Are you wanting the older 'better' DAC that was used in earlier versions ? Even if could replace it, most say the difference will not be audible.

 

Thats whats motivating the question yeah, but it also just got me generally curious about whether it could be done? Like could i install an ultra premium dac chip or is it just not that simple?

 

Just not that simple. The input and output stages are tailor made for the chip used. Not to mention most are surface mount so getting the old off the board and the new one on would require some pretty substantial equipment. Not to mention pin-outs and PCB differences.

 

Buy a separate DAC and be done with it.

 

Sure, anything is possible. Do you have a graduate degree in electrical engineering and access to advanced SMT rework equipment?

 

An AV receiver is an extremely compromised piece of equipment. It’s made to be a jack of all trades with every feature under the sun at a specific price point. I doubt even the most “premium” DAC chip would make any difference.

 

Don't want to hijack the thread, but if I could by-pass my DAC until I finally decide on the replacement, that would be great. I've got the notorious NAD 758V3 which Audio Science awarded a putrid SINAD measurement of 53! This was at the time, the lowest score ever "achieved" at Audio Science. I like the Sony AZ5000 since I got the A80J and can use the TV centre speaker as an additional centre speaker. The thing is, is that the Sony is 7.6 inches in height and cannot be wedged under my TV stand which is where my NAD resides.

Review and Measurements of NAD T758 V3 AVR

This is a review and detailed measurements of the NAD T758 V3 Home Theater Audio/Video Receiver (AVR). It was kindly sent to me by a member. The T758 appears to have been released last year and costs US $1,399. The T758 is quite a bit heavier than recently measured AVRs and has a serious...

www.audiosciencereview.com

 

I've got the notorious NAD 758V3 which Audio Science awarded a putrid SINAD measurement of 53!

Any other reviews with measurements that confirm Amir's findings?
I wouldn't come to any conclusion based on one forum's results.

 

Most designers say which dac chips really aren't that important. It's the implementation of everything else that matters.

So to answer your question, even if you could do it, you shouldn't.

 

This is a lot of effort for zero gain. If you want improvements to sound quality, there are many other things to consider. External DAC would probably be worse since you give up room correction, which makes obvious audible changes.

 

How would one integrate an external DAC in the 3700?

 

I think digital optical output to a DAC, but you'd be limited to the capability of optical.

 

The 3700 has the better AKM dac compared to the Texas Instruments cheaper dac on the newest Denon receivers. I wouldn't even think of touching that.

 

You can't change the DAC in your AVR. If you want a better DAC, then run your component or a PC into a cheap Topping external DAC and then analog to your Denon. You'll want to work thru the various Direct options to get the "purest" source signal. Of course the source content matters, but I doubt you are going to hear any difference. Your speakers have more distortion than any DAC or amp in the chain before them. Your current setup beyond the AVR would be helpful.

 

An external DAC would be for 2-channels only.

 

Most of the replies seem to focus on the merit of the endeavor rather than directly answering the question, so I'll go out on a limb and say that it's possible that you could make the swap. To make that determination , you'd want to look at the existing vs replacement chip pinouts as shown in the MGF's(eg. TI or AD etc) catalog cut sheets. You may find that families of DAC's share common architecture(even between MGF's), and so allow for direct substitution. Even if there are differences in pin locations but identical functionality, you can still do it by piggybacking the new chip on top of the existing one. Note that some pins may be unneeded for your application.

To do this, you cut the pin(s) to break the connection(s) that supply power to the existing chip, then, use fine gauge wire(ie wire wrap wire) for jumpers. Verify that there are no conflicting polarities between the old and the new chip's pinouts for the remaining uncut pins. Alternately, you can bend up the unmatched pins of the replacement chip and still use jumpers; if you wanted to remove the existing chip altogether. There should be no need however, since the input impedance of the existing chip and those associated should be quite high, allowing for the additional fanout. Using the piggyback technique saves you from having to rework(reflow) the board. You can use a conventional soldering iron using the piggyback method.

If you do choose to rework the board, it's still very possible using an oven, paste and desoldering equipment, which can be obtained rather inexpensively on ebay, Jameco, Digikey etc. Rework kits and equipment are available as well. The rework comes down to heating the existing chip to remove it, then applying solder paste to the pins of the new chip and setting it in place over the pads on the board, then putting the whole thing in a ~400F oven(eg toaster oven) or use a heat gun. Alternately, you can cut the pins off the existing chip to remove it, then use a conventional soldering iron(or hot air gun) to remove the pins individually with tweezers. This latter approach is my preferred method since it doesn't involve repeated heat cycling of the entire board.

One other thought is that you could solder leads directly to the existing DAC chip pins to bring the digital signals out to a header. From there you could build a piggy back board or externally convert it to a serial bitstream/USB output etc. as required for use with a conventional standalone DAC.

I've had good success repairing and modifying SMD boards using these techniques. It's not hard or particularly expensive, but requires some patience and maybe magnifying glasses(or excellent vision). As others have said, unless your existing DAC is truly awful, you'll likely not hear the difference, but if you want to do it for fun, it's very possibly done. The methodology of signal conversion interface is pretty well established and fairly standardized, so there is usually more commonality than not between devices.

 

Recently bought a Fosi DAC from Amazon. It's good enough for me. And you can't beat the price.

 

No one has mentioned that the instruction set, aka software, for the DAC would need to written to the AVR firmware. Therefore that pipe should remain in the land of dreams cause it aint happening.