2. tech-talk
  3. 149971-132266

Mitsubishi DA-A10

I am considering changing the capacitors in this amp I picked up. I am not electronically trained, but I am relatively handy having built my own house when i had more time many years ago, and graced with lots of curiosity. I realize professionals exist for this purpose, but the cost/benefit ($250-300 for the recap) for the application of this amp isn't that attractive. Looks like about 14 capacitors- about half Elna and the others Rubycon. I did some research and lots of love for Elna Silmic capacitors but cannot find all of the voltage/uf ranges that are in the existing amp. Between Nichicon and Elna I think I can get it covered- but if Elna has the best sound preference would be to do it right. Plan to replace them all regardless of good or bad since I don't know how to test. I do have a multimeter. I suppose if I get a bad new one I will need to do some testing and may cross that bridge then.

So now to my here is my question- two of the capacitors 80V 470 UF have three leads- +, -, and NC. I have researched what the NC means, but haven't found suitable 3 leads on line. Any help appreciated.

Please, if the response is "stop being an idiot and take it to a qualified technician", that isn't going to happen as I am curious about how this stuff works. I understand as professionals if you prefer not to contribute. Thanks in advance.
ovinewar

Showing 6 responses by ovinewar

ovinewar's avatar
ovinewar OP
172 posts
 
Thank you for your response. It doesn't look that daunting- now that I have it opened up. I am excited about tackling it. I will post pics here of the insides if people are interesred. I think I will also change out the horrible speaker posts. Again, thank you Viridian. 
ovinewar's avatar
ovinewar OP
172 posts
 
So I knocked most of these out in a flash. Good quality solder and a sucker tool was my best friend. Two of the caps were difficult to see when on the board but now realize they are non polarized. I didnt take them out as I have no replacements. 

I didn't see Nichcon FG, which I used everywhere else,  having non polar caps. I need a 33uf 25v and a 22uf 25v. Any suggestion? 

Also, some additional insight into this statement would help.

" Should any of those caps be used in the signal path for coupling then they will make a larger difference and they should be replaced with a film cap, or if the film cap in the original value, is too large, use a film cap as a bypass on the electrolytic."

Thank you in advance. 
ovinewar's avatar
ovinewar OP
172 posts
 
Thanks of all the advice. I ordered an inexpensive variac as I am going to tackle few more pieces of vintage gear. Too late on the methodical approach. I have already replaced the caps on both sides. Appreciate the manual. I had tracked one of those down before I started. I wont fire the amp up until I get the variac. Thanks again
ovinewar's avatar
ovinewar OP
172 posts
 
So finished everthing today and fired it up using the variac. The sound was unbelievable. Even my wife- who isnt that interested, said it sounded great. Could be she was reacting to my ear to ear grin, but it really sounded good. I assume when caps burn in it will improve. Thanks to all. 

Now takling an old Nikko tuner!
ovinewar's avatar
ovinewar OP
172 posts
 
No progress thus far. It has a bajillion capacitors! They all looked pretty good. Issue is it will not tune on a station. I have been googling but havent found a good solution as of yet.
ovinewar's avatar
ovinewar OP
172 posts
 
Thank you viridian. I have both the f-20 and the f-10, as well as a c20 and agree the tuners are great. The Nikko isn't a cap issue- most likely something simple in an open circuit that will not allow it to lock on a station.  I am not going to put too much effort into it- I just dont like to trash things that are vintage and well made. 

 I have several vintage Mitsubishi pieces- 4 amps and accompanying pre's and tuners. In my uneducated opinion, they are really well made and sound fantastic. The amps had funky speaker connectors but I discovered an easy upgrade to banana posts that looks factory. I drive Vandersteen's vertically biamped with 2 da-15's and they sound incredible to me. I am weak on sources. I have older CD players but need to upgrade or consider a streaming device. Any suggestions sub $500-700 used is welcome. 
More to discover