Official Jolida JD9 thread

Next I'm swapping out the tubes. The plan is to acquire a pair of NOS Telefunken 12ax7's to put in my amplifier and move the NOS Bugle boy tubes that are in it now to the JD9. As for the caps, the Clarity Caps that came with the factory upgrade are fine for now. I might like to try some Mundorf's in the future but would need a recommendation as to which ones are compatible for the JD9
 
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).
Can you explain more about the caps? What do they change in the sound? Where did you get them? About how much should one expect to spend? What are the details I need to be aware of when shopping? Thanks!!!
 
Can you explain more about the caps? What do they change in the sound? Where did you get them? About how much should one expect to spend? What are the details I need to be aware of when shopping? Thanks!!!

The 1uf output caps in the stock JD9 are low quality Chinese parts. The output capacitor quality is critical as it is in the signal path going to the next stage. Most people replace these caps with good quality film caps. Jolida upgrades them with Clarity Caps which cost about $5 a piece. Lots of people use Obbligato Gold for this mod ($14 a piece). I chose Mundorf Supremes. They are excellent. You can spend a lot more and get "better" but the Mundorf Supreme is good. They cost $20 each and you need 2 total (one per channel). I bypassed the Mundorf, which is completely optional, with a 0.01uf Vishay Roderstein MKP 1837 film caps. They cost $1 each. I got all four caps at Parts Connexion, $42 bucks total. You can spend less or more, depending on how fancy you get.

How do they change the sound? Well, everything improved with them installed and I think the improvement was more noticeable than the Op Amp swap. The highs become more liquid and airy, details more present, sound stage better, everything gets smoother. The Mundorfs are much better than the stock junk that Jolida uses, they are also four times bigger in volume. Scan the thread and you can see how the better films caps are installed to compensate for the size difference. Make sure you know how to install them before you buy.

What are the details you need to be aware of when shopping? Shipping costs - Order as many parts are you are going to need looking across multiple project to leverage the shipping costs. Ebay Seller's - some of these guys sell used parts and some of them sell fake one. Unless the Seller is verified stick to the online retailers.

Good Luck and enjoy! Bob

PS - the biggest bang for the buck improvement are the 12AX7 tubes. I have tried many. I bought my JD9 used for $200 bucks and it came with stock Chinese tubes that were lousy. Of the new production tubes I have tried Sovtek LPS, Russian Mullard copies, Tung Sol, and Tube Store brands. I liked the Sovtek LPS and Tube Store Preferred Series 7025 the best as they seemed to be the smoothest of the bunch. The reissue Mullards were grainy, the Tung Sol too bright and forward for me.

By far NOS 12AX7's are much better. The classic ones like RCA Black Plates, Mullard, and Telefunken sound the best to me. They cost a lot. All of mine were acquired as used NOS and they still are way better than the new stuff. Tubes make the biggest impact on the sound.
 
Could someone please explain the ratings printed on the caps? The Clarity caps I currently have are 1µF / 630VDC, ESA Series. When I look at the Mundorf caps they have ratings such as 1000v, 800v, 600v, but no 630v like many others including the caps i have now. What exactly is this volt number and is it critical to match the 630v for the JD9?
 
Could someone please explain the ratings printed on the caps? The Clarity caps I currently have are 1µF / 630VDC, ESA Series. When I look at the Mundorf caps they have ratings such as 1000v, 800v, 600v, but no 630v like many others including the caps i have now. What exactly is this volt number and is it critical to match the 630v for the JD9?

The 600 volt Mundorf can replace the Clarity rated at 630 volts. The 30 volt difference is only 5% and not a issue. You can use the higher rated parts but no need to spend the extra money or waste the space.
 
Awesome response. Thanks. First thing I did years ago was swap out the stock tubes for the sovteks. I bought the op amps a couple days ago and plan on replacing them as soon as they arrive. I was going to do the caps after that but I'm not skilled at soldering. So in order to do that, I need to find someone who can remove and replace the old ones. Thanks again for the response. It was super helpful.
 
Alright! Got the opamps in and that really seemed to make a difference in the soundstage and overall noise. I soldered in the mcaps today and it sounds good but I probably should have done an A/B like I did when I installed the opamps. So I'm not sure what difference was really made. Possibly more gain? I do hear more surface noise noise right now. Is it possible that I need to adjust my dip settings now?

edit: i am using a dynavector 10x5.
 
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Alright! Got the opamps in and that really seemed to make a difference in the soundstage and overall noise. I soldered in the mcaps today and it sounds good but I probably should have done an A/B like I did when I installed the opamps. So I'm not sure what difference was really made. Possibly more gain? I do hear more surface noise noise right now. Is it possible that I need to adjust my dip settings now?

edit: i am using a dynavector 10x5.

What Mundorf caps did you use exactly? Mcaps are not Supremes. Pretty much any decent film cap will be better than the stock ones.

You should hear better clarity, it should be easier to separate instruments within the sound stage. The Supremes took a few hours to mellow out.

Adding gain does not help, it hurts. Too much gain amplifies the bad and the good, hence more surface noise, etc.

You may not hear improvement due to reasons related to limitations somewhere in the chain from stylus to the speakers to your ear.

Load for your Dynavector should be 1k ohms (switch 3 up and all other switches down)

For gain, use low output with only switch 1 up.
 
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Help needed with modded JD9 upgrade High Gain Outputs.

I've had the JD9 for 3+ years and had been using the low gain outputs for the last year or so. Recently I plugged into the high gain outputs and the sound on both L and R channels is distorted at any volume. I would describe the distortion as what I would expect from a bad ground. The high gain outputs had been previously working. I'm not an electrical type, but it looks to me like the high gain outputs are directly coupled while the low gain outputs may have an in-line cap and maybe a resistor across the + and -.

This not a major problem as the low gain outputs still sound great. However, I'd still like to fix it if not to costly. Any ideas to what could be causing the distortion?
 

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Help needed with modded JD9 upgrade High Gain Outputs.

I've had the JD9 for 3+ years and had been using the low gain outputs for the last year or so. Recently I plugged into the high gain outputs and the sound on both L and R channels is distorted at any volume. I would describe the distortion as what I would expect from a bad ground. The high gain outputs had been previously working. I'm not an electrical type, but it looks to me like the high gain outputs are directly coupled while the low gain outputs may have an in-line cap and maybe a resistor across the + and -.

This not a major problem as the low gain outputs still sound great. However, I'd still like to fix it if not to costly. Any ideas to what could be causing the distortion?

There's likely nothing wrong with the Jolida. It's probably overloading the inputs of your amplifier's preamp. I have to use the low outputs with any moving magnet cart, but can use the hi outs with a low output moving coil.
 
Help needed with modded JD9 upgrade High Gain Outputs.

I've had the JD9 for 3+ years and had been using the low gain outputs for the last year or so. Recently I plugged into the high gain outputs and the sound on both L and R channels is distorted at any volume. I would describe the distortion as what I would expect from a bad ground. The high gain outputs had been previously working. I'm not an electrical type, but it looks to me like the high gain outputs are directly coupled while the low gain outputs may have an in-line cap and maybe a resistor across the + and -.

This not a major problem as the low gain outputs still sound great. However, I'd still like to fix it if not to costly. Any ideas to what could be causing the distortion?

There may be nothing to fix. What cartridge is connected?

There is one circuit driving everything and its connected directly to the "high output" rca' s. These connections are for low output moving coil cartridges only. The minimum output with all gain switches down is 55dB, which is way too much gain for MM, MI and even LOMC.

The connectors labeled "low output" are attenuated by 20dB (by a simple voltage divider circuit) relative to high output. With all gain switches down, the "low output" has 35dB of gain, and 41 dB with switch 1 up.

These are the best settings to use for typical MM/MI cartridges.

Sounds like you were overdriving your line input? If you have a moving magnet with as 3.5mv or higher output and the gain switches up you can do some real damage. Even at the lowest gain setting you can probably cannot move your volume pot too far off of minimum.
 
What Mundorf caps did you use exactly? Mcaps are not Supremes. Pretty much any decent film cap will be better than the stock ones.

You should hear better clarity, it should be easier to separate instruments within the sound stage. The Supremes took a few hours to mellow out.

Adding gain does not help, it hurts. Too much gain amplifies the bad and the good, hence more surface noise, etc.

You may not hear improvement due to reasons related to limitations somewhere in the chain from stylus to the speakers to your ear.

Load for your Dynavector should be 1k ohms (switch 3 up and all other switches down)

For gain, use low output with only switch 1 up.
Awesome! Thanks. Switching switch one instead of two should do it. I used Mcap supreme. When I added the opamps I heard a much more dynamic and detailed soundstage and was really impressed. When I added the new caps I felt like I got more bloated bass and more fatigue because of increased gain. Am I crazy? I still am not really sure how the caps affect the sound.
 
Awesome! Thanks. Switching switch one instead of two should do it. I used Mcap supreme. When I added the opamps I heard a much more dynamic and detailed soundstage and was really impressed. When I added the new caps I felt like I got more bloated bass and more fatigue because of increased gain. Am I crazy? I still am not really sure how the caps affect the sound.
Here are some photos of what I've got going on here. Sorry for the blurry photos. I've very unsteady hands.
 

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Here are some photos of what I've got going on here. Sorry for the blurry photos. I've very unsteady hands.
You removed the old caps correct?

The Mundorf Supremes should be a noticeable improvement for sure. Sometimes it pays to take your time and really know your sound and what you are trying to achieve. Listen to it as is for a few weeks, I'll bet if you put the old caps back you would notice the degrade.

For now just chill and enjoy. If you have some Blu Tac you can use it to hold your caps in place and keep them from vibrations. Just set them in a bed of Blu Tac and roll some up the sides to hold the body of the cap in place.

In a few weeks you might want to try bypassing the Mundorf with a nice 0.01uf MKP 1837. For now let it break in and enjoy.

What tubes do you have in there?
 
There's likely nothing wrong with the Jolida. It's probably overloading the inputs of your amplifier's preamp. I have to use the low outputs with any moving magnet cart, but can use the hi outs with a low output moving coil.

Thanks for the reply. You're probably right. Spoke to Patrick at Needle Doctor earlier and he said the same thing. I was also using a different preamp earlier and he said the one I'm using now is pretty sensitive to overloading.
 
I've g
You removed the old caps correct?

The Mundorf Supremes should be a noticeable improvement for sure. Sometimes it pays to take your time and really know your sound and what you are trying to achieve. Listen to it as is for a few weeks, I'll bet if you put the old caps back you would notice the degrade.

For now just chill and enjoy. If you have some Blu Tac you can use it to hold your caps in place and keep them from vibrations. Just set them in a bed of Blu Tac and roll some up the sides to hold the body of the cap in place.

In a few weeks you might want to try bypassing the Mundorf with a nice 0.01uf MKP 1837. For now let it break in and enjoy.

What tubes do you have in there?

I've got sovtek 12ax7s in there now. Thanks for the advice.
 
There may be nothing to fix. What cartridge is connected?

There is one circuit driving everything and its connected directly to the "high output" rca' s. These connections are for low output moving coil cartridges only. The minimum output with all gain switches down is 55dB, which is way too much gain for MM, MI and even LOMC.

The connectors labeled "low output" are attenuated by 20dB (by a simple voltage divider circuit) relative to high output. With all gain switches down, the "low output" has 35dB of gain, and 41 dB with switch 1 up.

These are the best settings to use for typical MM/MI cartridges.

Sounds like you were overdriving your line input? If you have a moving magnet with as 3.5mv or higher output and the gain switches up you can do some real damage. Even at the lowest gain setting you can probably cannot move your volume pot too far off of minimum.

Thanks for the reply. I'm using a Grado MI with an output of 1 mV. As I mentioned above, Patrick at Needle Doctor said the same thing - that I was likely over driving the pre-amp.

BTW did you ever try the Northern Electric 12ax7 from the tube store? I have and I like them (and nos GE 5 star 5751's) a lot in my modded JD9 upgrade. I also tried nos Mullard 12ax7 and JAN-GE 12ax7wa's and didn't like them as well. The JD9 upgrade came with Tungsol 12ax7 and I don't care for them much at all.

Thanks again!
 
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