Official Jolida JD9 thread

[scorpio333]

Everything seems to be ok. I put the diode back in and had an anxiety filled half hour of feeling if the transformer was overheating or any burning ozone. Ran it for about two hours with nothing bad happening. I looked everywhere I could think of for the JD9F1 schematic and came up empty handed. The JD9F2 schematic is out there, but these boards are very different. Here's an F2 board, note the separate red/orange, blue and brown wires.

Here's an F1 board with the brown and blue tied together:

Putting the pics up and calling out the differences just in case someone else is thinking of doing the diode mod. I wouldn't try it again without a schematic because it's now obvious to me, the F1 and F2 power supplies are very different.

 

[Russ1058]

Hello all, I have recently purchased an unmodified JD-9 and after reading all of the information on the upgrades decided I would like to do this.
The issue is the upgrade information is now many years old and I am not finding the OpAmps and Capacitors listed as available except from China and Ebay etc.
Can anyone steer me in the right direction for the Obbligato Premium Film Caps 1.0 uf 630V and the Burr Brown OPA 627ap's or refer me to the updated versions available today?

 

[AZDean]

The Obbligato's were certainly popular, but I wouldn't limit yourself to them. Read through this thread and you'll find a lot of different ones used out there. I used Clarity ESA which was a noticeable improvement for like $6 each. Go to Parts Connexion and see what they have. I think some have used 637s, so search for those in this thread. I don't remember what's different between those and 627s. I'm using the 627s in two spots, with LT1028 op amps in 4 other positions. I have extras of those if you need them. Parts connexion does have 627au surface mount op amps. They probably have sockets to solder them to so you can plug them in.

 

[jrcotner]

I bought my Jolida JD-9 in 2003, and the previous owner got the level 3 upgrades from PCX at some unknown time. Any idea if, or when, some of these parts need to be replaced again?

Thanks,

John Cotner
New Ulm, MN

 

[jrcotner]

I just got a Sota Sapphire with a Rega 330 tonearm and a Hana EL cartridge, and want to dial in my pre-2000 Jolida JD-9 for optimum performance. Is it okay to change the DIP switch settings while the unit is on and running? Any thoughts on settings for this cartridge? I have the DIP setting chart for a 2006 model, but can't find one for my older model. Are the settings the same?

 

[heyraz]

You don't want to switch anything while powered up.

Suggested Load Impedance for that cartridge is >400Ω

That cartridge is fairly low output (0.5mv) so you're going to need a lot of gain.

I had that preamp and wasn't happy when using a Grado Sonata (0.5mv). When set for high gain, the JD-9 was "hissy" and didn't sound "natural".

If you can open your JD-9 and compare the resistors and capacitors at the DIP switches to a current schematic, you'll have a better idea of how to set them.

Play with the DIP switches, see if you like what you hear. If the JD-9 is too "hissy" with high gain, maybe consider a step up transformer.

 

[Renpar61]

I've owned a used JD9 for a few years. Previous owners had done some mods. The inside of the chassis is all lined with damping material. The wiring has chunky chokes (I don't think they are standard). I can't say if caps have been replaced as well, I'm not tech savvy enough.
Reading here and there I wanted to further improve the sound with easy mods (I'm not going to solder anything), so i replaced the 2 opamps on the left side (output?) with Burson V5i-S and the improvement was immediate.
Now I bought 4 more Burson opamps for the other positions. On Burson's website there are reviews by a couple of JD9 owners who have done the same replacement in all 6 positions with V5i-S and are apparently happy with it.

In my case the result is a considerable increase in noise floor, before the unit was very quiet, now the hissing noise is audible from the listening position even at moderately low volume. It does sound great overall, but I can't explain the hissing. If I had to guess, it's 3-4 times noisier than before, which can't be justified even with some additional gain.
Cartridge is Hana SL low output MC.
I tried swapping tubes (5751 for 12AX7), tried hi and low output jacks, played with gain settings. The differences were very marginal, the hissing noise remains at unacceptable levels.

I wonder if other people who with the V5i have experienced the same, or if there's any fix.
Please help.

 

[seifreit]

In my case the result is a considerable increase in noise floor,

Did you try removing the Burson op amps and putting the old ones back in to see if the noise goes away? The op amps in the initial gain stages are running on only +/- 5v as opposed to the final stage which runs on +/- 15v. Maybe the Bursons don't like running at the lower voltage.

 

[Renpar61]

Did you try removing the Burson op amps and putting the old ones back in to see if the noise goes away? The op amps in the initial gain stages are running on only +/- 5v as opposed to the final stage which runs on +/- 15v. Maybe the Bursons don't like running at the lower voltage.

I haven't yet. It was running quiet with the old ones until replacement, so I would say it should, if I put the old ones back.
What you say would make perfect sense, I'm wondering why other people with the same mod on the JD9 are happy and are not reporting the same problem.
Since you sound way more competent than I am , just to confirm: the final stage is the one circled in red on the photo, the gain stages are the 4 on the right side?

If your theory is correct, I should just return the Bursons, and maybe look for 627s or 637s.
I need guidance...

 

[seifreit]

Since you sound way more competent than I am , just to confirm: the final stage is the one circled in red on the photo, the gain stages are the 4 on the right side?

I can't speak to the competent part(lol) but yes, the op amps circled in red are the final gain stage which operates at +/- 15v. The four large semiconductors that sit between the final gain stage and the initial gain stages are the +/- 5v regulators that drop the voltage down to the other 4 op amps. I am getting ready to try some of the Sparkos discrete op amps in mine. I talked with them about the operating voltages and they say their op amps should work ok in the lower voltage sections but it is at the bottom of their voltage requirements too. I'm going to try the Sparkos in different locations to see how they do. I'll keep the thread posted of my results.

 

[Renpar61]

I can't speak to the competent part(lol) but yes, the op amps circled in red are the final gain stage which operates at +/- 15v. The four large semiconductors that sit between the final gain stage and the initial gain stages are the +/- 5v regulators that drop the voltage down to the other 4 op amps. I am getting ready to try some of the Sparkos discrete op amps in mine. I talked with them about the operating voltages and they say their op amps should work ok in the lower voltage sections but it is at the bottom of their voltage requirements too. I'm going to try the Sparkos in different locations to see how they do. I'll keep the thread posted of my results.

In the meantime I put the old (original?) opamps back in the input stages. All back to normal, JD9 is very quiet. Lost a bit of the "sparkle" of the Bursons, they gave a more rounded presentation, but the hiss was too much. It sounded like added gain, which you don't really need with the JD9. Maybe with a MM cart it would have been be easier to keep the noise floor in check.
I sent Burson an email to share my experience, let's see what they say. I should still be able to return the parts.

 

[seifreit]

In the meantime I put the old (original?) opamps back in the input stages. All back to normal, JD9 is very quiet. Lost a bit of the "sparkle" of the Bursons, they gave a more rounded presentation, but the hiss was too much. It sounded like added gain, which you don't really need with the JD9. Maybe with a MM cart it would have been be easier to keep the noise floor in check.
I sent Burson an email to share my experience, let's see what they say. I should still be able to return the parts.

Maybe try the Bursons in the final gain stage only and see if you still have the lower noise floor but get a little of your "sparkle" back.

 

[Renpar61]

Update: I kept the Bursons in the output stage position and changed the input stage opamps to LT1115CN8. Wonderful combo. The JD9 is now almost completely silent, I have to turn the volume knob past half mark to start hearing any background noise. Performance is now clean and transparent, with reduced noise floor.
I'm sure there are better phono stages out there (Synthesis Roma 79DC is still on top of my wishlist), but I can't imagine anything better at this price point.

 

[seifreit]

I finally found time to install a pair of Sparkos Labs discrete op amps into the spots 5/6(final gain stage). Had to reposition a couple of the big orange caps by un-soldering them and re-bending the leads so they sit further away from the op amps. The only other mods to the JD-9 so far are the standard Obligatto 1uf output caps and vibration damping to the chassis. Those were done a few months ago when I acquired it.

The immediate thing that hit me as soon as the first song started playing was the improvement in bass slam/impact and tightness. It is a significant step up in that area. This is not unexpected as I have installed the same Sparkos discrete op amps in my NAD 116 preamp last spring and noticed the same improvement along with more depth in the sound stage. Only listened to a couple LPs so far so still analyzing what I am hearing. It's a bit tricky to hear increased sound stage in any dimension when at least a third of my listening is to old mono Jazz recordings. I may take the leap and buy another pair to try in one of the other gain stages.

 

[Boonaroo]

Just joined the club. I needed a phono pre to use while my Pro-Ject Phone Box RS is being serviced.

I purchase a significantly upgraded JD9 on US Audio Mart from what appears to be a member here. If it is you @AZDean, thanks for the great deal and doing the research and work that would have taken me months to do. I look forward to hearing the "warm" sound people describe.

Once I get the Pro-Ject back it will be interesting to do a shoot-out. It is very 'analytical' but can be dialed in pretty well to suit my taste. I look forward to having both!!!

​

 

[AZDean]

Hey @Boonaroo it is me. I should get it shipped out tomorrow. I'll be curious how it compares with the Pro-Ject. I have a Pro-Ject Perspective and a SoundSmith Carmen that I used it with.

 

[Boonaroo]

Received my Jolida JD9 from @AZDean and I am quite impressed. I don't know what this used to sound like stock, but it sounds so nice in my system. I have a new power cord on the way and will be trying a few more different cables. Right now I like the way Transparent MusicLink Plus sounds.

My system is almost where I want it. Just a few more tweaks and I will be set. . . .

 

[kward]

Has anyone tried the Analog Devices AD797 in their JD9? What have been your experiences with this op amp in the Jolida JD9?

I have read that since it has such a high gain bandwidth, it can be more prone to oscillate unless the power rail is well decoupled. I don't have my JD9 anymore but thinking about this upgrade for a friend who does have a JD9 MkII.

Or would it just be better for fork out the "bigger bucks" and get the Burr Brown/Texas Instruments OPA627? These are no longer offered in DIP-8 socket format, but they are still available from speciality markets.