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Yamaha CX-1 Thread

Discussion in 'Yamaha' started by Bratwurst7s, Sep 30, 2017.

  1. DeltaB

    DeltaB Active Member

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    I am familiar with the card, and some of the suggestions. There have been some changes in what we have to choose from. The original LM4562 are actually a fairly decent performer, but I'm not a fan of the JRC. The real issue is what is available in DIP format. The LM4562 (original) and the LME49720 (your replacement) are actually the same die. If you do choose to replace the OPA-2107 with the OPA-1612, you really do need it to be as close to the board as possible. So if you mount it on an adapter board and settle on it, I would remove the socket and place the adapter directly into the board to get it as close to the ground plane as possible.
     
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  2. Klascala

    Klascala New Member

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    10
    I've swapped op-amps in my Revox B226 CD player and in two different active crossovers. I really like LM4562 but you have to play around with local decoupling until it sounds good. It can sound really wrong with the wrong decoupling... plus it sounds sharp and thin for a good 100 hours before mellowing down. I'm sure some of us dismiss it before giving it time to settle. Another one I like and is less finicky to use is OPA2132, sounds better than OPA2134 and is as easy to use. I've never tried OPA1612 or 2107, OPA1612 sure looks like the holy grail of ICs looking at specs! Pity it's not DIP-8...
     
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  3. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Am I correct in guessing that you would recommend doing this with an amp or cd player also? (Getting it as close to the ground plane as possible.)

    Cheers,
    James
     
  4. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    I didn't really believe this until I actually swapped some op-amps and found to my surprise that the really do start to sound better after 60+ hours of use. And to address the "that's just your brain and ears getting used to the change" argument that often gets stated, I've taken 2 otherwise identical cd players and the one with brand new op-amps sounded more harsh than the one with 2 months of use. So this is me agreeing with you. :)

    Cheers,
    James
     
  5. DeltaB

    DeltaB Active Member

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    Just keep in mind, one of the shortcomings of DIP, and one of the reasons SMT technologies must come into the picture, is decoupling very close to the device, and with very short leads and close to the ground plane. This is how something like the OPA-1612 can achieve the specs it does. With riser boards, there really is no way to effectively decouple it within very close proximity (within a couple of mm) and no ground plane.

    I can say, in my own experience, my Avantage goes from so-so SQ with the original NE5532's to reference SQ with the OPA-1612. ESS will tell you strait up, even in their lowest performing DAC, the NE5532 is the lowest of the scale in acceptable performance, and in their better DAC's it isn't even on the choice list. It just doesn't have the performance required. I really do wish that Yamaha would finally figure out, we as consumers would be willing to pay an additional 10% (to cover the cost of the part price for the op-amp) to obtain the better SQ, and they could certainly gain more market share with such, rather than trying to sell that a 5th plastic foot (The Anti-Resonance Technology Wedge) under the center of the chassis is some miracle SQ device.
     
    Last edited: Oct 12, 2018 at 8:06 AM
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  6. dino74

    dino74 AK Subscriber Subscriber

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    Was meant for you! I "unfortunately" bought some more vintage Yamaha gear and as I research them, I come across many of your post and they are very helpful to a newbie like me.
     
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  7. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    That's great! That is mainly why I make these threads, to spread information and let others benefit from my mistakes.

    Cheers,
    James
     
  8. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

    Messages:
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    Location:
    Munich, Germany
    Btw, everybody can laugh at how difficult it was for an old guy to do this, but I finally figured out how to make a pdf file of my parts list and attached it to post # 182. It's perhaps not perfect, but usable I think.

    Cheers,
    James
     
  9. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    Hi DB, a couple of questions/thoughts.

    If I bought an SO8-Dip-8 adapter without stand-off type leads (something like the one below), attached the op-amp, and then laid it directly on the pcb I would be able to just solder some short leads directly through the board/pcb. Would this get me to where you are suggesting going with this? (this is pre-supposing of course that there is room and nothing under the position that can short)

    sop8 dip8 adapter20.jpg
    In "decoupling" do I understand correctly that you are meaning a small (0.1µF?) cap from the supply lines to ground?

    Can you show us a photo or 2 of how you added the 1612 to your amp(s)?

    Also, one thing that I've never seen in any Yamaha amp etc is a part that wasn't of Japanese origin. And the OPA's are from Texas Instruments. I think that we can wait a long time before they use an op-amp that wasn't sourced from Japan.

    Cheers,
    James
     
  10. DeltaB

    DeltaB Active Member

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    James, the adapter shown is not for SOIC, but VSSOP (micro) and the OPA-1612 is not available in that package type, however, the OPA-1602 is. That is an incredibly small package, and very tough to deal with if you don't have a x10 scope and proper tools. But from a concept perspective, yes, the closer you get the SOIC to the board and the shorter the leads, the better off you are, but through hole technology doesn't utilize multi-layer boards with ground planes.

    Concerning decoupling, yes, I was speaking to properly decoupling the supply. My Avantage is already SMT based and no mods to the boards, or adapters were required. Simply removing the NE5532 (SOIC) and replacing it.

    Most of what Yamaha is selling this past decade from an AVR perspective has a number of TI parts, including the DSP's. The original NE5532's are TI chips. The real issue here is that NE5532 are $0.25 and OPA-1612 are $4.00. Profit margin dictates this decision.
     
    Last edited: Oct 13, 2018 at 5:02 AM
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