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Quick review of my modded Jolida JD9 and some advice

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Quick review of my modded Jolida JD9 and some advice

Postby asheetan » 12 May 2013 06:40

I few days ago I upgraded the caps in my JD9 MKII to Obbligato Gold and that made a good bit of difference in the sound. The instruments had a lot more air around them, the imaging and instrument placement improved a lot and the soundstage became wider. The music was crisp and warm, not bright at all. Vocals improved in depth so I was happy with the upgrade. I had also ordered the Golden Dragon tube rings by Duende Criatura. From what I read they were supposed to help improve the imaging and the instrument placement. Well not so, at least not in my case. If anything they dampened the sound. The music sounded choked and restricted. Not what I had expected. Well that was a disappointment. Off they came and on came the metal tube covers. Things sounded better, back to what it sounded when I first modified the pre. Then I took the metal tube covers off and ran naked (the tubes not I. That would be a very scary sight if I did) and boy did that improve things. A lot more air, things opened quite a bit. I never though dampers and covers could make such a difference. Oh well, live and learn.

Ah, but the biggest surprise of all came when I installed those small Bluish 0.01uF Vishay caps as a bypass. I was very skeptical at first, I mean what could a 0.01uF cap possibly do, but boy o boy did they improve things. Everything became so clear, crisp and resonating. In short it was amazing. They cleaned things up to a point that I could actually hear the Sax player blowing in his horn.. I could almost see the base guitar strings vibrate.. Yep that good.

Now I have couple of questions for the JD9 mod veterans. I am considering changing the load resistors, just the 100 ones. I hear they make a difference. Only problem is they are so darn small and my hands are shaky (that should prove to be very interesting). Anyway what would you guys suggest and for those who have changed them, do they make a noticeable difference? In other words is it worth the trouble and possibly burning down the house?

My second question is about tubes. I would like to change the stock Tunsol tubes with the following:
Tungsol Gold Pins
Gold Lion
TJ Full Music
What are your thoughts? Anyone tried the TJ Full Music? I would appreciate any and all input regarding the above three choices. I am not necessarily married to those three choices but at this point in time they are the ones I am considering.

Thanks
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Re: Quick review of my modded Jolida JD9 and some advice

Postby yellowbuses » 12 May 2013 08:34

Two things I find invaluable when doing pcb work with fine, intricate components is a small bench vice as used by model maker enthusiasts and some blue tack which is especially useful when inserting a components legs. It can be easily removed after soldering. I also usually heat-sink with a crocodile clip though that is not always possible.

As to component changes, all very subjective but I would head over to DIY Audio and you may find some specific recommendations.

Hope that helps.

regards
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Re: Quick review of my modded Jolida JD9 and some advice

Postby jjrenman » 12 May 2013 19:22

I recently experimented with load resistors to see what diff it can make if any. I was a bit surprised that it did reveal more low level detail when switching to a very good metal film. FWIW, I'd suggest that you continue your mods in other areas first as my gut tells me that the loading resistors are not yet your weakest link. Also I'd target the op amps. check out the Burr Brown OPA 627's. Then I'd roll the tubes.
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Re: Quick review of my modded Jolida JD9 and some advice

Postby asheetan » 13 May 2013 00:11

jjrenman wrote:Also I'd target the op amps. check out the Burr Brown OPA 627's. Then I'd roll the tubes.

Actually the Burr Brown OPAs are on my upgrade list but I was saving them for last. I guess it would not hurt to go ahead and do them. A question though; there are the Burr Brown OPA 627's and 637’s not sure of the difference and which is better for the JD9? I am guessing the 627AP and not the 627AU not sure about that either. Since I will be ordering the Opamps I might as well order tubes to go with them but not sure which ones yet.. And how much more can the JD9 be upgrade? I mean how much better sounding can it get? The one mod I did for it already made a big difference. Don’t get me wrong I am digging this, it will keep me busy for a little while and it is fun. I am also planning on trying the super cap by Hovland as per your recommendation in a couple of months or so. Can’t let that soldering iron get too cold.. Again thank you for your input.

yellowbuses wrote:As to component changes, all very subjective but I would head over to DIY Audio and you may find some specific recommendations.

Hope that helps.

regards

Thanks. Everything helps; sometimes small tips make a huge difference. I never knew about blue tack but now I do.. I looked at the DIY Audio but have not joined yet. I am not big on forums and this forum is the second one I am a member of and the one I frequent the most, at least lately.. But I guess it will not hurt to join the DIY Audio. Lord knows I need all the advice I can get.

Cheers
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Re: Quick review of my modded Jolida JD9 and some advice

Postby jjrenman » 13 May 2013 02:08

Check out this article on op amps. It should answer a lot of your questions. I use to roll a lot of op amps before I replaced them with tube circuits. I have tried a lot of the same op amps and agree with the nearly all of the testers comments.

http://tangentsoft.net/audio/opamps.html

To your question of how far you can go with upgrades, IMO, that will be when you reach the limits of the op amps that you are using. In this case I'd start with the coupling caps as you have done, then change out the op amps which then will let you hear bigger diffs when you do some tube rolling. After that I'd change the loading resistors. At this point it would be a lot more work for smaller diffs but IME it would probably be the power supply caps to the op amps.
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Re: Quick review of my modded Jolida JD9 and some advice

Postby asheetan » 14 May 2013 03:10

Hello jjrenman,

Thanks for the info and the link. It answered my questions and educated me about a lot of things. I decided on the Burr Brown OPA 627's. As for the other mods, I think I will stop at changing the loading resistors if I decide to change them since I know they will prove to be a challenge for my shaky hands especially those tiny 100 ones.

Once again thank you for all your advice, information and help.

Cheers
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Re: Quick review of my modded Jolida JD9 and some advice

Postby dolsey01 » 14 May 2013 15:04

Please post comments back when you do the opamps. That and the cap upgrade are next on my list. I've done a few tube rolls after listening to the stock Tung-Sols, I first went with some EH 12AX7s which brought back what I felt was a recessed midrange in the Tung-Sols but seemed less dynamic and then to NOS 1970s Sylvania 5751s which have a really rich midrange and were my favorite out of the three. Even with the 5751s the JD9 has too much gain with my 5mv Grado Sonata so I just bought a matched pair of NOS Sylvania 1964 JAN-5814A (12AU7 equivalent) which seem to have the great midrange of the 5751s I had while lowering the output enough that I get a decent range in my volume control now.
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Re: Quick review of my modded Jolida JD9 and some advice

Postby Guest » 14 May 2013 17:33

jjrenman wrote:Check out this article on op amps. It should answer a lot of your questions. I use to roll a lot of op amps before I replaced them with tube circuits. I have tried a lot of the same op amps and agree with the nearly all of the testers comments.

http://tangentsoft.net/audio/opamps.html

To your question of how far you can go with upgrades, IMO, that will be when you reach the limits of the op amps that you are using. In this case I'd start with the coupling caps as you have done, then change out the op amps which then will let you hear bigger diffs when you do some tube rolling. After that I'd change the loading resistors. At this point it would be a lot more work for smaller diffs but IME it would probably be the power supply caps to the op amps.


I didn't really understand the point of that article. The guy seems to be outputing a particular voltage across a particular load, and then lowering the power supply voltage until clipping occurs. Different op-amps clip with different power supply voltages. What is that information meant to reveal? It may be relevent for headphone amplifiers but I wouldn't use it as a general guide to the op-amp's performance in more normal use. The way an amp performs into 33 ohms could well be very different to way it performs into 10k or 100k.
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Re: Quick review of my modded Jolida JD9 and some advice

Postby jjrenman » 14 May 2013 19:53

The reason that I referred to the "article" is that the reviewers comments about sound quality are consistent with my experiences when trying many different op amps in both headphone circuits, op amp CD outputs as well as op amp based phono preamps.

I did not go into greater detail because I assumed that the OP will only be considering op amps that have been tried and recommended by fellow Jolida JD9 owners.
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Re: Quick review of my modded Jolida JD9 and some advice

Postby jjrenman » 14 May 2013 19:58

to "asheetan", I assume that when you are ready to change out the op amps that you will be soldering in IC sockets to accept the op amps without having to solder them into place.

Also, use some kind of heat sink on the legs of the resistors if they are metal film so that when you solder them in you do not melt the metal film inside the ressitor.
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Re: Quick review of my modded Jolida JD9 and some advice

Postby asheetan » 15 May 2013 02:37

dolsey01 wrote:Please post comments back when you do the opamps.

Will do. I don’t think the Jolida JD9 cares if you use high output or low output or anything in between where the gain is concerned. I was running a Grado Platinum 1 with 5mv output and then switched to a Dynavector 20X2 Low output 0.3mv and did not notice any drop in the gain.. I tried the high MC gain setting (the middle one). It dropped the gain a bit but sounded stifled so went back to the low MC gain setting and never looked back. I like the JD9 gain, can’t have enough gain, kinda like horsepower can’t have enough of that either. Of course I have not been able to turn the volume past 9 o’clock. I’ll either get evicted or would have to repaint the walls. :D
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Re: Quick review of my modded Jolida JD9 and some advice

Postby asheetan » 15 May 2013 02:39

jjrenman wrote:to "asheetan", I assume that when you are ready to change out the op amps that you will be soldering in IC sockets to accept the op amps without having to solder them into place.

Soldering in IC sockets for the 627s? Don’t scare me like that. I just ordered the 627AP; they come in the DIP flavor. They are supposed to simply plug in the sockets where the stock ones sit. HELP! Somebody please tell me there is no soldering involved.. lol Or could it be I was mistaken? Nah can’t be, I hate soldering minute things. I guess I’ll find out when I get them. Oh well..

At any rate I am looking at the 12AX7 Psvane GF T-Collection Vacuum Tubes. Has anyone tried them? They seem to be on par with TJ Full Music and in a number of reviews; the reviewers preferred them to the TJ Full Music. The tubes will be the last investment I’ll put in the JD9 for a while so I want to make sure I get decent ones.

One more question. If I turn on the JD9 and leave it on without playing records or anything, just sitting there turned on, would that burn the tubes in? Ah grasshopper much to learn..
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Re: Quick review of my modded Jolida JD9 and some advice

Postby jjrenman » 15 May 2013 19:27

I apologize for the scare. The JD9 could very well have the op amp sockets already installed. My experience comes from modifying op amp based phono stages that have the op amps soldered into the PCB so the first thing I'd do is solder the op amp sockets.....

I've tried the 12AX7 Psvane's in my SET amp and was very impressed for a current production tube.

As far as burn in goes IME as well as the general consensus is that you will need to play music through it.
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Re: Quick review of my modded Jolida JD9 and some advice

Postby asheetan » 18 May 2013 21:08

The OPA 627’s arrived yesterday and needless to say they were in the JD9 within 15 minutes. YEAH no soldering; they simply plug in the IC sockets.. SWEET!. However, if you are going to change them be careful when you install them. The legs are delicate and if you don’t have them perfectly aligned with the sockets you could easily mangle them, kind like I did with one of them and then had to very carefully and very gently un-mangle them. That happens you can easily break off a leg so to speak..lol It seems that I always have to have an adventure with anything I do, like the shelves I built for my classical collection, Jazz collection, box sets etc.. only to find out that I used the wrong stain, so here we go again, sanding and re-staining.. And here’s the kicker I am not exactly known for my patience. Oh and I am old enough that It is virtually impossible for me to learn patience..

Now the review of the Burr Brown or I should say TI OPA627’s. I was not really expecting too much of an improvement simply because some of the reviews state that Op amps don’t make much of a difference and that the BR 627’s are no exception. To those reviewers I would have to say that either they are going by what they read somewhere and never compared the 627’s themselves or there is something wrong with their equipment or, hate to say it, there is something wrong with their ears..

Well to put it simply the OPA627’s made a huge difference, in my case I think they made the most improvement yet. The background is quitter, blacker, and a lot clearer. The mids are more liquid and pronounced. The lows and highs are a lot more extended. The symbols shimmer a lot more and are much clearer. The drum brushes now sound a lot more like drum brushes as opposed to a slushing sound. The Base gained a bit more slam and became rounder. But here’s where the 627’s shine; the separation of instruments. The imaging and separation of instruments is amazing. I was listening to Stan Getz’s Jazz Samba Encore which I have listened to hundreds of times. In one of the tracks (incidentally that album has one of the best channel separation recordings I have heard) and on the right channel there is a segment of a piano and guitar being played. Now before I installed the 627’s I could hear the guitar and the piano playing together and the imaging was fine too but when I listen to it after I installed the 627’s I could actually hear the guitar being played in front of the piano and a little to the right. I have never heard that before. You can actually visualize the guitar player standing a few of feet in front of the piano and a little to right playing the guitar. That’s how good the separation of instruments became. So much air around the instruments now it is almost orga.. (I don’t know if I can use this word here but you get my drift). In a sense it made the Jolida seem to have more gain (like it needs it). Now moving on to classical music. The violins and the instruments are now a group of individual instruments of the orchestra as opposed to a big mass of instruments.

As much as I liked the Jolida’s sound before installing the 627’s, I always felt that there was a little something missing. The opa 627’s fixed all that and brought everything the Jolida has to offer together. Now I am hearing layers upon layers of instruments and music and hearing things that went missing without the separation the 627’s brought. I also seem to have lost control of my feet; they seem to have developed mind of their own and start tapping on their own whenever they hear music.

All of that and I am still using the inferior stock tubes that came with the Jolida. Not to worry the Psvane 12AX7-T tubes are on the way. Can’t wait to roll those. After that I’ll change the load resistor and then the WORLD Pinky.. The world..

In short the Burrs are purring in my Jolida.. Burr.. Purr.. Purr.. Purr.. Good kitty..

jjrenman wrote:FWIW, I'd suggest that you continue your mods in other areas first as my gut tells me that the loading resistors are not yet your weakest link. Also I'd target the op amps. check out the Burr Brown OPA 627's. Then I'd roll the tubes.

Jjrenman, you were so right about the weakest link. Thank you for opening my eyes about the 627’s and the info you provided.

Cheers
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Re: Quick review of my modded Jolida JD9 and some advice

Postby dolsey01 » 18 May 2013 22:00

Great, sounds like I'm about to become $120 poorer! :)
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