Amplifier "Mashuni"

Discussion in 'The Projects Forum' started by R!f@@, Apr 13, 2011.

  1. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    I've had a hard time figuring out a title for this project. ....& I thought what the heck, I would give it a little of you and a little of me.

    Anyways, this may not be a project for me but rather a paying job but I thought if I documented the works it would inspire others to do the same, or even better with a little help. :D

    My dad's brother wanted to have his old Panasonic Hifi made smaller. Since that stereo is truly a work of art from Panasonic. It was like decades old, but it still produces powerful bass and clear sound and buying any other that would even come close to this one is out of the question here.

    This place is small so we need little things, but it should be chest thumping. Other thing is the era of cassette tape is gone. Now we use a PC to play music, well most of them.

    What this project is all about is to put this

    [​IMG]

    in to this

    [​IMG].

    Well not all of them. Just the useful parts for this era. :D
     
    Last edited: Apr 13, 2011
  2. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    The amplifier is, I think made by those cheap Chinese products. These things are sold here in millions. :mad:

    I first wondered how I am supposed to do that. The Hifi is Big and the amp is tiny. :eek:. Even the Heat sink won't fit in it.

    But I always have a way of doing things, I dunno how or why these ideas comes to my head.
    I have to do what I always do.
    First part is scrape of the unwanted parts.

    But before that I like to tell u that my uncle wants the amp, the equalizer, and the bass control too. Meaning these functions should end up in the final product.

    I have no idea what so ever yet in how to do that. So first things first.

    Take out the junk.

    [​IMG]


    [​IMG]

    [​IMG]

    [​IMG]

    I am so merciless....
     
  3. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    As u can see from the picture the HIFI has a large heat sink. A big transformer and a fan too.

    Without even thinking, I dismantled the whole thing and threw away the CD part, tape decks and all of the metal parts. All I need is the amp and the controls, nothing more.
    From the pics you can see the Panasonic hifi came to be. :D.

    [​IMG]

    Some people just shed tears when they see me do things like this...

    All I can say is "why did you come to me in the first place?"

    Now it's time to go thru the circuit....

    After a detailed study, I know I can use the amp but the bass boost circuitry is within the tuner and tape amp and input selector PCB. Since what uncle want is just one input he would be using it with the PC, we don't need no input selector or tape or CD or tuner or things we hardly use.
    which means I only need the amp PCB and the TX. Simple. No?

    I am sure I can bypass the control signals and all that thingies that are connected from the amp PCB to the controller PCB, which by the way is just too big to put any where, which means, it has to go...

    I still dunno how the preamp and tone control of the karaoke mixer sounds like, and what to strip from that too.

    Next is to look in to the karaoke. All it has is just one PCB and a TX and plenty of space for me to do what I want. But one problem. It is just too thin.....what to do .....what to do...........!! :confused:

    From the looks of it, I can put the amp PCB but not the heat sink. Heat sink has to go. Now if I take out the sink I can put the amp neatly in to the chassis provided that I take away the current amp areas of the Karaoke.

    All I need is a heat sink, with forced cooling, the amp won't over heat if the heat sink is thick enuf.
    Next I went thru my heatsink junk and found just what the doctor ordered.

    [​IMG]

    It's size is perfect. I can use the same technique the Panasonic has used. I can put the sink in the back of the chassis, which means I have to cut off some area.

    Time to go to a machine shop.

    You wouldn't believe how much these Neanderthals charged me just to do this

    [​IMG]

    The back side of the chassis is done, now to mount the Amp PCB on to the heat sink. But before that I got to do some dry joints and remove unwanted connectors,


    [​IMG]
     
    Last edited: Apr 13, 2011
  4. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    After a bit of drilling and some filing, the Amp is mounted on the new Heatsink.

    [​IMG]

    The Power Module and the regulators are mounted the same way as it was done on the original sink with a little bit of modification.

    Now to see how fits.

    [​IMG]

    Not bad HUH !!

    Now for some PCB Support...hmmm..stand offs.

    The amp PCB has holes in it. Again a little bit of drilling .......

    [​IMG]

    and viola

    [​IMG]

    Perfect...:D

    [​IMG]
     
    Last edited: Apr 13, 2011
  5. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    [​IMG]

    It is just too perfect...I sometimes amaze myself u know....:D
    Now to scrape away the karaoke PCB's amplifier.

    [​IMG]

    Now I need to do away with the sink, and I won't be needing them transistors too.. .......after a few minutes of brain storming I came up with this idea

    [​IMG]

    See the line. It is a ground line separating the low signal side from the amps. I do not not need no cheap amps, so it has to go, together with the PCB.

    After a few minutes of dremel sawing the board is halved

    [​IMG]

    and it fits too perfect....................

    [​IMG]
     
  6. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    In order to route the wires I need to see how I can route 'em and how long it should be, so next is the transformer.

    [​IMG]

    :confused: The bloody thing is just too big. There is no way I can put it into this chassis. I have plenty of space but not the thickness..:eek:

    Then it hit me.....to scrape off the unwanted.
    you wouldn't believe this but I got some unwanted metal from the former too. See below...

    [​IMG]

    Now the thickness is perfect. I don't I have to use screws to mount the Tx as the cover will give a tight fit and will hold the tx is place. But I guess that is not an option. Still I got it in.

    [​IMG]


    Now comes the connection and all the works. Let's see what Happens...

    Thread is open for comments now.........since I am working on the wiring. The rest is coming soon with in a day or two....:D

    Will it work or Do I have to throw the whole thing into the junk....

    *Need to get some shut eye....
     
    Last edited: Apr 13, 2011
  7. debe

    Well-Known Member

    Sep 21, 2010
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    I like this project R!f@@. Its brilliant & im confidant it will work. Cant wait for the finished project.
     
  8. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    OK..Manage to find a way to fix the tx. and tap off preamp power to the preamp board from the amp PCB.

    Fixed a bug in the karaoke pcb, now I can get an Audio Output from it :D.

    Got 'em pics, but wify took cam to hospital, her aunt had a baby.

    So now I am mounting everything and will attend the power stage.
     
  9. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    I wonder why u need so many primary tapping....

    [​IMG]

    Tested the Tx and I knew I have to mount the TX pcb, so part of it has to go.........

    [​IMG]

    Some more drilling and some more standoffs and finally it came to be..

    [​IMG]

    The Zeners and regulators from the karaoke has to go.......

    The Power amp PCB has the necessary ±15VDC. Tapping in to it is no biggie.

    [​IMG]
     
  10. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    [​IMG]

    Speakers jumpers and all are pretty much the same.

    A sound test surprised me for the fact that it gave an out put to the speaker. cause I have yet to bypass the muting and the protection and all those stuff that are usually there.

    I thought this was way too easy..but I was wrong...
    It plays nicely at lower volumes but when u crank it, the bloody thing Mutes. :eek:...

    I knew it...something is always there to make things worse...
    Started to poke around and found no varying or switching voltages. :mad:

    Which means I need to go for a Schema Hunt to FSM.
     
  11. CDRIVE

    Senior Member

    Jul 1, 2008
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    Quite an undertaking and from what I can see it's very well done. I thought I was unique in always wanting to stuff 10 pounds of electronics into a one pound bag. ;)
     
  12. R!f@@

    Thread Starter AAC Fanatic!

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    Well....after all the cracking it turn out to be a simple thing.
    The Fan circuit is muting the amp when amp is maxed. Why ?
    cause I haven't connected the freakin Fan.

    It seems I don't need to do anything. All it need is audio input and power.
    it works as stand alone amp.....wouldn't u believe it.

    [​IMG]

    Sound isn't bad for such a little thing :cool:
     
    Last edited: Apr 17, 2011
  13. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    Nice work :)
    Kind of reminds me of me putting a 500W transformer and amp inside the chassis of a 2x60W home stereo :)
     
  14. CDRIVE

    Senior Member

    Jul 1, 2008
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    To say impressive still seems understated!
     
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