Adding a Quality Potentiometer to Premade Amp

Discussion in 'The Projects Forum' started by muleskinner, Sep 8, 2013.

  1. muleskinner

    Thread Starter New Member

    Sep 8, 2013
    Hello Everyone,
    I have a project I'm working on that involves repurposing an old truck radio into an amplifier/bluetooth reciever. To be clear, this isn't an automotive project, I know the rules against that. My father is a big Chevy fan, and he's finally got his own den that he can decorate as he likes, so I thought it would be really cool to take an old Chevy radio and make it into an amp/bt receiver that could be mounted into a simple stereo cabinet that he could use in that room. I sourced the radio from a junkyard, and I've already built the small oak cabinet to mount it into, but sadly I am much better at junkyard surfing and woodwork than I am at circuitry, so I am in need of a little guidance.

    To make this as simple as possible, I decided to gut a small premade amp for the internals. I went with this one as I've used them before and it works well.

    The radio face. (note, the only portion visible once installed in the cabinet is the chrome face and the knobs which aren't seen in the picture)


    Now, the amp fits nicely inside the radio housing. with room to spare as you can see. I am leaving the original parts on the left which control the frequency indicator on the radio face. (and for anyone wincing at the idea of gutting a nice 50 year old radio, this one was non-functional to start so it's getting a new life)

    The BlueTooth reciever is the next component that will need to be added, but I haven't decided on which one I want to try to add yet.

    Here are the issues I have so far:
    1. Amp volume control.
    The volume control potentiometer for the amp is cheap, and it feels cheap. Since the volume will be controlled via the knob on the face of the radio, I want it to have a satisfying solid feel to it when turned, so I want to replace the one on the Amp board with a better made one. It would also have to be wired to the amp board but not sitting directly on it since the original knob location for the radio face does not line up with the new circuit board.
    I would really appreciate suggestions on what potentiomer to use as a replacement that would work with this board, and also have a quality feel to it. I don't have any access to local places that sell them so it's impossible for me to judge the quality of them online.

    2. I would like to wire both the both the amp and the bluetooth reciever to run from the same power source so that when the cabinet it plugged into the wall socket it will only need one power cable.

    This second part is not that important at this point because one, I don't have a specific bluetooth reciever picked out for this project, and two I haven't read much on how this could be done properly, so I will need to do more research. So basically, if you could tell me if this would be attainable for a novice, or if this part of the project is a stupid idea I would appreciate it.

    My main concern right now is just the potentiomer replacement so that I can get a better quality feel when turning the knob, and so that I can get it positioned correctly to match the position of the original knob.

    I know this is a lot, and I am truly a 100% novice so I really appreciate any input from you all. This was one of those "good ideas" that ends up taking you down all kinds of rabbit holes to get finished, but I think my pop will really enjoy it if I can pull it off nicely so I'm really hoping to do it up right for him.

    Thanks for the help!
    Last edited: Sep 8, 2013
  2. Experimentonomen


    Feb 16, 2011
    You chose the worst amp ever on this planet, that amp is a pure piece of ****!! 200% waste of money!

    I bought one of these amps once, after about 5 minutes of listening to it, it had found a new home in my garbage bin, it was horrendously bad!!!

    A purchase i deeply regret still today.
  3. muleskinner

    Thread Starter New Member

    Sep 8, 2013
    I tested it before I dug into it, and I agree it's not the best. But I think it's not too bad for the application. My dad is 60, he still listens to the original radio/speaker combo in his 55 year old car and thinks it sounds "just fine", so this little thing in his den will be ok for him haha.
    Plus, at 20 dollars, if I bork it while trying to work out the wiring it's easily replaced. No sense teaching myself on a part that's expensive to replace.
  4. GopherT

    AAC Fanatic!

    Nov 23, 2012
    Then your amp selection is perfect.

    Also, if you're used to listening to a favorite selection of music through a bad system, then suddenly change to a modern system with simulated surround or studio-like bass, then the song just doesn't sound right any more. My mother traded her old ford escort for a new honda civic with a great stereo, all I heard from her is, "that radio makes all my songs sound weird."
    #12 likes this.
  5. muleskinner

    Thread Starter New Member

    Sep 8, 2013
    Anybody have any ideas on this? Thanks so much.