Jolida JD9 II - Unique Question.

[jhaan92]

Been a very long time since I had the time to look at threads, let alone even post here on AK.

Those that know me have read the Ohm Walsh 2 Recap thread, with several people telling me that thread is a benchmark when it comes to the inner workings of the Walsh 2 loudspeaker. For the record, after the caps broke in, they sounded downright incredible - but they still need a subwoofer! Guess you can't outrun the physical limitations of the driver.

Anyways, I digress...

I was able to borrow a Jolida JD9 II with the upgrade 1 package (clarity caps and gold pin Tung Sol 12AX7 tubes) from our local Needle Doctor...without a blood sample, fingerprint, or first born child!

I hooked everything up (including proper setting of the DIP switches) and let it warm up for a couple of minutes before proceeding to enjoy it. The first 15 minutes were pure nirvana. Everything was where it should be. I was extremely pleased...initally.

After that, I began to notice a change in tonality. The high frequency started to sound dulled. I thought that I was suffering from listener fatigue at first, so I walked away for a little bit to relax my ears. I was listening to the MOFI pressing of Marc Cohn, which has incredible sound staging and piano work when I started listening to the Jolida.

However, listener fatigue was not the case. After my ear break, I started the album over, and the piano sounded dull and lifeless, sounding like a sheet had been placed over both speakers. So, feeling disgusted, I powered down the Jolida, and listened to some streaming music for an hour or so.

Decided to give the Jolida another whirl, and the sound I first heard was back...for about 15 minutes. So, I am pretty confident that it is with the JD9. Here is the unique question:

Would this be a tube issue? I don't know how many hours are on these tubes. This is a dedicated demo unit from Needle Doctor. They are willing to sell it for the price of the non-upgraded Jolida, so that in itself a fairly decent deal. I had already planned on doing tube rolling and an OPAMP upgrade if I buy it, but given what I am experiencing, I do have some doubts about spending nearly 700 on this unit.

I must also note that I removed the tube shields as an experiment as well, with no change in the outcome, as the sound still becomes veiled after listening for more than 15 minutes after initial power up. Also, the change must be gradual, as I don't notice an imminent change, it just slowly becomes apparent to me after listening for awhile.

Has anyone else experienced this issue?



-Jason

 

[bobins08]

There is a huge thread on the JD9 that gets into all the mods and all the settings ... its the good, the bad, and the ugly of the JD9.

I picked a used JD9 about 6 years ago for $150, so I have an early version. I have done a lot of mods to it and learned a lot along the way. My technical opinions are all over the thread so I wont rehash them but here is a summary.

I think the JD9 is a poor design that can be transformed into a unit that produces sound very good. I think it is way too expensive for what you get and you can spend less and do better on other phono amps without all the mods. I think the JD9 has way too much gain and some of the specs that Jolida puts out relative to gain and switch settings are just plain wrong. At least for the early version that I played with.

I think the problem you are hearing is likely to be tube related. Could be the power supply caps too. It needs a good power cord and it needs to be far away from other electronics that could cause RF interference.

Yes, it can produce sweet sound but it is very hard to get a black quiet background without some major component upgrades. I found basic electrical design no-no's with my early version unit such as Jolida bundling power supply wires with the phono signal wires. Simple fix but poor attention to detail.

The OP AMP upgrade really improved the sound (not cheap either ) but it will not help this problem. You have a defect somewhere, this is not normal,

I refer you to the Jolida thread for more.

 

[sqlsavior]

I had already planned on doing tube rolling and an OPAMP upgrade if I buy it, but given what I am experiencing, I do have some doubts about spending nearly 700 on this unit.

I had a JD9 that would make intermittent pops and buzzes after warming up. Then when I took it to a friend's house, while we were all listening, and liking what we heard, it started sounding like the garbage disposal was running. When you could get one for $300, it may have been a nice experimental unit. But they are pretty colored out of the box, and failure-prone in my one-sample experience. There are better sounding options out there, for less money, so I'd have doubts, too. Get something else.