Jolida JD9 phono amp hybrid Magic...

brianhiatt · « **Reply #100 on:** 3 Mar 2011, 06:35 pm »

Hello all,

So this thread really helped me, it's amazing the difference in sound, I love it and wanted to tell all of you thank you!

Based on this thread, I made a few of the changes and wanted to report out just in case it helps anyone else. I don't know what change made the most difference and don't care because the unit is now substantially better sounding to me in every way.

I have not touched the op-amps but I really want to. I just have a money restriction.

The things I decided to change:
1. Replaced the 100 UF cap's
* These are for the output from the tubes
* used the Obligatos
2. Replaced the 97 pf cap's
* These are for the 100 ohm setting of the input board
* SILVER MICA was used
* No issues soldering to the board, seemed easy enough to me
3. Replaced the resistors for my appropriate for my cartridge:
* replace with Visay naked Z
* I got the 470R and my output is a bit low but I was able to increase the output on my preamp so it worked out fine.
* again, no issues soldering to the board, seemed easy enough to me
4. rewired most of the internal signal cables
* direct soldered to the boards, replacing mechanical connections.
* Used kimber cable that I had hanging around from a pair of old audio interconnects.
* from the output to the RCA jacks I used blue jeans cable (I really like this stuff)

Here is exacatly what I bought from parts connexion: (not endorsing them but they met my needs)
* 2 Vishay Resistor_ 470R Vishay VAR-Series "naked" Z201 Z-FOIL RESISTOR 1%
* 2 Obligatto Film Cap 1.0uF / 630V, Premium Gold Film Cap
* 2 SILVER MICA 91pf 500V CAPACITOR
* WBT solder (just buy it or any high quality silver bearing solder) It's worth 5 times what it costs, take my word for it please, do you self a favor...

Don't know if I did it all "right" but it sure sounds massively better.

Two pictures:
First shows the overview of the cap replacement and the hard wire of the channels
(important note, these replaced the original caps that I took out from the other side of the board)

Second shows the resistors, creepy looking Naked Z, and the silver mica caps...

kyrill · « **Reply #101 on:** 7 Mar 2011, 11:08 am »

Thank you Undertow for beginning this thread, because of it and all the nice contributions

I bought a new JD9 ( JD-9A does not really exist, they are all JD9 factory wise)

After reading all 6 pages and http://www.diyaudio.com/forums/analog-line-level/177243-jolida-jd9-upgrade-mods-clarification.html, I am planning to do what brianhiatt did and others and also will replace the 6 OP37G

BUT, what struck me already from your posts and others when replacing the opamps, as well in in the DIY forums, you replace one opamp for another better opamp.

I have replaced the 6 opamps ( ah well Doug of Asi-Tek.com did it) in the I/V stage and and analogue output stage of my beloved DEQX pre-amp with discrete opamp drop in replacement of Burson Audio. The same ones or similar to what Burson Audio uses in their highly praised HA160D DAC ( http://6moons.com/audioreviews/burson5/4.html)

So I will order 6 OP37G replacements from Burson Audio as they really showed with their DAC and head amp they make wonderful HD opamps discrete replacements

Brett a · « **Reply #102 on:** 7 Mar 2011, 09:23 pm »

Thanks everyone so far. This is all getting me excited to do some of these mods.

Quote from: Doronor on 30 Nov 2010, 06:14 am

(...)
The best overall cap in our mind is the AMP OHM Polyester in Oil Aluminum Foil.
(...)

I wonder if someone could clarify what would be the best AMP OHM cap to use since the poly seems to be no longer available. Would it be best to get Paper in Oil/Aluminium Foil or Paper in Oil/Tin Foil?

Looking forward. Thanks again to all so far.

doug s. · « **Reply #103 on:** 8 Mar 2011, 06:46 pm »

another option to the burson discrete opamps is this:

http://www.audio-gd.com/Pro/diy/OPA/OPAEN.htm

these folks actually made the original burson opamps; these are about 30-40% the price of those offered by burson...

doug s.

kyrill · « **Reply #104 on:** 8 Mar 2011, 06:57 pm »

thx Doug
I hope Burson have refined and or further developed them, if your source brought the truth

doug s. · « **Reply #105 on:** 8 Mar 2011, 07:02 pm »

Quote from: kyrill on 8 Mar 2011, 06:57 pm

thx Doug
I hope Burson have refined and or further developed them, if your source brought the truth

yes, they have, but so has audio-gd - the earth is basically the original burson; their sun & moon are further developed...

doug s.

kyrill · « **Reply #106 on:** 8 Mar 2011, 07:24 pm »

I have ordered my Jolida direct in China
except from my Paypal paid confirmation 3 days ago, i have not heard from them (yet)

I am convinced the JD-9 can be made in a world class pre-pre amp

bigdirty · « **Reply #107 on:** 5 Apr 2011, 03:48 am »

Quote from: kyrill on 7 Mar 2011, 11:08 am

So I will order 6 OP37G replacements from Burson Audio as they really showed with their DAC and head amp they make wonderful HD opamps discrete replacements

you should only need 2, for the output. The others are only 5v and not enough power for the bursons or audioGD. The audioGD looking for 9 - 25v

Doronor · « **Reply #108 on:** 5 Apr 2011, 04:43 am »

So here is a challenge boys and girls:
Did any of you brave Jolida JD-9 owners try to bypass the high gain resistor altogether (bridge it with a wire instead of a resistor that is)?
I am referring to those with ultra low gain cartridges (Dynavector MC Rubby for instance) who needed step-up transformer to get the proper gain, even with the highest gain settings in the Jolida.
I just thought that less is more and the best resistor is no resistor, which can potentially allow to get rid of the step-up transformer as well (two birds with one rock).

Any thoughts?

Thanks for your input.

Happy listening.

kyrill · « **Reply #109 on:** 5 Apr 2011, 07:14 am »

OH BIGDIRTY
that is not good news. So I have to make a seprate pws for all of them ( I have already ordered 6 and received them.)

Are you sure? Why would "Jolida" power 6 same opamps with different voltages?

Doronor · « **Reply #110 on:** 5 Apr 2011, 01:11 pm »

Kyrill,

I can buy a pair or two from you, if you do not need them all but need to understand how it worked out for you as my attempt to change any of these op- amps to even AD843KN or the Burr Brown ended up with utter failure (the AD added noise without benefit and the Burr Brown made a high pitch "TV like" noise and nothing else). Trying to put only two did not really bring anything to table for me and my friends (we all use Dynavector low output Karat 17D3 and Rubby = highest gain settings and NO capacitance loading).

What load settings are you using?

bigdirty · « **Reply #111 on:** 5 Apr 2011, 01:42 pm »

Quote from: kyrill on 5 Apr 2011, 07:14 am

OH BIGDIRTY
that is not good news. So I have to make a seprate pws for all of them ( I have already ordered 6 and received them.)

Are you sure? Why would "Jolida" power 6 same opamps with different voltages?

next time your inside your JD9 have a look. The transformer is outputting 16-0-16v. regulated to 15v for the output buffer/amp. Its then regulated again, twice, to 5v for the RIAA filter.

Quote from: Doronor on 5 Apr 2011, 04:43 am

So here is a challenge boys and girls:
Did any of you brave Jolida JD-9 owners try to bypass the high gain resistor altogether (bridge it with a wire instead of a resistor that is)?
I am referring to those with ultra low gain cartridges (Dynavector MC Rubby for instance) who needed step-up transformer to get the proper gain, even with the highest gain settings in the Jolida.
I just thought that less is more and the best resistor is no resistor, which can potentially allow to get rid of the step-up transformer as well (two birds with one rock).

Any thoughts?

Thanks for your input.

Happy listening.

Doron, have you tried just flipping all three switches to the off position?

edit: reread your post. flipping all three gain switches off leads to lower gain.

kyrill · « **Reply #112 on:** 5 Apr 2011, 02:05 pm »

I even have not my Jolida yet

For some unknown reason they could ship a 5 weeks after ( so next week!) I paid and ordered, so the factory does not have them at stock?

Hi Doronor

That willl take some time. I am a purist, so i will try to find out first how to use all the Burson opamps. If necessary i will build a A123 26650 Lifepo4 battery rig to power all those opamps the better the power for a pre-preamp the more effective for the whole chain afterwards

Doronor · « **Reply #113 on:** 6 Apr 2011, 01:51 am »

Bigdirty,
If you look at the back view, the right hand side switch controls the high output so it is in the "on" position (up position). It still goes through low resistance resistor, hence high gain.
Are you claiming that switching all of them to "off" (down position) and using the high output rca's will yield by-passing the resistor altogether?

Thanks,

Doron

bigdirty · « **Reply #114 on:** 6 Apr 2011, 02:11 am »

Quote from: Doronor on 6 Apr 2011, 01:51 am

Bigdirty,
If you look at the back view, the right hand side switch controls the high output so it is in the "on" position (up position). It still goes through low resistance resistor, hence high gain.
Are you claiming that switching all of them to "off" (down position) and using the high output rca's will yield by-passing the resistor altogether?

Thanks,

Doron

Doron,

Im a bit confused by your comments. The Switches have nothing to do with the output rca's. When I switch from using the MM gain setting (1k resistor) to all switches off I get lower volume.

Doronor · « **Reply #115 on:** 6 Apr 2011, 05:41 am »

Bigdirty,

My loading setting (capacitance and impedance are all OFF as I find this works best for my Dynavector 17D3).
When I use the right hand side dip-switch from the three dip-switches:

and use the right hand side output RCA's (the high gain ones), I believe this is the highest gain settings.
Are you claiming that putting all three dip-switches on "off" will increase the gain (bypass the resistor)?
I though putting them all in "off" will not output any signal.
Now assuming we are on the same page, my question is if anyone tried to by-pass the resistor behind the right hand side dip-switch (which dictates the gain - the lower it is, the higher the gain)?
By by-passing the high gain resistor I mean - use a bear wire instead of a resistor so the connection is there but without the resistance (or with negligibile resistance that is).
Like in the following photo:

Thanks,

Doron

robob · « **Reply #116 on:** 21 Apr 2011, 09:33 pm »

Hey Folks,

Been on others, new to this one. Happy to be here.

I have a JD9 that is close to a month old. Put in Sylvania NOS 80's 5751's that are better than the original Tung Sol 12ax7's in terms of detail and refinement. I am still getting a pronounced midrange peak that I would say is in the 1k-2.5k range. Very noticeable on some of my jazz lp's. Otherwise I really like the JD9. My other main phone pre is a GCPH which has more upper highs and is more detailed but I does not have the warmth of the JD9. The JD9 is not flabby but does have a nice warmth to it and maybe more slam than the GCPH.

So, my dealer is willing to help mod it and we want to know what mod(s) would we do to specifically get rid of the midrange peak?

Thanks,
Robert A. Oberj
PS: Cart is a Lyra Kleos on an SME 309 with the stock VDH cable. The 309 is mounted on a newly refurb Sota Star with some upgrades.

robob · « **Reply #117 on:** 24 Apr 2011, 06:01 pm »

So nobody has either experienced the midrange peak or otherwise has an idea to get rid of it?

Thanks,
Robert

bigdirty · « **Reply #118 on:** 1 May 2011, 03:05 pm »

Quote from: robob on 24 Apr 2011, 06:01 pm

So nobody has either experienced the midrange peak or otherwise has an idea to get rid of it?

Thanks,
Robert

have you tried playing with the loading caps and resistors?

linked from another forum and not verified.

robob · « **Reply #119 on:** 1 May 2011, 06:55 pm »

have you tried playing with the loading caps and resistors?

If you mean replacing them, I have not. I do have the Dip Switch chart and currently am at 230 for my Kleos. I have even tried a few different capacitance setings.

On further listening, it sounds more like an elevated shelf from about 1k to maybe 5k or so. Even with the 5751's it does not have the output on the very top of my GCPH but I can live with that for now. As my room and ears are sensitive to peaky mids and lower treble, this is annoying.

Thanks for your reply,
Robert