Palladium LA-1000 pre-amp and Revox Evolution stereo system (#P2)
Well, this weekend I’ve been busy replacing dead and leaked caps from something not too Wan-Hung-Lo-ish…a Palladium LA-1000 pre-amp (“Vorverstärker”) back from the 80’s. These are still sold for absurd amounts of money (just like the Revox described down below), so I decided it’s worth a shot. Details on that thing are scarce, and so I’d like to post the cap list in case someone also needs replacements for their dripping electron containers.
Type Voltage Count Reichelt ### Price Total 1µ0 50V 1 RAD FC 1,0/50 0,15 € 0,15 € 3µ3 50V 1 RAD FC 3,3/50 0,10 € 0,10 € 4µ7 35V 4 TON 4,7/63 0,39 € 1,56 € <-- bipolar type! 10µ 16V 2 RAD FC 10/50 0,08 € 0,16 € 10µ 35V 1 RAD FC 10/50 0,08 € 0,08 € 22µ 25V 2 RAD FR 22/50 0,06 € 0,12 € 22µ 50V 1 RAD FR 22/50 0,06 € 0,06 € 47µ 50V 6 RAD LXZ 50/47 0,09 € 0,54 € 100µ 16V 2 RAD FR 100/16 0,06 € 0,12 € 100µ 35V 2 RAD FR 100/50 0,13 € 0,26 € 100µ 50V 3 RAD FR 100/50 0,13 € 0,39 € 220µ 10V 2 RAD FR 220/16 0,11 € 0,22 € 220µ 25V 1 RAD FR 220/35 0,12 € 0,12 € 220µ 35V 2 RAD FR 220/35 0,12 € 0,24 € 330µ 35V 1 RAD FR 330/50 0,48 € 0,48 € 1000µ 50V 5 RAD FR 1.000/50 0,99 € 4,95 €
You'll notice some caps are binned together, mostly because there are e.g. no 25V/35V types available at Reichelt...if you want the good Panasonic low-ESR, 105°C, 1-5k hours stuff. As there are few space constraints on the board and they are all dirt cheap, I don't see the point in not binning some caps together if they already match capacity. I did further binning with the Revox, so I ended up with only 17 different electrolytic caps and 14 types of film caps.
I'm not putting up more pictures of the mess (these are some crusty smartphone shots at bad lighting), as the high-capacity ones around the three piss-ant heat sinks (WHY?) have totally gone bad. I've never washed a PCB 7 times with isopropyl alcohol and got that much crap off a board. I even replaced wire bridges around a cap area because they got corroded away. The whole apartment reeked of the residue, disgusting...I spare you of further graphic documentation of that massacre.
That aside, I still not had enough of cap replacements. So I did the same on an entire Revox Evolution stereo...150 caps and some swear words later, it's now as good as new with just a few tiny botches due to the copper traces coming off the board. The PCB isn't exactly best quality and thermal stress over the years didn't burn the traces in, but made them a bit flimsy instead. And the tri-pin (main) Philips caps required botches anyway, because one cannot get drop-in replacements in this idiotic form factor - thanks again.
For that cap job, I actually bought a service manual PDF for a few dollars. Scan quality is pretty meh and there is no OCR overlay to search for part numbers or the like, but the component list really is worth the money.
So if you need such documents as well - leave me a note. I have complete lists of the needed caps just like above, and I also have some more documentation of the banana plug output board, which happened to be non-functional after some burn-in test two weeks ago. Wasn't the board itself but rather two transistor pairs for the switching relays, but that wasn't really documented in the service manual. Again, if you're repairing your own Evolution and need help, leave me a comment down below.
Tired of caps nows...
hey, i have problem with my Lenco PA-3202 which is the same with another brand like yours. the output level of the left channel is way louder than the right. i checked everything i found 2 burnt resistors at R335 2,2kohm, 1 watt. i presume there has to be another cause. could you please help me with the schematic because i didnt found it anywhere. Greetings: Ferenc from Hungary.
Hi, the Palladium unit was brought in by a work colleague and it’s been back with him after the repair. I’ll ask him if he still got documentation for it (he’s a bit of a audio geek himself).
As for the resistor, burning 2.2k resistors is serious business. Have you checked supply voltages on all of the transformer tabs?
Thanks for the good idea, but how much has to be the supply voltages? i really need a schematic.
Sorry, can’t say – no manual available unfortunately.
Hi, reading this interesting article.Just to know if anyone has an schematic of Palladium LA-1000, or Lenco PA3202 or Uher LA-1000, all are the same, I have one of this with problems… only noise coming out. Thanks
I just found this today :
feel free to use it.