Official Jolida JD9 thread

Do you think the mods made a huge difference or just bring out some of the more subtle sounds?

The mods are worth it. Dynamic mids, highs that sparkle and bass with authority. Start with the opamps, then work on the loading board and finish it off with the output caps IMO.

big
 
I'm also impressed with this phono stage, I'm using it with a AT-155lc cartridge. I upgraded the tubes with Tungsram ecc83's. They are a clear improvement, tough the stock tubes aren't bad at all!
 
Bump with some pics of my modified JD9.

Im using AD843KN in the output, op627 in the middle and LT1028 in the right op sockets. Ampohm output caps. Tantalum resistors and silver mica in the loading board. Amtrans carbon film resistor in series with the valve input. Cree Silicon Carbide Schottky Diodes in the power supply.

What fun :music:

I think you've got it. This is probably the optimum OP amp configuration for the Jolida. I have some AD843 KN on my box, too. so next I will try them in the output stage and put the OP627 in the middle stage. I love the LT1028 in the input stage because of their quietness.
 
I think you've got it. This is probably the optimum OP amp configuration for the Jolida. I have some AD843 KN on my box, too. so next I will try them in the output stage and put the OP627 in the middle stage. I love the LT1028 in the input stage because of their quietness.

Since landing on this combo, Ive found some of my less than stellar recordings are much easier on the ears. AND, and that is a big and, it seems like I can turn my volume up higher without fatigue. :banana: sorry neighbors haha.

big
 
Bump with some pics of my modified JD9.

Im using AD843KN in the output, op627 in the middle and LT1028 in the right op sockets. Ampohm output caps. Tantalum resistors and silver mica in the loading board. Amtrans carbon film resistor in series with the valve input. Cree Silicon Carbide Schottky Diodes in the power supply.

What fun :music:


Thanks... Great post!

What tubes have you settled on ?

My next step is swapping-out the op amps. My unit already has 'upgraded' caps, resistors & diodes done by Underwood HiFi. They were done before I bought my JD9 2nd hand.

*Caution* Did you guys know that Underwood HiFi suggests rolling 12au7/ecc82 tubes along with 12ax7/ecc83 ones to find the 'right ones' for your personal taste!?

Personally I've tried RFT ecc82... Not bad and they tone down the highs when using a MM cart from the "High Output" connection. I didnt run them too long because I was told by online gurus that the 12au7 could or would overload the plates and cause problems or even unit failure. :scratch2:

I'm not so sure. THOUGHTS???
 
Thanks... Great post!
What tubes have you settled on ?


Right now Im running new production Tung Sol. Havnt tried anything else. Im interested in the Psvane and the Genalex.

I thought about using 12au7 to tame some of the gain of the 12ax7, but have the same reservations about overloading the plates. Im sure it would be as simple as changing some of the values of the resistors around the tubes. Thats a bit beyond me though.

maybe some AK tube gurus could chime in on this subject?

big
 
Right now Im running new production Tung Sol. Havnt tried anything else. Im interested in the Psvane and the Genalex.


My experience with Genalex/Gold Lion ECC83/12AX7:

The higher the output of the cart the better the Gold Lion sounds w/JD9

Really nice with my KAB/Ortofon ProS40 4.0mV

Ok with my AT15/20ss 2.7mV

Not so good with my DL-160 1.6mV (some say it is a bit higher)

Forget it with both my Denon 103 & DL-S1

BTW- the KAB SL-1200 + Dynavector P-75II + Denon DL-S1 is :music: (thanks to several AKers & AAers for leading me to that combo) :thmbsp:
 
*Caution* Did you guys know that Underwood HiFi suggests rolling 12au7/ecc82 tubes along with 12ax7/ecc83 ones to find the 'right ones' for your personal taste!?


I thought about using 12au7 to tame some of the gain of the 12ax7, but have the same reservations about overloading the plates. Im sure it would be as simple as changing some of the values of the resistors around the tubes. Thats a bit beyond me though.

maybe some AK tube gurus could chime in on this subject?


I would like to re-hear some thoughts & ideas about this too...
 
Which caps?

Well, I'm ready to begin my upgrades with new output caps. I've read the very comprehensive thread over on Audio Circle as well as this one and find myself in need of guidance in selecting the best caps for me.

I'm looking at Ampohms or Obbligato Gold Premium. From what I have read, it seems between these two, the Ampohms are the better performers. The Obbs have been reported as shy on bass which I can't afford in my current system.

But if i go with Ampohms, what variety do i get? Paper in oil with tin? or paper in oil with aluminum? I see the ones with tin are almost twice the price I figure this must be because they are the ones I want.

BTW, the Ampohms with tin would be about as far as I'd want to stretch my budget (@$60/pr) and would be happy to buy something less expensive if that wasn't "pound foolish"
 
I'm looking at Ampohms or Obbligato Gold Premium. From what I have read, it seems between these two, the Ampohms are the better performers. The Obbs have been reported as shy on bass which I can't afford in my current system.

In my JD9 I have had both the ampohm pio/tin and obbligato gold, as well as mundorf supreme. I prefer the sound of the ampohm in my system. solid bass, sweet mid range, yada yada.

If you go with the obbligato, the money saved could be put toward opamps. In my system with obbligato caps, I found AD843kn in the output spot and LT1028 at the input really brought the obbligato caps to life. crystal clear highs and tight bass.

The JD9 is a terrific playground isnt it? have fun :music:

big
 
Another JD-9a owner here. Running A Supex MC on medium gain setting, 100 ohms loading. I'm using the "hi-out" to a passive pre. So far I've removed the tube shields and exposed a pair of new issue Tung-Sols. Sounds pretty good! so far. I don't find it very quiet though.
 
I've removed the tube shields and exposed a pair of new issue Tung-Sols. Sounds pretty good! so far. I don't find it very quiet though.
Is that to say you found that your came stock with Tung-Sols? I was surprised to see mine came stock with a pair of Electro Harmonix. Mine is a Maryland unit BTW.
 
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In my JD9 I have had both the ampohm pio/tin and obbligato gold, as well as mundorf supreme. I prefer the sound of the ampohm in my system. solid bass, sweet mid range, yada yada.

If you go with the obbligato, the money saved could be put toward opamps. In my system with obbligato caps, I found AD843kn in the output spot and LT1028 at the input really brought the obbligato caps to life. crystal clear highs and tight bass.

The JD9 is a terrific playground isnt it? have fun :music:

big

Thanks for the info. I see you went with the tin Ampohms. Is that necessary, or are the aluminum ones a viable option?
 
Thanks... Great post!

*Caution* Did you guys know that Underwood HiFi suggests rolling 12au7/ecc82 tubes along with 12ax7/ecc83 ones to find the 'right ones' for your personal taste!?

Personally I've tried RFT ecc82... Not bad and they tone down the highs when using a MM cart from the "High Output" connection. I didnt run them too long because I was told by online gurus that the 12au7 could or would overload the plates and cause problems or even unit failure. :scratch2:

I'm not so sure. THOUGHTS???

I am not sure Frank's question above ever got answered (if there is an answer). I too am rolling 12AU7s and AT7s in my JD9 and think they greatly improve the quality of sound...and plan on continuing the practice.

Please ....thoughts?
 
I am not sure Frank's question above ever got answered (if there is an answer). I too am rolling 12AU7s and AT7s in my JD9 and think they greatly improve the quality of sound...and plan on continuing the practice.

Please ....thoughts?

I'm not sure about 12AU7s, but someone here told me a long time ago that the 5751 tube - commonly substituted for 12AX7 - will throw off the RIAA curve in a phono stage. Anyone know if this is the case with 12AU7 tubes in place of 12AX7 in a phono preamp?

It's too bad because I've found 5751 tubes are the best in my Jolida CD player, but they're not appropriate for the JD-9, technically speaking.
 
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