Jolida JD9 -- New Op Amps on the Way!!

Discussion in 'Audio Hardware' started by stereoguy, Mar 13, 2018.

  1. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn
    So, with my purchase of the new Rega Planar 2, White belt, cork mat, etc, I'm also going to upgrade the op amps in my Joilda JD9 phono stage.

    Doing my research, most recommended getting (6) Burr Brown OPA 627AP replacements for around $25 bucks each.

    Well, to my surprise, Burr Brown has been bought by Texas Instruments. But, they do carry the OPA 627 for $27 (inflation, you know).

    So, I have 6 on the way. I just hope that they are they same specs as the original Burr Brown were. We will see, but my hunch is they HAVE to be better sounding than the cheapo $4 chips that Jolida used, to get to their price point.
     
    Dmann201, PhxJohn and bajaed like this.
  2. bajaed

    bajaed Forum Resident

    Let us know what differences you hear. I have a JD9 and would be interested in trying the upgrade.
     
  3. PhxJohn

    PhxJohn Forum Resident

    Location:
    Phoenix, AZ
    This is CD stuff ?
     
  4. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn

    No John...its my phono preamp for the Rega Planar 2.
     
    PhxJohn likes this.
  5. PhxJohn

    PhxJohn Forum Resident

    Location:
    Phoenix, AZ
    The Burr Brown is what threw me. I think I have seen that name mentioned in relation to CD decks. They have amps. LOL.
     
  6. allied333

    allied333 Forum Resident

    Location:
    waterford, mi
    I used to use the Burr Brown OPA2134 to upgrade vintage receivers. The OPA 627 is an upgrade to the OPA 2134
     
  7. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn
    Thanks allied333.....at $27 bucks each, i certainly hope so!
     
  8. slovell

    slovell Retired Mudshark

    Location:
    Chesnee, SC, USA
    I've got them in my JD-9. More detail, smoother sound, blacker background. Enjoy!
     
  9. PhxJohn

    PhxJohn Forum Resident

    Location:
    Phoenix, AZ
    Are op amps used to provide gain ? Does it mean the Jolida preamp is a hybrid of sorts as opposed to a total vacuum tube design ?
     
  10. Gibsonian

    Gibsonian Forum Resident

    Location:
    Iowa, USA
    627 is one of the best single channel opamps I've tried. Why the supercost in comparison to others, must be market driven, as process and materials can't be that much different over others. Possibly volume related but they can get it so they do. Think you will be pleased.
     
  11. slovell

    slovell Retired Mudshark

    Location:
    Chesnee, SC, USA
    To my knowledge it's a hybrid design (correct me if I'm wrong) but rolling the tubes will improve the sound as will upgrading the op amps. It has tons of gain and is very adjustable. Beware of fake, cheap Chinese op amps for sale on ebay.
     
    PhxJohn likes this.
  12. StimpyWan

    StimpyWan Forum Resident

    Maverick Audio has an Upgrade page for their various Dac's and headphone amps. They offer matched pairs of OPA 627 op amps, for $30 a pair. It seems like a good price, considering the new TI direct pricing.
     
  13. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn
    Thanks Stimpy. I would think, that at $15 each, those are a cheaply made version of that chip.
     
  14. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn
    Well, the upgrade is complete. I was a nervous wreck putting the new chips in, trying not to bend any pins. True to form, the LAST chip gave me problems...wouldnt go in straight, bent pins, etc.

    But, I manged to get them all in, and since there is audio in both channels, I think I did that part right.

    So...to the listening test:

    My first impressions are that these dont sound much different than the old chips, in fact, I *think* I hear a bit of brassiness to the sound which wasnt there before. Stereo sep is still excellent.
    My hunch is these may need some time to break in. What do you guys think?

    Stereoguy.
     
  15. Davey

    Davey define a transparent dream

    Location:
    SF Bay Area, USA
    Hopefully the people making the recommendations looked at the BB/TI layout guidelines and have an oscilloscope to check for proper operation. Stability and oscillation is always a potential issue when replacing opamps with high gain wideband amplifiers in applications using lots of negative feedback. If the harshness continues, you may want to try some low ESR bypass capacitors on the opamp power pins. But may just be a difference in sound as you suspect, there can be some very substantial differences in opamps since you are replacing a module with a large number of transistors and circuit design choices... not meant as any kind of criticism, and not trying to be an alarmist :)
     
    Last edited: Mar 16, 2018
  16. levimax

    levimax Well-Known Member

    Location:
    California
    Replacing an Op Amp which a circuit was designed around (with negative feedback) with another "possibly higher performance" Op Amp would be unlikely to make much of any difference. Any decent Op Amps can be very good if the circuit is designed properly and negative feedback will cause any differences in the Op Amps to be minimized. It is fun to play around with stuff like this but I like to take "before" and "after" measurements (Oscilloscope and Spectrum analyser) when I make changes ..... "trust your ears" only goes so far ... measurements really can help you see if you are on the right track, wrong track, or most common of all the "no difference" track.
     
  17. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn
    Well, there are many websites on upgrading the Jolida JD9, and they all refer to the OPA 627 as the preferred upgrade for the op amp. Could they all be wrong>?
     
  18. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn

    Gib, did yours take some time "break in" or did you notice the improvement right away?
     
  19. Gibsonian

    Gibsonian Forum Resident

    Location:
    Iowa, USA
    Was immediate
     
  20. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn
    Ok, thanks.
     
  21. Gibsonian

    Gibsonian Forum Resident

    Location:
    Iowa, USA
    Sounding any better yet?

    Did you buy from Digikey/Mouser? Counterfeits out of China out there I know.
     
  22. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn
    Gibs:

    I havent played it today, maybe tonight .

    Yes, bought at Mouser.
     
  23. stereoguy

    stereoguy The King Of Stereo Mixing Thread Starter

    Location:
    Brooklyn
    Ok, played some Lps tonight!!

    Sound is much better to me tonight, dont know why.

    Among other things, I played The Beatles Horzu version of "Please Please Me" and it was clear as a bell! I'm hearing little things I never noticed before, especially in "Ask Me Why" (but dont Ask Me Why!).

    Satisfied at this point.
     

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