Review: Jolida JD-302b Tube amp

This system has probably evolved since the review was posted HOWEVER . . .

I am a new owner of a 302B and thought I'd put in my 2c on the subject.

The unit I purchased was a "modded" one through Underwood HiFi. I can tell you that the service from them is unbelievably great. Without having a comparison to the non-modded version, I cannot speak to that. However, I can say that the insertion of the 302B in my humble system was like night and day.

It replaced an Electrocompaniet ECI-4 (ss integrated 120WPC). Anyway I just wanted to get back to tubes and the 203B seemed like a solid option. It was. The increase in detail was astonishing right from the start. And this was before the tube rolling (now a BRAND NEW HOBBY for me).

The soundstage opened up compared to the ECI-4 and the power differential between the two amps was immaterial (it's a pretty small room anyway).

On to the rolling -- First in went a pair of Mullard CV4024s in place of the 12AT7s. Oh my. The soundstage widened. The imaging became dramatically more precise and the little harshness in vocal frequencies (likely just at the cross-over frequency of my B&W 805's) went away. What a difference. If I made not other changes to the tubes this improvement was all I could ask for. HOWEVER. . . next came a pair of 1961 vintage Sylvania 12AX7s. Well, no more brightness at all at the highs (something possibly in the Mullards makes them just a touch on the zippy side. The imaging remained but the soundstage stepped back a bit.

Last but not least was the insertion of a matched quad of Svetlana EL34s. Back came the soundstage into the room once more and the silky tones of the mostly female vocals I listen too emerged in full throat. The spookiest listen to date is Jane Monheit doing "Over the Rainbow" in which she opens from dead silence into a capella -- really hair raising.

Anyway, now that the intial round of rolling is over (like I said it's now a hobby) I am changing out ICs to see if I can get even more out of this wonderful little amp. My hat's off to Walter at Underwood Hifi for coming up with the mods and for the incredible service. Even though they are across the country from me, I will use them again and listen to the recommendations from there as well. As for the 302B -- I couldn't be happier. Actually I suppose I will be when the new ICs and DAC go into the system.

System Used (before all the cable changes with upcoming mods ID'd:

Parasound CDC1500 (just as a transport (Nakamichi coming in)
Audio Alchemy DTI 2.0 (AA DTI Pro 32 coming in)
Audio Alchemy DDE 3.0 (Channel Islands VDA-1 coming in)
The Jolida
Cardas IC's (Bolder Cable and RS Audio coming in)

Enjoy.

F7

My experience with JD-302B is that stock it sounds good and is a great value when the price is factored in.However, It can be improved by various upgrades and mods.Two easy upgrades are to replace the EL-34 outputs with premium types - I like the Groove tubes- and use a premium power cord like the Audience Power Chord. A more ambitious mod is to replace the four coupling caps with Aurio caps. With these mods and upgrades in place the sound is elevated to another level equalling amps costing 2 or 3 as much.

Just another update on the little tube amp that could.

I've got the CI modified DAC in line with the DTI Pro 32 and am now experiencing cable blues. Not real blues mind you but the insertion of an as-yet unbroken-in Illuminati D-60 has moved the soundstage back together. (Clearly this is not the Amp's doing. Substituting an Onix 0.5 m line between the DTI and the DAC brings it forward (even though there is some discussion that digital cabling should be AT LEAST 1.0 m in length). It's an interesting A/B comparison to have the soundstage compress and expand with the substitution of a cable. Anyway, the D60 will stay in til I get about 100 hours on it and then make a final determination as to its status. I have scheduled to move in an Acoustic Zen MC2 in place of either the Onix or the D60 and this one is already broken in (Thanks Disco) and that should really open things up.

Anyway, the process is now at the cable stage (new PC from Zu Cable coming for the Jolida -- New ICs from the DAC to the amp and Bybee filters to go in-line as well). All of this to see where I can get the amp to become the limiting factor (if I can with the current set-up). Thus far, particularly after rolling in the Mullards for the 12AT7 tubes -- this little jewel of an amp has made wonderful sounds out of a limited system. I am planning on maximizing the situation by getting the cables "out of the way" and seeing if there are limits to the musicality of the amp. That's the most surprising thing is the complete enjoyment obtained in listening to it. No fatigue, just great vocals floating in space on an invisible stage in front of my near-field listening post. At the best arrangement thus far, the imaging of the system was near pinpoint and plenty of air around each vocal and instrument. The cables coming in will make a tremendous difference but I'm letting my patience ride herd in order to incorporate as few changes at one time as possible. Will I find a ceiling on the amp's capabilities? Probably. But by then I should be at the max in my other componentry. I'll continue to post on this thread since those folks who get the Jolida, especially the modded one out of Walter at Underwood HiFi, should know what other components (within budgetary concerns) optimize the presentation. I'm going to look at some different 12AX7 tubes as well. The Sylvanias I have did compress things a bit over the EH's provided by Underwood in the original mod. There are some out there that could really wow the audience -- especially if you are the audience in front of the music generated by this unit.

F7

OK, so no one's reading this stuff except perhaps those of us who own the little amp that could. Well, for those few of us here's the latest:

Rolled out the Sylvanias (I had made some other changes in the system and lost some of what I had come to tap my toes to). Rolled in a set of Mullard ECC83s. Oh my. The soundstange came back, the imaging improved mightily and the layering of the musicians/voclaists became instantly (and I mean within five minutes of powering up) was really improved. It likely helps that I took an extra fifteen minutes to set the bias on the EL34s in the unit too but that probably accounted for the complete removal of sibilance more than anything. I'm looking now for a set of JJ Tesla E34L blue glass just to compare to the Svets which are already really nice. I'd get more Mullards for these but the price on the truly good ones is way up there.

IMHO for the 12AX7s that I have: Mullards are No 1 by a longshot with the OE ElectroHarmonix in second and the Sylvanias trailing by a lot. The recommendation I got that caused me to jump on the ECC83s was that the Jolida really likes Euro tubes (something to keep in mind).

I'm putting in a new PC tonight for the unit and in a couple of hundred hours I should have a read on what this does.

F7

The 302 is a sweet, clean sounding amp. the gear has undergone many improvements since original models. And there are upgrades. One can upgrade caps and resistors and diodes and even wiring. Jolida can do it. Many people do this stuff themselves. I have been selling Jolida gear for several years. We have had very few problems, many happy customers, and Jolida provides great support. The 1501 hybrid is overlooked, but has a real nice sound with upgrade package 1. At the prices paid you cannot expect to have the very best tubes and capacitors, etc. Those items get costly. You want the very best get out 3k to 5k at least. if you want a great value Jolida provides that. hope this helps someone to make a decision. I have a 502 hooked up to some Advent 6003s now using the DACIII upgraded. It sounds super to me. Those Advents go great with a tube amp.