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    Nichicon cap placement on M-125 driver board

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    buchela

    Posts : 30
    Join date : 2011-03-09

    Nichicon cap placement on M-125 driver board

    Post by buchela on Fri Apr 01, 2011 12:19 pm

    Hi everybody I'm new here.I just finished the driver board for my first monoblock M-125. I have a doubt on the orientation of the two NICHICON capacitors, when I cut the leads I forgot about the longer positive lead of each, and now I'm not sure whether or not they are installed correctly. As they are, the grey band on one side of both caps are facing out (towards the edge of the board).
    Also, I'm using rosing core 60/40 for soldering and a 25 watts pencil type iron, am I braking any rules with this?
    Help will be greatly appreciated.

    Luddite

    Posts : 235
    Join date : 2009-02-04
    Age : 66
    Location : Texas

    Re: Nichicon cap placement on M-125 driver board

    Post by Luddite on Fri Apr 01, 2011 1:44 pm

    buchela wrote: Hi everybody I'm new here.I just finished the driver board for my first monoblock M-125. I have a doubt on the orientation of the two NICHICON capacitors, when I cut the leads I forgot about the longer positive lead of each, and now I'm not sure whether or not they are installed correctly. As they are, the grey band on one side of both caps are facing out (towards the edge of the board).
    Also, I'm using rosing core 60/40 for soldering and a 25 watts pencil type iron, am I braking any rules with this?
    Help will be greatly appreciated.

    Buchela,

    The grey band normally indicates the negative (minus) lead, which most likely connects to ground (earth). I don't have a schematic for the M-125, but I'm sure you do have one and you should be able to confirm the capacitor orientation from that. Your 60/40 solder and 25W soldering iron are just fine. Enjoy building your amplifier(s)!

    Best Regards,
    Charlie


    buchela

    Posts : 30
    Join date : 2011-03-09

    Re: Nichicon cap placement on M-125 driver board

    Post by buchela on Fri Apr 01, 2011 2:46 pm

    Thanks for your reply Charlie. I am not very good with schematics, but after looking into it yes your assessment is correct, the negative lead goes to ground.( I just found it in the "wrong place" next to the transformer symbol, I thought it was missing from the schematics, lol )
    Thanks for helping me to learn something.

    j beede

    Posts : 328
    Join date : 2011-02-07
    Location : California

    Re: Nichicon cap placement on M-125 driver board

    Post by j beede on Fri Apr 01, 2011 3:06 pm

    buchela wrote: Hi everybody I'm new here.I just finished the driver board for my first monoblock M-125. I have a doubt on the orientation of the two NICHICON capacitors, when I cut the leads I forgot about the longer positive lead of each, and now I'm not sure whether or not they are installed correctly. As they are, the grey band on one side of both caps are facing out (towards the edge of the board).
    Also, I'm using rosing core 60/40 for soldering and a 25 watts pencil type iron, am I braking any rules with this?
    Help will be greatly appreciated.

    Are your joints bright and shiny? Good. Are you melting or scorching the insulation on your wires? If so you may be applying heat too long. Keep that tip clean and wet with molten solder. Do you have a damp sponge for wiping your tip?

    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Nichicon cap placement on M-125 driver board

    Post by Bob Latino on Fri Apr 01, 2011 5:00 pm

    In the M-125 VTA board manual it states as below in step 11 ..

    "11. Install C14, the 120 Mfd 450 volt capacitor and C16, the 47 Mfd 450 volt capacitor, on the TOP of the board in their proper locations. Make sure that the POSITIVE LEADS on both capacitors are installed in the SQUARE pads on the board. On the 120 uF cap the positive lead is the one furthest away from the black stripe on the side. On the 47 uF cap the positive lead is slightly longer than the negative lead. On both caps there is a stripe on the side of the cap next to the NEGATIVE lead. Solder in on the bottom of the board."

    The Nichicon caps have a GRAY strip instead of a BLACK stripe but the striped end (negative lead) should be installed in the ROUND soldering pad and the positive lead should be installed in the SQUARE soldering pad. I have made a note in the manual now to designate that this stripe may be EITHER black OR gray. Sorry for any confusion that the actual color of the stripe (black or gray) may have caused.

    Bob

    buchela

    Posts : 30
    Join date : 2011-03-09

    Re: Nichicon cap placement on M-125 driver board

    Post by buchela on Fri Apr 01, 2011 5:24 pm

    jbeede: some joints are shiny some are not although I have tried by redoing it. I am very concern with overheating electronic parts. I am using a rosing core solder 60/40 that make it easy to solder electronic parts. I think the trick is to cut the leads of the component in such a way that barely protrudes from the board and so the solder flows nicely leaving a shiny joint.I found this out after the first few joints. I would like to hear from the experts in this regard. Thanks for sharing your expertise

    buchela

    Posts : 30
    Join date : 2011-03-09

    Re: Nichicon cap placement on M-125 driver board

    Post by buchela on Fri Apr 01, 2011 5:36 pm

    Bob: Thanks for replying. All the 4 cylindrical capacitors that are to be installed vertically ( two on top of the board and two on the bottom- the Nichicons ) are black and they all have only gray stripes.

    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Nichicon cap placement on M-125 driver board

    Post by Bob Latino on Fri Apr 01, 2011 6:00 pm

    buchela wrote:Bob: Thanks for replying. All the 4 cylindrical capacitors that are to be installed vertically ( two on top of the board and two on the bottom- the Nichicons ) are black and they all have only gray stripes.

    Yes - The 120 uF and the 47 uF Nichicon's are installed on the TOP of the board and the two 100 uF 100 volt Nichicon caps are installed on the BOTTOM of the board.

    Bob

    buchela

    Posts : 30
    Join date : 2011-03-09

    Re: Nichicon cap placement on M-125 driver board

    Post by buchela on Fri Apr 01, 2011 11:36 pm

    Bob: what I tried to convey was that the caps in question can not have a black stripe because their body is black. A black stripe on a black body ? I only know that I don't know, but there is always common sense, if there no black stripe there is a gray stripe, no biggie. The instructions manual for the M-125 by the way is a master piece. one of the most detailed complete accurate and carefully worded I've ever seen. This is how an instruction manual should be made. I asked for help regarding the Nichicon caps not because the manual is confusing, but because I've got distracted when I installed them. Now if you want to make it foolproof...you are very close.
    Whoever created the steps and put together the M-125 instructions manual,congratulations. Great job.

    Luddite

    Posts : 235
    Join date : 2009-02-04
    Age : 66
    Location : Texas

    Re: Nichicon cap placement on M-125 driver board

    Post by Luddite on Sat Apr 02, 2011 2:32 am

    buchela wrote:jbeede: some joints are shiny some are not although I have tried by redoing it. I am very concern with overheating electronic parts. I am using a rosing core solder 60/40 that make it easy to solder electronic parts. I think the trick is to cut the leads of the component in such a way that barely protrudes from the board and so the solder flows nicely leaving a shiny joint.I found this out after the first few joints. I would like to hear from the experts in this regard. Thanks for sharing your expertise

    Buchela,

    Actually it is preferable to leave the leads uncut until after they are soldered in place. This allows for easier insertion and positioning of the components. You should also bend the component leads about 45 degrees (opposite to each other) which will hold the component in place while soldering. After the solder hardens and after you have inspected the connection, then and only then should you cut the leads. There is truly no advantage to cutting the leads before soldering. In fact, that would make it more difficult to keep the soldering iron tip in contact with both the pad and lead, which is vital to getting the solder to flow properly. BTW, you should only use rosin core solder (nothing else) for all electronic soldering.

    Best Regards,
    Charlie

    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Nichicon cap placement on M-125 driver board

    Post by Bob Latino on Sat Apr 02, 2011 3:33 am

    Buchela,

    Glad that you like the M-125 manual. It took a long time to write and check over for errors, unclear statements etc. The issue with the stripes on the caps came up as a result of switching from Xicon and Cornell Dubilier power supply caps to all Nichicon caps. Xicon and Cornell Dubilier caps are BLUE in color with a BLACK stripe. Nichicon caps are BLACK in color with a GRAY strip. I made the cap switch but did not update the manual. I updated the M-125 manual yesterday to reflect the change in power supply caps.

    Bob

    j beede

    Posts : 328
    Join date : 2011-02-07
    Location : California

    Re: Nichicon cap placement on M-125 driver board

    Post by j beede on Sat Apr 02, 2011 1:48 pm

    buchela wrote:jbeede: some joints are shiny some are not although I have tried by redoing it. I am very concern with overheating electronic parts. I am using a rosing core solder 60/40 that make it easy to solder electronic parts. I think the trick is to cut the leads of the component in such a way that barely protrudes from the board and so the solder flows nicely leaving a shiny joint.I found this out after the first few joints. I would like to hear from the experts in this regard. Thanks for sharing your expertise

    Soldering is a bit of an art and it usually takes a little practice to get it just right. 25W sounds a little lightweight to me... The fact that you are getting better results with short leads seems to support my concern. I agree completely with Luddite that you should be leaving the leads long--clipping them short after soldering. The longer leads act a little like a heat sink, giving the heat a place to go other than into your component. Be sure to let the joint cool slowly and with ~zero vibration. I don't recommend multiple reheating cycles, but if you have a small "tin" of rosin or a rosin "pen" you might try adding a bit of rosin and re-flowing the dull or cold looking joints. I know some people think a lower power soldering iron is somehow safer for the components than a higher powered one. I use a 50W pencil so I can flow the solder quickly before the entire node or component gets too hot. Are you melting or scorching the insulation on your hook up wire? That can be a sign of too slow heating. I bet Bob's manual includes a good soldering advice page.
    ...j

    buchela

    Posts : 30
    Join date : 2011-03-09

    Re: Nichicon cap placement on M-125 driver board

    Post by buchela on Wed Apr 06, 2011 12:05 pm

    Thanks guys, I put into practice Charlie's recommendation and VOILA !!!!! IT WORKS.
    I have not soldered in quite a while, since back in the seventies when I used to be involved in the manufacture of transformers. The only refresher I had was when I got the Haffler DH200 kit, but that was waaaaay back. Upon recommendation, I chose the solder that I am using Kester 60/40 for its excellent wettability, that threw me off, because I have never used before, back in the days we used a harder to melt solder. This sucker melts instantly and hardens the same way. Cheers

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