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Modded my Jolida 302a tonight, WOW

I purchased a used Jolida 302a from a friend, as I wanted to discover tubes and figured an entry-level integrated would be a safe, fun place to start.

When I got it from him, it was pretty much stock / factory except for Svetlana EL34 tubes and he had had the balance control eliminated.

Well, this evening I decided to get gutsy and got out the screwdriver and put her on the operating table. My goal (and end result): elimination of the source selector and rewiring the inputs directly to the volume pot. A little soldering and such later, I took one of the pair of 4-conductor shielded wires and removed it, using the remaining one for separate runs for signal and ground on the left/right CD RCA jacks, tying the shield in with the ground only at the volume pot. I then buttoned it back up for a listen.

OH GOOD LORD!!!

What a stunning difference. That little source selector had TONS of crosstalk before (you could be on AUX and still hear CD pretty darned clearly for example), I figured it was a train-wreck in the signal path, and this confirmed my suspicions -- the difference was absolutely night and day!! I was blown away by how much better the stereo separation was as well as the width of the sound-stage (the track "The Trees" off the Spirit of Radio (greatest hits) by Rush was incredible, it opens with birds and such, and they seemed quite enveloping).

So this has me thinking, well, how badly is the quality of the (chintzy looking) volume pot affecting things? And if I can replace it, I wonder if I could put in a remote controlled one such as the ALPS I've read a bit about recently? Has anyone had experience with this or other fun DIY mods for the 302a/b? If so, please do share ;) Now all I need is some good pre/driver 12AX7/AT7 tubes... I'm leaning toward the Mullards for the AT7s but I haven't yet decided on the AX7 tubes, probably start with some Electron-Harmonix and work my way up / over from there...
128x128dmoffitt
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dmoffitt OP
66 posts
 
I'm trying some JAN Philips 12AT7 driver tubes, and will probably be ordering some Ei 12AX7s shortly and perhaps some EHs as well.

RE: the remote volume, I think she's about to go 'under the knife' again but a bit more drastic, perhaps to the extent of modifying the front of the chassis (either lengthening it or fastening a new faceplate similar to the one on the 302b) to allow room for the ALPS and remote unit etc... I'm lazy and want a juice-up-juice-down button ;) I'll probably perform a few other mods while I'm in there and post what I've done and the results.
jswallac
4 posts
 
Dmoffitt, any success with the volume remote mod? I love my Jolida integrated, but am a real couch potato when doing serious listening. I am considering getting a Creek volume control or replacing the Jolida with something that has a remote, but your mod sounds like the best ticket.
dmoffitt's avatar
dmoffitt OP
66 posts
 
I am still waiting to hear from Jolida re: the parts for the volume control, but I'm actively persuing it. FWIW, I hear they are coming out w/ a remote volume control themselves, probably be in-line like the Creek (basically a passive pre-amp) but I am not fond of the idea of introducting another set of interconnects and an entire other device inline with the signal path.

I re-re-wired the inputs a couple of days ago replacing the factory 4-pair shielded line from the RCA terminals with 2 pairs of audioquest coral (triple-balanced perfect-surface copper) with some impressive results, which makes me want to consider rewiring much more of the inner workings with yet better wire (probably 2 runs of shielded 2-pair silver for the inputs and unshielded silver-in-teflon for the rest of the point-to-point wiring. I'm considering the cost of all of the above plus the ALPS project and am almost leaning toward something like a Rogue integrated or moving to monoblocks with a separate pre-amp.
loutheluthier
1 posts
 
I've got a 302 I'm trying to convert to a 502. I cant get any clear info. Any ideas? I know the basics, but actual resistor chages and bias adjustments have me concerned. By the by bypassing the ballence controll and the little board on the volume pot makes a big difference. This amp loves to be moded, the transformers are powerful and can take anything I can throw at them. Feel free to email me with any info, I can use the help.
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