AMB Gamma 2 DAC (or how NWAVGUY fooled us all)

Did you ever get a gamma3 in house to try?

 

Don't forget this neat little trick the Odac presents when stimulated with a 0 dBFS square wave.

Here is the overview response:


The area circled in green above will be zoomed below.


Isn't that special?
Digital filter goes bonkers ratcheting substantially.
Don't think music signal will present nearly square wave rise or fall times?
Have a look at a timbale hit from a recording below:

Let's zoom a selection from the beginning of the timbale hit.

this is the timbale beginning waveform which will be sent to the odac

Here is what the odac does with the timable hit data it received in the digital data stream.

Zooming in we see the odac making rather nasty modifications to the timbale hit.

Isn' that lovely. Rail to rail ratcheting. I keep the odac in the lab as one of the negative examples of DAC design.

 

Thanks for doing this @purr1n

It’s very cool to see objectivist bullshit debunked by objective measurements.

and agreed about Ti Kan of AMB. I’ve met him at meets long ago and he’s the exact opposite of newavdeuce. Kind, humble, intelligent. Just goes to show how good marketing sways people and how often the honest, no BS people get overlooked because they don’t play the game. It’s a pattern that’s sadly repeated all across the world in all of society.

Similar factors allowed Kevin Gilmore to convince people that Alex Cavalli’s amps were shit. Alex just didn’t play the game and Kevin Gilmore played it very well.

Just curious, did you use USB or SPDIF? I’m curious how good the USB is on this.

 

If anyone is interested in hearing this I’ve got a loaner tour setup when Purr1n in done with it.

you can sign up here

 

I've been using my gamma 2 for over 10 years now and it's fended off my "upgraditis". Outside of meets, the last direct in-home comparison I've done with this DAC is with the first-gen Schiit Bifrost which I had a hard time hearing a difference with. It was a no-brainer keeping the gamma 2 due a combination of its size, performance and portability.

It's nice to see it getting some technical attention especially in the context of the whole Nwavguy saga. I admit to being one of the many who bought into his hardware, but ultimately found them lacking in overall sound quality (especially the O2 amp). Thanks for doing this!

 

Gamma2 has been my daily DAC at work for over 10 years also. Its at the front of a 2-Chan setup that is all AV123 stuff. X-Omni's and X-Sub. It's a perfect work setup and would probably be great for anyone getting into affordable 2-Chan.

The Gamma 2 sound seems to be what I am familiar with growing up and nothing about it really offends me in any way.

 

It was AMB's designs that convinced me to drop the whole objectivism thing, years ago. I had an ODAC/O2 driving some HD650 when I scored a good trade on a gamma2... around the same time, ojneg lent me his homemade CKK amp. I still peek at AMB designs from time to time, the documentation is truly excellent in how thorough it is.

I don't see myself ever selling my gamma2. The thing is relatively portable, sounds very respectable, and has features like a swiss army knife. It's great to have around in a pinch. It's also really interesting to see how bad the ODAC measurements look in comparison.

 

Ti Kan is one of those DIY guys that's universally loved no matter which forum I've been on*. For NWAVGuy to pick beef with him is kind of shit. I can't tell you how many people just assume an active ground is trash engineering just because NWAvGuy said it.

*Have no idea about ASR

 

I own and like this DAC but don't have a clue about engineering. I remember the ODAC sounded worse.

This will probably read like trolling, but I swear it's not intended to be. It's just ignorance:

My friends record sound for film and music (from podcasts to theatrical feature films) and generally the interfaces they use are relatively inexpensive. I think the Sound Devices 744T series is $1000 used and good enough for feature films.

How do these interfaces compare with dedicated amps and DACs for headphone listening? I figure the designs have to be okay if they're made for professional high end recording and playback. The Apogee Duet 2 sounded good to me with HD650s. (Better than ODAC, at least.) The Sound Devices interfaces I have sound great to me.

But they are very loud and bassy. Strange choice given they're designed for monitoring mixes.

Anyway where do these fit in? The Mix Pre D I own sounds great to me but there's a lot of bass and a lot of volume. I've never tried a high end DAC and have no frame of reference.

 

I remember him from HF, he was super nice guy.

 

During some level-matched DAC AB testing (for which I made a dedicated switching box with individual volume pots, basically a dual-input passive preamp), I discovered that the ODAC has seriously nasty clipping problem when a Mac feeds it a signal at full system volume. The audible clipping disappeared at about 50% system volume. Not sure if the problem occurs with other source systems. It wasn’t at all subtle, it was a huge scratching noise when the music hit certain notes. Only the ODAC did this in my tests (which included the gen1 multibit Gungnir, a Soekris dac1541, an Emotiva AKM unit, and an RME ADI2).

So here’s a question. Is my ODAC defective? Or is there something in those measurements which might explain what I heard?

For reference, the problem is audible on the track Salavatore by Lana del Rey, at every one of the low-frequency hits (like at 0:10 but repeating often through the entire intro until 0:42).

 

To give the ODAC credit, while it was shrouded in marketing through controversy, I believe at the time the Gamma 2 was something like $200-300 in parts (does anyone remember the exact figure?) while the ODAC was $99 for an assembled PCB (just add an enclosure). In that sense and the attention it brought to the hobby from more casual listeners I think the ODAC was a success and justifies its existence.

 

There is no giving the ODAC or NWAVDEUCE any credit. He was a piece of shit. And no, nothing justifies its existence not even bringing people into the hobby by way of lies, mistruths and phony science, leaving them with nothing but misunderstandings and brains full of bullshit for years. He started a whole movement of ignorance that remains to this day (ASR for example). The worst kind of propaganda is the kind that tries to back itself up with pseudo science and mistruths.

And I don’t particularly like you comparing the costs using a finished unit vs the cost of a board. Not the same. If the board cost 100$ then a finished ODAC cost quite a bit more.