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Mitsubishi DA-U310 Restoration

Number one rule in replacing caps is to replace electrolytic caps with electrolytic caps except where it is possible to replace them with film caps due to the low values (<10mfd).
 
Ceramics are higher in distortion and are only low values pf, < 1mfd. Film caps are better where space is useable up to 4.7mfd.
 
Oh, I decided to go with all electrolytics anyway, all panny FC's. I guess the idea of using ceramics was pretty stupid, thanks for the FYI so I don't make that mistake in the future.
 
Got the Tone control and mic board re-capped.next up will be the preamp/ psu and finnally the two caps on the power amp board.

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All done and back together. Tested it's output 57 watts into my 8ohm load at 1khz. Might get a tiny bit more umph out of it if i up the filter caps.

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Pretty nice, I've been listening to it for the last few hours. The highs definitely have a lot more presence, cymbals are a lot more sibilant but in a good way. Lyrics are a lot more defined and the bass sounds a bit harder, not as slack. I definitely know some transistors have to be changed. Still got a bit of background hiss, I'm thinking it's the 2SA798's in the pre amp. If not my next guess would be on the IC chips in the tone circuit.
 
Another little update, I replaced the Mic input level pot with a new 20k pot. The old one had a rough spot I couldn't clean out. I also ordered a replacement Bias adjustment pot. Yes, one... Apparently in my sleeping drug induced stooper I ordered one instead of two... it's other half will be here tomorrow. I also decided to change the title of this thread a little, since this has pretty much turned into a "sorta" restoration.

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This is fantastic work!

I've got the exact same amplifier. I have never done an amplifier restauration, my electronic knowledge is not that great. However i can solder pretty well. So i guess i will take it step by step. I got the service manual with it, and i think i should first recap it. And i want to mod the lighting to LED. What LED's are you using?
 
Terracide said:
This is fantastic work!

I've got the exact same amplifier. I have never done an amplifier restauration, my electronic knowledge is not that great. However i can solder pretty well. So i guess i will take it step by step. I got the service manual with it, and i think i should first recap it. And i want to mod the lighting to LED. What LED's are you using?
Click to expand...

Thanks, Re-capping one of these is definitely worth it they have a very nice detailed, powerful and clear sound. Not quite sure what LED's they where, they where in the unit when I got them, I've since converted it back to incandescents the LED's had an Issue with being slightly different colours. They where an SMD round type LED with leads soldered to the legs. I wish you the best of luck with your restoration, reading this made me want to put my DA-U310 back in my main system for a little while.
 
I like to replace the bulbs in the VU-meter. They are not there anymore. Can anybody tell me what I can ask for when I'm in the shop? Maybe someone knows what bulbs belong in the DA-F210?
 
Bert S. said:
I like to replace the bulbs in the VU-meter. They are not there anymore. Can anybody tell me what I can ask for when I'm in the shop? Maybe someone knows what bulbs belong in the DA-F210?
Click to expand...

I used, 10v-15v 55mA lamps when I replaced mine. I got them from RS components.
 
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