AMB's γ1 Miniature DAC Project

[sponge]

I had been thinking about putting together a "portable" headphone system to use in the consevatory in readiness for those warm evenings (Har Har!). This system was (hopefully) going to sound as good as my main system - Squeezebox Classic > TC-7520 (modified) > DIY M3 Headphone Amp > AKG K701 Cans.

Enter the γ1 (gamma 1 http://www.amb.org/audio/gamma1/ ) which I had read about a while back. It seemed to fit the bill - USB, Coax and Optical inputs, compact, USB or wallwart powered.

A quick check on the parts list - Looking good, should cost less the 100GBP complete.

So I went for it.

Well, I have just completed the build and the unit is bedding in (is that necessary?).

I was expecting reasonable performance, but this little DAC is seriously good IMHO - Well above my expectations, and then some!
And what a nice little project - Perfect for any DIY electronics fan.

If any of you guys are interested, I will take and post a few snaps of the DAC, and also my take on how the γ1 compares to the TC-7520.

Cheers - Ken

[leo]

Course we are interested Ken pics, opinions and comparisons are always welcome on here

[jon1]

I had been thinking about putting together a "portable" headphone system to use in the conservatory in readiness for those warm evenings (Har Har!). This system was (hopefully) going to sound as good as my main system - Squeezebox Classic > TC-7520 (modified) > DIY M3 Headphone Amp > AKG K701 Cans.

Enter the γ1 (gamma 1 http://www.amb.org/audio/gamma1/ ) which I had read about a while back. It seemed to fit the bill - USB, Coax and Optical inputs, compact, USB or wall wart powered.

A quick check on the parts list - Looking good, should cost less the 100GBP complete.

So I went for it.

Well, I have just completed the build and the unit is bedding in (is that necessary?).

I was expecting reasonable performance, but this little DAC is seriously good IMHO - Well above my expectations, and then some!
And what a nice little project - Perfect for any DIY electronics fan.

If any of you guys are interested, I will take and post a few snaps of the DAC, and also my take on how the γ1 compares to the TC-7520.

Cheers - Ken

You kept that one quite kensome pics please



jon

[sponge]

You kept that one quite kensome pics please



jon

I was always going to do a post about the γ1 - But when the bits started arriving, I got drawn into the build and, well, you know how it is ...

OK, I'll take the γ1 to bits and shoot some pics.

Ken

[jon1]

I was always going to do a post about the γ1 - But when the bits started arriving, I got drawn into the build and, well, you know how it is ...

OK, I'll take the γ1 to bits and shoot some pics.


Ken

Yes you get addicted ken must get it finished...




jon

[sponge]

Basically, the γ1 can be built several ways - I chose to build the "full" version because I needed USB and Optical inputs. Depending on what you require decides what components or boards are fitted. This also affects the front and rear panel design.
AMB sells pre-cut and etched panels for the full version, but they add $40 to the price - I chose to do my own... If you do this yourself, a vernier caliper is essential

Here is the finished γ1 front and rear:




The USB board can be configured to be a USB-to-S/PDIF and a USB-to-I²S converter if you need it to be, which would require the population of the rest of the board as you can see:



With the full version though, the USB board needs the DAC board:



And then the two boards plug together to sorm a DAC butty:



Here they are ready to be mated :



Once they are together and tested, they can be installed in the case



Front and rear panels are fitted and we are ready to play...

The γ1 is a nice match for AMB's Mini³ portable headphone amplifier which I built some time ago. This is how they look together:



Here is the rig in the conservatory being fed from a Sony CDP via the Optical out - The Mini³ is driving the K701's - Just needs the wallwart:




And here the kit is attached to the USB hub and using USB power - The selector switch is lit green meaning the γ1 is receiving data - This changes to red on data lost or errors. The Mini³ is driving Senn HD600's (out of shot):





There you have it

This little DAC sounds really nice and VERY close to the TC-7520 - Just how close I will report when I have done some comparison tests.
But for now I'll just enjoy a couple of these and some quality listening...

Ken

[sponge]

If I were making another γ1 I would probably use a black Hammond case rather than the silver, but I had the Mini³ in silver already and wanted a match. Well, nearly, as the Mini³ has black end panels, but you know what I mean

Oh, and BTW - It will be interesting to try the original 5V switcher with the γ1 that came with my Squeezebox - I didn't think about it, and bought another 5V wallwart (a linear) which is about 4 times the size and weighs several times the γ1!

Ken

[jon1]

Nice one ken..I see that sex had to creep in on your postPcbs mating..BTW nice pics



jon

[sponge]

Nice one ken..I see that sex had to creep in on your postPcbs mating..BTW nice pics



jon

Thanks, I do try to keep it clean Jon - It's just the interlocking procedure that seems to send me off on one

[jon1]

Thanks, I do try to keep it clean Jon - It's just the interlocking procedure that seems to send me off on one

Ken you do not know what members are doing behind the scenes..Like your self quietly building dacs..now enjoy it




jon