Opamps and Modding thread.

Discussion in 'Soundcards, Speakers HiFI & File formats' started by ROBSCIX, Mar 7, 2008.

  1. angershark

    angershark Master Guru

    Messages:
    339
    Likes Received:
    0
    GPU:
    AMD
    Built some more LME49990 to try in both I/V and buffer, I think they are going to stay in there for a while.

    :rock:
     
  2. angershark

    angershark Master Guru

    Messages:
    339
    Likes Received:
    0
    GPU:
    AMD
    I rolled back to 49720's for now. I don't know if the 49990's are entirely stable in the i/v slots, they get quite hot to the touch even though they sound fine.
     
  3. ROBSCIX

    ROBSCIX Ancient Guru

    Messages:
    16,241
    Likes Received:
    8
    GPU:
    22" LCD on GTX260 C216
    All opamps will generate some heat but if they are getting hot to the touch, chances are they are oscillating. It may be high frequency and although you cannot hear it, your opamps are not operating properly.
     
  4. analogic

    analogic Active Member

    Messages:
    63
    Likes Received:
    0
    GPU:
    Radeon HD 6870 975/1200
    I observed the same thing with LME49990. Data sheet for the IC says the SOIC package has a thermal resistance of 145 C/W.
    Even at low power dissipation they will get hot!

    Forgot to make it easy...
    http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=lme49990&fileType=pdf
     
    Last edited: Nov 22, 2012

  5. Mkilbride2599

    Mkilbride2599 Banned

    Messages:
    17
    Likes Received:
    0
    GPU:
    GTX 670 SLI
    So what kind of Opamps are good for Headphones, where I want crisp, and clear audio, not warm or really to bass heavy.

    Going to get a Titanium HD and thinking of picking up some that go well with headsets.
     
  6. Radical_53

    Radical_53 Ancient Guru

    Messages:
    3,929
    Likes Received:
    90
    GPU:
    Aorus 1080 TI
    The original opamps already are quite bright and clear, don't you think?
     
  7. ROBSCIX

    ROBSCIX Ancient Guru

    Messages:
    16,241
    Likes Received:
    8
    GPU:
    22" LCD on GTX260 C216
    If you are getting a new card...wait!
    Wait for about a week to get a good idea of how the stock signature sounds.
    After that time, if you still want to swap opamps..go ahead.
     
  8. analogic

    analogic Active Member

    Messages:
    63
    Likes Received:
    0
    GPU:
    Radeon HD 6870 975/1200


    I finally found some TI “SoundPlus” OPA1642 on DIP adapters at a decent price. (via eBay from an audio engineer in Hungary)
    I replaced the AD797BR DIP adapters in 4 I/V channels on my Essence ST Deluxe. My first impressions are very favorable toward using these JFET input op amps in I/V circuits on the Essence ST/H6
    The ICs are like OPA2134 (JFET input op-amps) on steroids is my best description. The familiar Burr-Brown “warm” sound is quite excellent.
     
  9. ROBSCIX

    ROBSCIX Ancient Guru

    Messages:
    16,241
    Likes Received:
    8
    GPU:
    22" LCD on GTX260 C216
    IIRC, the 1642's and 1641's are great sounding chips. With audio opamps, I always prefer to build stereo modules out of two dual chips. Just seems to keep the signal a bit cleaner.

    To note, I have built custom modules for quite a few people in the audio community, so if you ever need anything custom built. Drop me a line and I will see if I can help you out.
     
  10. analogic

    analogic Active Member

    Messages:
    63
    Likes Received:
    0
    GPU:
    Radeon HD 6870 975/1200
    Guess you meant 2 single channel op amps per DIP adapter, like the LME49990 and the AD797BR. Both are very nice, but I thought the AD797BR had kind of "aggressive" sounding.

    Certainly, this was more noticeable on my new Harman-Kardon AVR2600 with Polk & BIC speakers.
     

  11. ROBSCIX

    ROBSCIX Ancient Guru

    Messages:
    16,241
    Likes Received:
    8
    GPU:
    22" LCD on GTX260 C216
    Yes, using two single(mono) channel opamps instead of a stereo module. I find in my comparisons anyway, the dual mono channels are just a bit cleaner over the stereo module.

    Many people love the AD797BR, but IMO, there are "better" and they are so unstable in many situations, so they are not the best for people new to opamps without a great deal of background in electronics. There is no one best opamp, I consider them like different flavors some like this one and some like that one. What sounds the best to you, is the best. Simple as that.
     
  12. z3d

    z3d Member

    Messages:
    10
    Likes Received:
    0
    GPU:
    Zotac GTX680
    Hello, a little update.

    I changed the opamp in my setup (Essence STX-> Subwoofer m-audio sbx10-> monitor m-audio bx8 d2) and tried those setups:

    2x JRC 2114D + 1 LM4562 - stock
    2x LME49860 + 1 LM4562
    2x LME49860 + 1 LT1364
    3x LME49860

    At stock the sound sounded too much bright or even harsh (I mean when you have high /very high frequencies in a song it hurts your ears).
    Another thing I noticed is that you feel the music being on the same floor, not if like each instrument and voices would have their own space into the song and flowing "separately" to you and I prefer more separation and details.

    Changing the two JRC2114D with two LME49860 changed this behaviour and now I'm ok with that.

    The best setup was finally 2x LME49860 + 1 LM4562 because in the other setups the music fur up (I don't know if it's the right word in english).

    So, now I'd like to improve a bit with the Buffer op-amp because there are still some things that I don't like but now it's hard to say what.
    I notice something I'm not linking expecially when listening to music at medium/low volume, I don't know if this information can help.

    So, can you give me an advice about some good op-amps as buffer which could fit in my setup?

    Thank you very much guys :)
     
    Last edited: Jan 23, 2013
  13. ROBSCIX

    ROBSCIX Ancient Guru

    Messages:
    16,241
    Likes Received:
    8
    GPU:
    22" LCD on GTX260 C216
    I always remind people to keep in mind that their system is a chain so you can only put so much of the signature on the source. Which is why it is great you can change opamps as that way you can dial in your source to best suit your amp/speaker system.

    If you like the LM4562 for the buffer, try a LME49720 or the best of that family the LME49710HA module.

    The HA are metal can opamps and the LME49710HA is a single channel so you require two of them with an adapter but they are excellent and have a similar signature to the LM4562/LME49720 but with further refinements. Better imaging, separation, just overall nicer qualities...
     
  14. z3d

    z3d Member

    Messages:
    10
    Likes Received:
    0
    GPU:
    Zotac GTX680
    Thank you for the help ROBSCIX :)

    Well, I tried a LME49860 on Buffer but I prefer the stock LM4562: both those and LME49720/LME49710 aren't all in the same family?
    About the LME49710, it is stable on asus essence stx soundcards or it run hot or give stability problems?

    What about a 6172, it could fit or it will be a downgrade in your opinion?
     
  15. ROBSCIX

    ROBSCIX Ancient Guru

    Messages:
    16,241
    Likes Received:
    8
    GPU:
    22" LCD on GTX260 C216
    They are in the same family but different version, the TO-99 metal can opamps are higher quality over the chip opamps. The dual single channel modules sound better over a dual channel opamp.

    The LME49860 is not really the same...
     

  16. GenClaymore

    GenClaymore Ancient Guru

    Messages:
    6,153
    Likes Received:
    65
    GPU:
    XFX 5700 XT Thic II
    Also Linear do have some good op-amps as well, I just can't really remember all the ones that I tried. Other then the LT1213 and LT1155 that I like, I had more. But since I haven't rolled op-amps in a very long time, ever since switching to this Audio-GD NFB-12 rev2, I just don't remember.
     
  17. Tom F

    Tom F Ancient Guru

    Messages:
    2,822
    Likes Received:
    0
    GPU:
    Saab 900
    I remember reading an article ages ago about comparing a whole bunch of different opamps with some very high quality equipment.

    Don't have a link, but they all wound up measuring about the same - in the end the guy picked the AD797 as the winner because that was what the analyser had in it ;)

    Tricky beasts though by all accounts - treat them with respect. Would be an expensive chip to cook due to it oscillating!

    A lot of the ones mentioned here are very fast indeed and could be ringing at some MHz which you will never hear. Even the lowly 2134 can do this in some circumstances - checking for instability gets very important when using these insanely fast (say >50MHz GBW) chips.

    We've got something at work which uses four opamps with a 1.6GHz GBW - haven't tried those in an audio circuit though lol
     
  18. z3d

    z3d Member

    Messages:
    10
    Likes Received:
    0
    GPU:
    Zotac GTX680
    Hi again, I made a big mistake explaining the op-amps I tried because I didn't try the LME49860 in I/V but the AD8620ARZ instead!

    So it follows the right reply after doing some rolling:
    And this:


    As now, after some burn-in, I still feel the highs being harsh (even if less than before) with 2xAD8620ARZ and 1x LM4562 configuration.
    My thoughts are that the asus essence stx is too bright (or harsh) in the highs and with my monitor speakers (m audio bx8+m audio sbx10 subwoofer) and my headphone (ultrasone 780) which are quite neutral I need some op amp with warm sound signature to roll off the highs that are still hurting me.

    So said, I found those that could fit:
    opa827
    opa2227
    opa2111kp
    lme49860
    lme49720

    What do you think about those?

    Thanks very much to all :)
     
  19. GenClaymore

    GenClaymore Ancient Guru

    Messages:
    6,153
    Likes Received:
    65
    GPU:
    XFX 5700 XT Thic II
    Try the LT1057ACN8 cant remember exactly which linear OP-amp I used, Which gave me that sound signature. I haven't roll op-amps in a very long time and i don't have my notes any more.

    If I remember then I will try to mention them that might work for you, it just I stopped rolling op-amps, The memory of how each one sound went with it.
     
    Last edited: Feb 8, 2013
  20. analogic

    analogic Active Member

    Messages:
    63
    Likes Received:
    0
    GPU:
    Radeon HD 6870 975/1200
    Yes, IMO the AD8620AR and the LM4562 are very neutral op amps. That is why they are good! I don't find it sensible to play with sound equalization on the back end of the D/A signal chain. (sorry if I didn't say humble)
     
    Last edited: Feb 10, 2013

Share This Page