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Thread: Motorola HS-475 project:

  1. #1
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    Motorola HS-475 project:

    So I got motivated to complete this project I've had sitting on a shelf gathering dust for many years. It came out of an old hi-fi & I've managed to relocate & add some features to make this a combo-style guitar amp: I put an ON/OFF switch on the back, moved the input jack (formerly the PHONO input) to the corner, & installed an IEC jack for the power, & relocated the speaker output jack to the front of the chassis. I also added some fancy red pre-amp tube shields.
    Next up, I am replacing the can capacitor (& a couple of resistors that are attached). After that, I am going to replace the filter caps.
    Here are a few pics of the unit. Since I can't really read a schematic very well I am just going to try & identify the filter caps & replace them one at a time. I'm guessing that they are the white cigarette butt looking things in the last picture. If anyone has any tips or advice, I'm open to hear it.
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  2. #2
    Forum Member phantomman's Avatar
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    Re: Motorola HS-475 project:

    Those white axials seem to be cathode-bypass caps.

    The cap can is the filter array.
    "When injustice becomes law then rebellion becomes duty."

  3. #3
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    Re: Motorola HS-475 project:

    You're saving me money already
    Lol
    I'm just waiting for my fancy solder sucker to get here & then its showtime

  4. #4
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    Re: Motorola HS-475 project:

    I replaced the can. It sounds so much better but not perfect. It hisses a little, & there's the occasional thunderstorm/frying bacon going on. Sounds like carbon crackling, lol
    But it's pretty punchy, & would make a great harmonica amp if you put a little slapback on it. I'm going to have some fun & make a 1x12" cab for it

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