed sheet over the equipment, without changing anything else, the benefits they think they hear magically disappear. So it's easy to see how they think adding an op amp stage to a DAC chip improves the sound when in reality it might make the performance a bit worse.