Home Forums Help/Technical Questions Need help soldering Small Stone wires

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  • #79061
    Javo
    Member

    Hello you wise people arround EH, recently i recibe as a gift an old trashed Small Stone wich i`m trying to bring back to life, the SS came without footswitch and the color switch`s wires unsolded.

    Also i realize that someone in the past reesolded a couple of wires (thin ones, red and white) as a repair or modification.

    The case is Type III but the schematics i have found on the web (j issue) are diferent to the one i have (pcb only marked as EH FK).

    One diference is that j issue has 5 ic, and mine (“FK issue”) only one.

    I cheked the parts with a multimeter and seems ok.

    Does anyone know where i can find schematics and/or layouts of this “FK issue” SS ?
    I realy want to fix this SS, any help welcome.

    Thank You.

    Javo

    #101927
    The EH Man
    Moderator

    Not sure what that is but it’s NOT a Small Stone. Can you post a pic of the back of the circuit board?

    #101928
    Javo
    Member

    Thank for fast response!
    Here is the back of the pcb

    #101929
    The EH Man
    Moderator

    What’s the number on the IC?

    #101930
    Javo
    Member

    It reads: HE, FK, 183, thats all

    #101931
    The EH Man
    Moderator

    The IC is on the component side in the middle of the board.

    #101932
    Javo
    Member

    It`s hard to read it but i think the ic reads:
    Upper part —MC145HE
    Lower part —7726

    #101935
    Javo
    Member
    Quote:
    It`s hard to read it but i think the ic reads:
    Upper part —MC145HE
    Lower part —7726
    #101936
    The EH Man
    Moderator

    Probably MC1458E.

    I’ll see if I can come up with something for you.

    #101937
    Javo
    Member

    Thank You EH Man,
    Javo

    #101985
    The EH Man
    Moderator

    I’m pretty sure what you’ve got there is a Hog’s Foot bass booster. The switch is for power on/off.

    #101993
    Javo
    Member

    Yesterday i took the pcb under a glass magnifier and diferent types of ligth, i am all shure now that the IC numbers are: MC1458N, 7726.

    Surfing the web I found a Dr. Q. schematis wich match 99%, (a sligth diference in the way the IC is connected), i solder the bass switch, and the output as the schematic, but the unit makes a loud bzzz, like short circuit, but moving the internal trim makes a wha type of noise.

    The schematic is from a company that sells proyects so i hope is rigth.

    I will test againg the parts, i am a poor soul trying to understand electronics.

    The wierd thing is that the case is from a Small Stone, don`t know how/when it was changed.

    Thank you nice people.

    javo

    #101995
    The EH Man
    Moderator

    You know, if I had remembered the trimpot I would’ve said Dr. Q. You’re right. It’s a Q.

    I don’t think I have any empty DR. Q cases but I’ll check. I might have a Small Stone board.

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