Jolida Jd9 Mod Project

[midfi]

are my eyes playing tricks on me or are they tied in with the Obligattos?

[Wire Nut]

No tricks- I bypassed the Obbligato's with the Auricap- that is why I was happy with the dynamics of the sound.
If you look closely at all of the cap photos you will see bypass- first it was the Vishay that Tony G raves about, next it was the Russian Teflon's and finally the Auricaps.

There will be more tomorrow as the Mundorf's arrived, but they were out of stock on the Silver/Gold that I was going to use as a bypsss... so I am installing V-Cap copper/Teflon. They are supposed to be the best caps in the world!
(I was saving the V-Caps for another project- but what the heck, I am loving vinyl again)

[Wire Nut]

The Mundorf Supreme's and V-Cap CUTF's are installed. They look great! The sound verdict is still out as they say the V-Caps require 200 hours to brake in. My initial observations are that this set up is more delicate at hour one. I will let you know how they sound in a week or so.
Here is what they look like:

[Wire Nut]

Terrific! The new caps have three days on them and I can report that they sound terrific. They are almost holographic in soundstage. I would recommend this cap combo to anyone that can afford the extra ging for the V-Caps.



That leads me to post to someone that is interested in doing this upgrade- I have put together a "starter kit" for the JD9 upgrades from my "pulls" and extra wires, etc at a really good price. PM me if interested.

[Wire Nut]

I can now tell you that after over 200 hours of playing time, the V-Caps with the Mundorf are just wonderful. Fast, ballanced, wide sound stage, and just about everything else you could wish for!

[Bob in STL]

Bravo. Fantastic work.

I just learned a lot reading your thread.

You said you "settled on regular vintage Mullards".

I am not looking to do anything as ambitious as your mod yet but if I were to try a simple tube roll to replace the stock tubes would some new Mullards (gold or platinum) be a good choice and improve the performance significantly? I think they are available in the $25 per tube range.

thanks, Bob

[Wire Nut]

Bob, the stock tubes are pretty harsh. Most of the posts about this preamp start with tube rolling. Some have used the very tubes you mentioned with good results. Don't forget to take off the stock coolers and put on some tube dampers.
Also the large cap replacement is easy and gives good results.

[Rothwellaudio]

I've never seen the point of tube dampers - they only damp the glass envelope and have no effect on the stuff inside which actually needs damping. After considerable experimenting I concluded that soft-mounting the valve bases (or the circuit board that the valve bases are on) has a much greater effect.

[Ldg]

Some valves have internal vibration damping material, such as EF86's, which are specifically designed to avoid microphonics, especially for use as small signal audio pentodes. The effectiveness is said to vary between manufacturers. But not many valve types have any such arrangement, nor need it really, especially triodes, as RA says. And one can tell by tapping the envelope gently if there's any problem to solve, but even so it's not the glass that is strictly the microphonic bit, it's the internals as RA posts, so seems not much mileage in the rings per se IMO, but they're harmless enough.

[Wire Nut]

I am guessing from both of your posts about tube dampers that you have never actually tried them.
That would be like me saying England is ugly and why spend the money to go there... even though I have never been there myself?
I heard a difference when I used dampers & liked the results, the bass - mids tightened up. But that is my experience, your mileage may vary.

[Ldg]

I've tried similar dampers with microphonic pentodes without notable effect. Reading RA's post, it seems he has actually experimented too, hence his comment.

[Wire Nut]

ld, I have only had one microphonic tube. It was a vintage Mullard EL84 since it was microphonic, I threw it into the trash. I have no experience trying to fix that issue.
I do not use the dampers for microphonics, but for vibration. They seem to help in that arena.
Best, Nut

[Ldg]

Yes, for an EL84 to be microphonic, something structural must have come loose internally, methinks. Most of my work on reducing microphonics/vibration has been with small signal pentodes, EF86s and EF37s, which are notoriously prone. Its possible EL84s have internal damping components, they were targeted for audio, but AFAIK only a very few small signal pentodes have it. As RA says, it's the internals that vibrate and are at issue.

[Bob in STL]

Bob, the stock tubes are pretty harsh. Most of the posts about this preamp start with tube rolling. Some have used the very tubes you mentioned with good results. Don't forget to take off the stock coolers and put on some tube dampers.
Also the large cap replacement is easy and gives good results.

Wire Nut,

I just rolled the stock tubes for a matched set of Sovtek LPS. I took off the coolers, added the dampers (two per tube) and I am very pleased with result. The improvment was drastic. Just as noticable set up as the day I added the Jolida with stock tubes. The Sovtek's are giving me better and deeper bass. Sound more open, natural and better space. Listening to Steely Dan and Victor Feldman's percussion parts sound much clearer and more noticable than before. The noise level is reduced, especially noticable inbetween songs in the quiet parts.

My B&W speakers sound like they did in the stereo store ... This is what I thought I was buying!! There they are!!!

This tweak, along with adding a Jico SAS stylus to my V15-III have taken my stereo to new levels.

The other mods will come later. Too many projects.

thanks, Bob