a "little" project I just did

Discussion in 'Tech Talk' started by EniGmA1987, Feb 28, 2011.

  1. EniGmA1987
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    So I have been wanting to use the legendary AD797BRZ op amp for a long time but never got around to it because of the high difficulty in acquiring one of them, the cost of them each, the fact that it only comes in one design type that doesn't work with any of my hardware, and general laziness. So I finally managed to buy a few, as well as some PCB boards and header pins to create an adapter so I could use these op amps in my nice headphone amp. Anyway, I never really considered myself that great at soldering, I don't own a soldering iron, and I haven't soldered anything in at least a few years, and never anything close to a piece as small as an 8 leg SOIC chip. Anyway, I went out and bought a $9 soldering iron and some slightly "high end" solder (2% silver in it, whoopdy do). Came home, plugged in my heat gun that was recommended to me by a person very good at this stuff as being much easier for most of the work needed only to find that the heat gun in the box I borrowed from work was a used gun that was broken. So I had to do everything by hand. Here are the results (I left a couple legs unsoldered as they are not used):




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    yes you do see that correctly, the entire unit consisting of both AD797BRZ units, the PCB board, and the header pins is smaller than my thumbnail...
    Pretty good for my first attempt I think :D

    The AD797BRZ is not used in anything except custom stuff to my knowledge, the AD797ANZ is the "famous" really nice sounding audio op amp that people rave about (that and the OPA627). The "B" version is far and above better sounding and higher quality than the "A" version people love so much. Also costs $11 each though...





    This is the DAC and headphone amp I am using it in:

    [​IMG]
     
  2. Vandiego
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    I'm guessing it worked? :)
     
  3. EniGmA1987
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    Yep, sounds really great too :D
     
  4. Sogetsu
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    The most important question.
     
  5. EF2
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    I wish I was more of an audiophile to attempt something like this. Nice job.
     
  6. Valars
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    No clue what it is .... but am glad it worked out for u!
    LOL
     
  7. Terand
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    I am an audio guy myself, Not necessarily an audiophile but a tone chaser. Good work on the chip man. How you liking it so far?
     
  8. EniGmA1987
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    Best sounding op amp I have ever heard before. Granted I haven't heard a TON, but I have had the chance to hear:

    LT1028
    NJE4850 (I think, default for many good sound cards. HT Omega stuff and ASUS Essence line)
    OPA627
    OPA2132
    OPA2134
    OPA-Moon
    OPA-Earth
    AD797B

    And I have read reviews on many more and read peoples impressions.
    Terand, if you want me to build you one of these I can. I have enough op amps to make a second adapter. You just need your audio equipment to have a DIP socket for op amps in its output stage. Most modern equipment does now days since opamp rolling is so common. Like tube rolling back in the day. These adapters are for dual channel op amps, not single channel. I can make two single channel adapters for this if you want, but I dont actually have the PCB boards for that right now and would have to order them. I can only make one dual or two singles right now. If you want/need more than that then you will need to Paypal me some money so I can buy more of the op amps.

    The 797B is my favorite of all, it doesn't emphasize anything and is very neutral sounding. But not like most neutral sounding amps, this one has a perfect balance of all frequencies, incredibly tight bass, crisp highs, nice mids, airy sounding yet full at the same time. The one possibly negative thing I could say about the AD797BRZ that isn't really a negative is that the vocals may seem a tiny bit de-emphasized at first compared to other op amps. This isn't really the case, it is just that nearly all other amps (even neutral sounding ones) tend to emphasize the vocals a little. After a day you are used to it and it sounds perfectly natural. Im hearing a lot more small details in many songs that I didn't notice much before even with my other nice op amps.



    My second favorite op amp would probably be the OPA2134, which is pretty similar to the OPA-Earth. The OPA-Earth has a bit more bass, but the bass isnt as tight sounding as the OPA2134.


    The OPA-Moon is quite warm and slightly de-emphasizes the highs. A bit too much for me, especially with my already warm sounding headphones. (Sennheiser PC-350s with "hero mod")






    Next project: Building my own home theater receiver. Two HDMI inputs (for XBox and cable box), capable of decoding all audio formats including lossless, an optical and coaxial SPDIF input, and a bit perfect USB input for computer sources. ES9018 DAC chip (only one :(). Volume control is done via current manipulation rather than voltage (sounds WAY better), and will have a high end diamond buffer output stage. Including 7 channels of power amps providing a true 400 watts per channel @ 4ohms with nearly linear bandwidth from 10Hz to 400 kHz. 5 stage independent voltage regulation for each power amp channel. Balanced XLR and RCA output connections.
     
    Last edited: Mar 4, 2011