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The Audio-gd Compass (Was: Designing an alternative to the Zero DAC/amp)

post #1 of 7724
Thread Starter 
Please check these two links and the FAQ first:

Audio-gd's web page for the Compass here.


and:

My main Compass FAQ I've written up and posted here.

==============

Shotgun FAQ: (Updated April 13)

What's the current status?
The final version has begun shipping.

How does it compare to other DACs and amps?
Please see the list of reviews in the FAQ.

What are people's impressions of it? I don't want to read through the whole thread to find out.
The impressions of the final unit start from this post on page 277 (if you're viewing with 15 posts per page). They are also listed in the FAQ.

What is the HDAM/OPA?
Long story. It's an amplification circuit for the DAC section. Audio-gd has three designs, the Earth, Sun and Moon. Each have a slightly different "voice", with the Earth being the closest to neutral. Switching them allows you to tweak the sound slightly.

Which HDAM/OPA is best for me?
You can read majkel's review of them here, which should give you some idea. Most people also buy the Moon, or Moon and Sun. The nice thing is, when you get bored, you can switch them around and enjoy something different for a while. Their sound changes over the first 350 hours of use (as they burn in) too.

Do I need to do any soldering to change the OPA/HDAM?
No. You only need a phillips screwdriver for the ground wire. The HDAM/OPA itself goes in a socket.

Will it drive my headphones ok?
It works fine with low impedance Denons and high impedance Sennheisers with no problems, so it should be fine with anything currently on the market. A gain switch will be added to make it easy to adapt to different headphones.

Can I order one now?
Yes. See the payment link on Audio-gd's site for Paypal info. As they are being made in batches, and because they are tested and burned in for 100 hours first, you may have to wait a couple of weeks to receive a unit. Don't forget to specify the voltage you require (110 or 220) when ordering.

Should I order the Audio-gd power cable as well?
That's up to you. I thought it made a good improvement. This is the first 'audiophile' power cable I've ever used, so don't take my word for it.

Please see the FAQ for more info.

==============

The following is the original version of this post:

With some of the recent concerns that have come up regarding the popular Zero DAC/amp, notably quality and getting the unit fixed if it is faulty, I asked the owner of Audio-gd, who designed and sells the HDAM opamps, if he was interested in designing a Zero alternative with similar features.

The logic is simple: It seems many people want a unit to get them started in Head-fi without a huge outlay. Since this often means something Chinese-made, there's some concern about quality and customer service, with units sometimes arriving on the other side of the world faulty or dead. What we've seen so far from Audio-gd is that they demonstrated both an interest in making good quality gear and providing good customer service.

We now have a chance to have this thing designed the way we'd want it if we were after a basic but decent DAC and head/pre-amp. So far, we've got a list of basic specs of the design:
  • Lightweight case, to save on weight and shipping costs. This because Audio-gd gear is boxed in quite solid, hand-shaped aluminium and is heavy.
  • Separate DAC and head/pre-amp boards, easily removable.
  • Surface-mount jacks (instead of jacks connected with wires), again for easy removal of components so they can be upgraded or replaced easily.
  • Coax, optical and USB input. The Zero is lacking the latter.
  • RCA out. XLR was suggested but is not necessary.
  • 1x or 2x RCA pre-input, so just the head/pre-amp can be used, with the DAC bypassed.
  • Alps volume pot. No cheap rubbish as seen in the stock Zero.
  • 110-240V switch-able power supply.
  • All high-quality components (Dale resistors, Fever caps, etc.)
  • All discrete transistors, no opamps!
  • The headamp should be able to drive low and high impedance HPs adequately, also notably sounding good with such headphones as Grado SR60s and Denon D2000s, as well as the usual Sennheiser HD650s.

What do people think of the idea? The goal is something that sells for around US$200-250, maybe depending on specs. There is the possibility of different versions of the unit, with, say, a better headphone amp or somesuch.

Gear mentioned in this thread:

post #2 of 7724
The most obvious opton is a DAC only version. Many zero users don't use the h/a at all, so this would be an option to get a decent DAC without the overhead of a h/a.
post #3 of 7724
Thread Starter 
BigTony: That's a good point. There could easily be an option to order one without the head/pre-amp board. They do have the $245/265 DAC-100 though.
post #4 of 7724
Two DAC boards, one per channel using a high end DAC chip on each board.

Each DAC board has it's own power supply.

No need for an amp section or Alps control.

USB interface chip can output at least 96kHz frequency using I2S connection to DAC boards.

Switches to selection how much upsampling is applied by each DAC board with lights showing the upsampling selected.

Selector for input type, optical, RCA or USB.
post #5 of 7724
Quote:
Originally Posted by slwiser View Post
Two DAC boards, one per channel using a high end DAC chip on each board.

Each DAC board has it's own power supply.

No need for an amp section or Alps control.

USB interface chip can output at least 96kHz frequency using I2S connection to DAC boards.

Switches to selection how much upsampling is applied by each DAC board with lights showing the upsampling selected.

Selector for input type, optical, RCA or USB.

yes all of the above plus XLR outs.

Thanks
Frank
post #6 of 7724
Currawong, Any time frame estimate you can give us for the dac(/amp) to go into production? I know this is still the early stages but I would be interested in this for my next purchase.

As for suggestions i don't really have anything to offer since i'm still officially a noob but it would be good to see the amp sell in the lower 200s rather than be closer to 250 since that would make it more of a entry level option.
post #7 of 7724
An interesting development I must say.
Certainly looking forward to the results.
I am looking to get a decent affordable external DAC in the near future.
As you mentioned, the Zero seems to have some quality issues judging from the feedback posted on here recently.
post #8 of 7724
Thread Starter 
slwiser: CDתÅÌ/DAC

I believe Troy has the DAC-8 if you want to know how good it is.

Crikey: Kingwa reckoned he'd need 2 months, so we're talking January or Feb I'm guessing. He thought he could create different options for different prices. He's enthusiastic to keep the price down, but I might suggest he do "sale to benefit head-fi" sponsorship, so that everyone benefits.
post #9 of 7724
Great news! Definitely looking towards this amp now. Hopefully i can get it cheaper when I source it locally in china
post #10 of 7724
Yes I would consider buying a good DAC if:

- Less than 500$
- No need for a headphone amp section
- USB, Toslink and SPDIF inputs
- Has buttons in front to switch between deifferent sources.
post #11 of 7724
I'd love a DAC-only option as well, but I'd want a switch between the different inputs (as in, a clicky knob thing) instead of buttons. My biggest pet peeve with the Zero is a usability one, it's annoying having to switch to Coaxial everytime I turn on the unit.
post #12 of 7724
Just a quick question: How much different is their DAC-100 from a modded Zero's DAC?
post #13 of 7724
Quote:
Originally Posted by smuh View Post
Just a quick question: How much different is their DAC-100 from a modded Zero's DAC?
I hope to get the DAC100 for audition by next week, and to compare it with the Franken mod. however, zero with franken mod is still much cheaper than the DAC100.
post #14 of 7724
Quote:
Originally Posted by smuh View Post
Just a quick question: How much different is their DAC-100 from a modded Zero's DAC?
I want to know that too.

As for the ZERO Franken mod, you need to have soldering skills and all the parts to do it. I think some of us like me don't have the soldering skills and the equipment and parts to do that kind of modding.
post #15 of 7724
Is a frankenzero really that much cheaper? once you buy HDAM and caps? The DAC100 is only 265 /w an HDAM in it.
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