Gamma-2 (γ2) DAC Thread - Page 10

Man, this is exciting. Put me on the list for pre-production boards, if you make a revision or get another batch. This would be a fun build and looks pretty potent.

Hm, with a single +5V power supply (and with the subsequent CMOS opamps) ... And with small power supply capacitance too ...

Dude, these two posts don't bring any useful info to the discussion taking place in this thread.

If you wish to participate in the thread (and in any other thread FWIW), please do it in a polite and proper manner, which means in this case stating why you think people shouldn't use the OPA2365 and if possible posting or mentioning why.
In general, it means supporting your posts and point of view with actual information based on your experience and knowledge (and since you are new around here, sharing your previous experience on the subject would be appropriate) instead of putting a rolleyes smiley, which is saying the least, quite rude...

Your second post is even worse, as you just mention two of the design characteristics of the project without expressing any kind of opinion... the tone in your posts is quite ironic which isn't much appreciated around here (just letting you know, since you're quite new here).

AMB is a very well respected member among this comunity which has designed (or participated in the design process) quite a few proven DIY projects and MisterX is also a very well respected member of head-fi, participating in many projects as well, so coming here and just trolling around isn't appreciated and certainly not needed.

Thank you,

Manuel Santos

Said what I was thinking!

Sorry if I was too explicit in saying what I thought or knew.

From my point of view, learning what I can from these forums, your "..."
doesn't tell me anything and does not help me to form an opinion. I want to know why you supposedly think these are bad things. All I see of your posts is a lot of part numbers and things like crisp or warm or pop.

Eh??

Let's just get back and stay on topic can we?

Indeed ^^

I just put in my and one other prototyper's order with Ti~
The gamma2 was going to be a "cheap" distraction untill the b24 decided to tag along for the ride LOL

OH WOW. Talk about exponentially increasing your wallet-damage.

Haha yeah well... I'm in holiday mode so my wallet knows no bounds.
Well, at least till it falls over and curls up into a limp ball... oh dear.

If you're getting this sort of problem, you may need to check your supply (including bypass) as well as your soldering throughout the signal path. I haven't had this problem except when I used it in an old breadboard that I later discovered had a loose contact and was, regardless, a less than optimal environment for the chip (although I did later get it to work).

I've been using this chip for a couple years now, and have used the it in several applications, both in single and dual supply. While it can be a bit finicky in some instances, the performance is exceptionally high. For a low voltage application, it's my first choice. I'm glad to see it finally being specified for a major DIY project.

.

hopeless, obviously you did not read my earlier post about one of the most important selection critera for this DAC -- due to the low supply voltage, it must swing very close to the rails or we'll encounter clipping at 0dBFS. Not just any rail-to-rail opamp would do. The OPA2132 is simply out of the question for this application, and even the OPA2727 that you suggest is not good enough. It could swing to within 150mV of the rails (with a worse-case of 250mV). Compare this to OPA2365 (10mV typical, 20mV max)., and AD8656 (9mV typical, 30mV max).

There are other specifications that are also important in our selection process. And trust me, we've lookedf at many opamps and gone over their datasheets with a fine-toothed comb.

Before we start talking about subjective sound qualities, we must choose opamps that meet all the circuit design requirements first. We narrowed the list down to two, for different uses. The OPA2365 is primary for line-out use only. If you want to drive headphones directly, we recommend AD8656 instead. Not only do our selected opamps meet our technical requirements, we also like their sound very much.

I would be remiss if I didn't also mention that a very highly regarded commercial portable DAC/amp uses two OPA365s (the single version of the OPA2365) in its DAC's analog output stage...

I can see that you are trying to 'help', and I don't like to chastise people for offering opinions...... but AMB and MisterX are designing a compact DAC predominantly for use with USB power. It seems that they have a very good grasp of what is required for working within these constraints.

If it doesn't suit your interests, then don't build one. If it doesn't meet your design criteria, then design something for yourself.

You didn't say what you thought or knew, you wrote some nonsence that well.. didn't make much sence at all...

this continuous BS posting atitute got you banned... so maybe you should rethink your atitude around here...


It has been said by AMB that using external power ISN'T a design goal of this project!!!! Yes, it would be easier, but it isn't for this project. Can't you understand this? Please go trolling another website!!!