This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Tuesday, June 30, 2015

Electro Harmonix LPB-1 (and its siblings)

The LPB-1 was the first effect made by Mike Matthews and Electro Harmonix. Like many other effects at the time, it was housed in a small box that plugged directly into your guitar. It was designed to give you a volume boost and push the amp into overdriven territory. EHX still makes the LPB-1 (Linear Power Booster) to this day, as well as its sibling circuits, the Screaming Bird (also known as the Screaming Tree) treble booster and the Mole (also known as the Hog's Foot) bass booster. The LPB-1 and Screaming Bird/Tree can be built on the same board, as the only difference between the two is the input and output capacitor values (100n for LPB-1, 2.2n for Screaming Bird/Tree).


The Mole/Hog's Foot is basically the same circuit, again with differing input/output caps. However, there are 2 added 100n capacitors that make it necessary for a different board.



23 comments:

  1. "Volume 2 to Out" --> What is the meaning of this? Is the meaning of that is ---> Volume potensio Pin No.2 goes to 3pdt switch pin?
    Anyone who know, Please help me? thanks

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    1. That's correct. In a lot of effects the circuit output is from lug 2 of the volume control. Check out the General Layout Notes for offboard wiring diagram.

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  2. Hello, how i should to connect the wire to led? because in your general layout notes it is just connected to the 3pdt switch. I hope you can help me :)

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    1. Wire the LED pad to the anode (+) of the LED, then wire the cathode (-) to the switch like in the General Layout Notes diagram.

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  3. https://www.youtube.com/watch?v=Mm_oQzdrtFI&feature=youtu.be
    lpb1 + muff fuzz(transistor ver)

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  4. Hello guys. Great page, I like it because it's very simple for begginers like me. But I have one question.. how do i know what transistors and diods to use, not only for this project but othera as well? Other than that almost everything is clear. Thanks a lot.

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    1. The transistors are listed below the layouts. In this case the transistor (Q1) is a 2N5088.

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  5. Hi! The Mole Hog's Foot is verified? The pcb is ready to print? Or i have to flip it? Thanx!

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    1. To my knowledge it hasn't been verified, but it should work (I'm pretty sure the LPB-1 has been verified come to think of it). It's ready to print. A scaled pdf can be found in the Transfer Image Library tab at the top of the page.

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    2. Thanx! I want this booster for my bass. You know another booster for bass? Sorry for my questions. Im very noob in this.

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    3. The Catalinbread Sagrado Poblano Picoso is a good bass booster.

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  6. can i replace the 390R resistor connected in emmitter? and what values can i replace that??
    tia

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    1. you can use the 330R, or you can use the 330R in series with 47R resulting in 377R that will be almost equal to the original value.

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  7. works perfectly, recommend using the original transistor, can mark as verified and approved.
    thanks again!!!

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  8. Hey, how do I install this on my bass guitar? And how can I omit the volume pot?

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  9. @Effects Layouts, I've built this and really is a good volume boost. I made one for my friend and he says, it does boost volume very well but too much low freq is passed and almost no highs are left in the signal. Sounded too full. Too much, that's what he says. What values do you suggest I should replace the resistor and the 100n caps? The one from +9v to collector and the other that goes to ground?

    Thanks.

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    1. Replace the two 100n caps with lower values. Use some sockets to audition different values.

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    2. Okay so now they tried it on a bass with active pickup. Doesn't work, but works well with bass with passive pickups. How come?

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    3. @Effects Layouts I meant the EHX Mole.

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  10. I created a stacked Mole, with option to remove/adjust high cuts to get a stacked LPB-1 which doesn't attenuate bass on input/output. Been great on my bass, good on guitar too.
    https://www.annabellekhoo.com/2023/03/24/the-deep-double-boost-pedal-for-bass-2n3904-build/

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  11. LPB works great. I can verify it. I used it for my Blue Box, works like a charm!

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