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Thread: Preamp question

  1. #1

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    Preamp question

    Is there a way of knowing what year this stingray preamp is? I've had it for years and might use it for a project. I'm assuming it's from mid 80's or early 90's? Cheers

    Preamp question-mm-stingray-preamp-jpg

  2. #2

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    Do you have a larger pic which includes the full length of the leads.

    PS: and the reverse of the board.
    Last edited by Rod Trussbroken; 08-27-2021 at 05:50 AM.

  3. #3

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    Quote Originally Posted by Rod Trussbroken View Post
    Do you have a larger pic which includes the full length of the leads.

    PS: and the reverse of the board.
    Cheers Gav. There are non original pots attached to it. Let me know if you need anymore pics.
    Attached Thumbnails Attached Thumbnails Preamp question-mm-stingray-preamp-2-jpg   Preamp question-mm-stingray-preamp-3-jpg  

  4. #4

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    Above is a 1985 Ernie Ball 2EQ Sting Ray preamp.

    Your preamp is also a 1985. Note the 3 grey and 2 blue electrolytic capacitors. Putting aside capacitor colours, it's the same as a Pre-EB preamp from c.1982 onwards. EB and Pre-EB use the same circuit boards which are designated "B3" on the underside copper track. The only difference between EB and Pre-EB is that EB soldered the IC chip "LM4250CN" direct to the circuit board. The Pre-EB has the IC mounted to the board via an IC socket.

    Before soldering the preamp into circuit it should really have a 1K Ohm protection resistor added to the end of the white lead-out wire (bottom right). EB included this resistor on the board in c.1986.I have the wiring schematic if you need it.
    Last edited by Rod Trussbroken; 08-28-2021 at 03:55 AM.

  5. #5

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    Quote Originally Posted by Rod Trussbroken View Post


    Above is a 1985 Ernie Ball 2EQ Sting Ray preamp.

    Your preamp is also a 1985. Note the 3 grey and 2 blue electrolytic capacitors. Putting aside capacitor colours, it's the same as a Pre-EB preamp from c.1982 onwards. EB and Pre-EB use the same circuit boards which are designated "B3" on the underside copper track. The only difference between EB and Pre-EB is that EB soldered the IC chip "LM4250CN" direct to the circuit board. The Pre-EB has the IC mounted to the board via an IC socket.

    Before soldering the preamp into circuit it should really have a 1K Ohm protection resistor added to the end of the white lead-out wire (bottom right). EB included this resistor on the board in c.1986.I have the wiring schematic if you need it.
    Awesome. Thanks Gav, I appreciate it. Could you please send me the schematic? Thanks again.

  6. #6

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    Quote Originally Posted by Rod Trussbroken View Post


    Above is a 1985 Ernie Ball 2EQ Sting Ray preamp.

    Your preamp is also a 1985. Note the 3 grey and 2 blue electrolytic capacitors. Putting aside capacitor colours, it's the same as a Pre-EB preamp from c.1982 onwards. EB and Pre-EB use the same circuit boards which are designated "B3" on the underside copper track. The only difference between EB and Pre-EB is that EB soldered the IC chip "LM4250CN" direct to the circuit board. The Pre-EB has the IC mounted to the board via an IC socket.

    Before soldering the preamp into circuit it should really have a 1K Ohm protection resistor added to the end of the white lead-out wire (bottom right). EB included this resistor on the board in c.1986.I have the wiring schematic if you need it.
    Cheers Gav. Much appreciated. Could you pls send me the schematic? Thanks again.

  7. #7

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    Travis is that you?

    I bought one identical to that from a guy named Travis lol
    Last edited by kevins; 09-01-2021 at 04:59 PM.

  8. #8

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    Quote Originally Posted by Rod Trussbroken View Post


    Above is a 1985 Ernie Ball 2EQ Sting Ray preamp.

    Your preamp is also a 1985. Note the 3 grey and 2 blue electrolytic capacitors. Putting aside capacitor colours, it's the same as a Pre-EB preamp from c.1982 onwards. EB and Pre-EB use the same circuit boards which are designated "B3" on the underside copper track. The only difference between EB and Pre-EB is that EB soldered the IC chip "LM4250CN" direct to the circuit board. The Pre-EB has the IC mounted to the board via an IC socket.

    Before soldering the preamp into circuit it should really have a 1K Ohm protection resistor added to the end of the white lead-out wire (bottom right). EB included this resistor on the board in c.1986.I have the wiring schematic if you need it.
    How likely is the preamp to blow without it anyways?

  9. #9

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    Quote Originally Posted by kevins View Post
    How likely is the preamp to blow without it anyways?
    The resistor is to protect the preamp IC from being destroyed if the guitar lead becomes short-circuited (even momentarily). Easy to happen.

    All MM Sting Ray and Sabre Basses have them factory-fitted. Initially they were an outboard component. They became an on-board component c. 1986. The above 1985 preamp doesn't have the resistor on the circuit board. It, and earlier preamps will have to have it added manually.

  10. #10

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    Quote Originally Posted by kevins View Post
    Travis is that you?

    I bought one identical to that from a guy named Travis lol
    Lol, nope. Not me. My name is Ray

  11. #11

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    Any chance you wanna sell that one?

  12. #12

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    Quote Originally Posted by kevins View Post
    Any chance you wanna sell that one?
    Sorry mate, I'm using it.

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