Official Jolida JD9 thread

AZDean... I bought my JD9 used about 6yrs ago. Fortunately it was an Underwood modded unit

Of the many things they did these are just three

Install four hi quality coupling, bypass and power supply capacitors
Eight Riken Ohm ½ and one watt 1% carbon com. resistors added in the signal path
Four International Rectifier Hexfred ultra-fast soft recovery diodes installed in the power supply
 
AZ,
I replaced nearly everything on the SS board. I didn't bother replacing the original bridge because I thought any switching noise would be filtered by the capacitors.
I replaced the sockets with gold plated sockets, every resistor with vishay metal film and the ceramic caps with either silver mica or some sort of boxed film cap.
For me, it was easier to remove the board and carefully remove all of the components and sockets (the board is so flimsy you have to be careful not to damage it). Once the board was clean and empty, I built it back up, cleaned it to remove flux and re-installed it.
One note of advice-the schematic has some errors on it, verify each component's value as you replace it.
I also replaced all of the resistors and capacitors on the input board.
 
Wow...this thread is causing me to lose a lot of sleep! I'm only on page 34, but can't stop reading/researching. Great stuff! I have an original JD9 that I bought on recommendation before this thread began. Right away, I threw in some Gold Lion ECC83's - incredibly smooth, quiet, and detailed tubes, worth the $40 price and then some IMO. Soon after, I swapped in some ClarityCap 1.0 MR's which totally blew me away and took this pre to a completely different level. I've never really had the desire to try anything else since doing these mods....until now...I've recently got the itch again and have some op amps ordered. I'm gonna keep plugging away at reading this entire thread while I wait for my chips, but I will post any observed differences once installed. I have a new MC cartridge that is still breaking in, so it may be a little while before I make the switch. My new cart, the Hana SL, is already truly incredible for the price if anybody reading this has been giving her a good long look...Thanks to all who have contributed here. I wish I'd have found this thread years ago.
 
In the process of upgrading both my JD9s (already thru these in my JD5 love them) to these tubes:

http://www.thetubestore.com/Tubes/12AX7-ECC83-Tube-Types/Preferred-Series-7025-12AX7

Kidkoffee, I have a Hana SL in hand awaiting a TT build. Can you share what you loaded your JD9 to? I see the reco specs but have seen others loading to different settings.

Yes...very hard to find info and setup opinions on this cartridge so far. After much headache-enducing fidgeting and experimenting, here's what I've come up with: I am using the high outputs on the JD9 with all gain switches off for 55db gain. KAB recommends 56 +/-2, so this is pretty dead on, and volume should be equal to any other sources in your system. Like I said, I'm still breaking her in, but I am staying with a 1K ohm load for now. I was going between 1K and 300, so I'll play around a little more once I get about 50 hours on, but this thing is blowing me away as is. I think 300 was probably just taming the new cart edginess at first. Hana recommends >400 ohms to get the most out of this one, but I've read a review or 2 where they've loaded It down to 170. In my system, the soundstage really seemed to shrink any lower than 300, but YMMV. Some are in the camp of running all/most MCs at 47K! Sounds crazy, but I've flipped that switch and it wasn't bad at all at about 20 hours...We shall see. I'd start with 1K and, if it sounds a little harsh at first, save yourself the headache, leave it alone, and just listen to it come alive. It started opening up within the first 5-10 hours and continues to do so. I only have about 25 hours on right now, and it is killing my Reference Sonata already. Cannonball Adderley was in my living room earlier tonight :) I like it so much, I almost want to buy another before everyone catches on and prices start to skyrocket! Please let me know what settings you decide on, impressions, etc. Great to find someone else with a JD9 and the Hana. Enjoy!
 
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Okay - So I switched op amps and added a better power cord to the JD9. I think I like what I hear after only about 10 hours. I went the 843, 627, 1028 route. However, I am still noticing an audible hiss at about 12 o'clock volume. This is louder than I normally listen, but I'd still like to reduce/get rid of it. I may try 627s across after I give this setup at least 50 hours...we'll see. I definitely agree that the output caps had the biggest, most dramatic effect of any of the mods I've done, but the op amps seem to be a worthwhile upgrade nonetheless. Can any of you post a link or a closeup pic/instructions on how to swap the power supply caps? I'd like to try this first before anything else. I've read this entire thread and have a good idea based on pics and posts within, but a nice closeup of the soldering points and caps to be removed would be be helpful. Open to suggestions for power supply caps from some of you, now seasoned, JD9 DIY-ers as well, but I can comb back through for that info if need be. Thanks for any help.
 
anyone had the level on mod done by jolida? it's now $300. i'm tempted to do it, but wonder if i'll really gain much.
 
Look back 6 posts to #1901.

Many people have, others do their own version of it.

You can gain a lot but changing OP Amps, output caps, and tubes. The stock version is not even close to what it can be.
 
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Today I plan to add some sound dampening sheets. I was thinking instead of cutting small pieces and fitting them to the bottom interior, would I get the same effect if I cut out the vent holes and applied the full sheet to the bottom exterior?
 
I cut mine out and put them on the inside (see photo by my moniker), did the same for the interior of the lid, cutting out only for the vent holes.
 
I have decided to start the mods on my JD9. I purchased the upgraded version about six months ago and I love It. I'll start out slow (and cheap) with sound dampening. I didn't much like the idea of cutting a bunch of small pieces and fitting them around so I lifted the parts and placed the entire sheet underneath. Done for today. Next upgrade oppamps. Haven't quite decided which ones.

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I have decided to start the mods on my JD9. I purchased the upgraded version about six months ago and I love It. I'll start out slow (and cheap) with sound dampening. I didn't much like the idea of cutting a bunch of small pieces and fitting them around so I lifted the parts and placed the entire sheet underneath. Done for today. Next upgrade oppamps. Haven't quite decided which ones.

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what exactly does the sound dampening material do? i mean i get that it dampens sound, but is that sound that occurs when playing music or just internal noise? also, what op amps are you looking at and why?

thanks!
 
Out with the old in with the new! Today I swapped out the oppamps. I went with TI BB op627ap Pretty straightforward, it took about 20 min. IMG_2490.jpg IMG_2491.jpg

Never could I have imagined the difference. Deeper soundstage, more separation, unbelievable clarity, as if the music just floats in the room. The detail is incredible. Just a whole new level of quality. I highly recommend this mod.
 
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Out with the old in with the new! Today I swapped out the oppamps. I went with TI BB op627ap Pretty straightforward, it took about 20 min. View attachment 896200 View attachment 896202

Wow what A difference! Never could I have imagined the difference. Deeper soundstage, more separation, unbelievable clarity, as if the music just floats in the room. The detail is incredible. Just a whole new level of quality. I highly recommend this mod.

Can you share a link for where you got your opamps. I see them on the Ti site but I can't seem to add them to my cart.
 
Today I plan to add some sound dampening sheets. I was thinking instead of cutting small pieces and fitting them to the bottom interior, would I get the same effect if I cut out the vent holes and applied the full sheet to the bottom exterior?
What was the biggest impact that was made with the sound dampening? I just bought $150 worth of op amps. Wondering what the dampening will benefit me. Thanks
 
I didn't hear much change in the sound when I installed the damping material, however I too changed the opamps to the 627's and found similar improvements to the sound. Easy to do too!
 
I didn't see any real change after adding the dampening sheets. However, I do play my music a bit on the louder side and avoiding unwanted vibrations couldn't hurt. I think the effectiveness of the dampening sheets is more about what you don't hear rather than what you do.
 
Damping benefit is small compared to the output caps and the op amps.

If your preamp is already mounted on a solid shelf the added damping may provide tighter better focus in the low end and less smearing in the high end. It really depends. It's a subtle change.

The major must do more are: (1) Output caps make a major difference. I have Mundorf Supreme's in mine. (2) Op Amps, like opa 627, make a major improvement too.

The next level after these mods is improving the power supply section. Use of better diodes and caps, or bypassing the current electrolytics with film, will make the unit quieter (blacker background).
 
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