modifying Unico

[Mandalabandfan]

Didn't find a thread on modifying Unico here.
Found elsewhere the famous, and rather old, commercial offerings for "level 1" and "level 2" mods, of course. I'd assume people might have done something on their own as well.
"Level 1" seems to include chassis damping, better tubes and cap & resistor changes complemented with better wiring and new rca & binding posts.
"Level 2" seems to involve rebuilding bridge rectifiers with separate diodes, BlackGates for PS and adding some special opamp board complemented with more chassis damping and new feet.

Commercial solution suggests Multicap polypropylene for inter-stage coupling cap, and Auricap polypropylene for preamp input coupling cap. Has anyone changed the caps referred - or some else? What about resistor changes and rebuilding bridge rectifiers? PS cap changes? Something else? Any experience to share about what was gained or lost by mods?

Yes, from modding point of view, Unico may well be just too fine unit as it is as standard (or with some NOS tubes), but I'm curious.

[Mandalabandfan]

I remember seeing principle level Unico schematics in net, but it seems I'm not able to find it anymore. If I remember right, it was some pdf including also bit of explanation on the design idea. Anyone else seen this, or am I remembering a dream?

Of course, if somebody knows how to get full schematics for Unico, and willing to share that info with me, that'd be just great.

[Mandalabandfan]

Ok, this seems not to be the hottest topic around. I’m not to drop the subject quite yet, though.

I'm planning to go for a mod. Some mod.
Why? I aim to make the faint speaker hiss to disappear. I’ve learned that it's normal to have a little bit of hiss, but I want to get rid of it. Another, secondary, goal is to get more tight bass. The bass of Unico is beautifully tuneful and it's got a good reach, but I think it could be a tad more tight. What else? Well, I'm pretty happy otherwise, and that's why I'm a bit worried I may lose more than I can gain. That’s the reason I started this thread in the first place: to learn if anyone has made any mods, and if they’ve gained anything by doing them.

Another thing hindering from proceeding is the nasty construction Unico has: it's not made easy to reach the bottom side of the board, but it seems you need to dismantle the whole thing. Hints and tips on that are welcome as well.

Schematics or service manual would be great, but they seem impossible to get. I'll post some photos on this thread later, in case someone with electronics knowledge would be nice enough to take time to comment with suggestions.