Friday, 18 January 2013

Electro Harmonix LPB1 with trimmer

Request.  A compact LPB1 layout with a trimmer instead of the external pot which can be used as an internal booster for other effects that need a bit of a push







and if you do want an external volume control



41 comments:

  1. You Rock I appreciate it and will build tomorrow!

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  2. You can mark this one verified worked like a charm. Thanks again I really appreciate all you do.

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    1. Excellent, thanks for verifying :o)

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  3. I can see that one in the same box that the seamoon funk machine !

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  4. This was just what I needed. I put it in the Os Mutantes Fuzz that I loved the sound of but it had no volume. Now it sounds great. Thanks

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  5. Hi!
    This is my first built. I've chosen this one because I needed a boost and this looked somehow easy.
    Everything works right away - so I'm happy over this first triumph.
    But it behaves slightly different to that what I've expected: the boost produces a lot off fuzz and emphasizes the low mids. So I would rather call it a Fat Boost as Linear...
    What can I do to add a little more highs and get less fuzz? I've used 1/4W metal film resistors (1%), tantal caps (20%) and an Alpha 100k log pot.
    I've testet with 9V and 12V. On 12V it tends in the right direction. Although with my Strat it's fine a humbucker assembled guitar has to much output I guess.

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  6. Can I change the trimmer to an external pot since your other layout is on turret?

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    1. http://tagboardeffects.blogspot.com/2010/03/few-veros.html

      Or you can remove the trimmer, remove the output wire, lose a column from the left and take wires from the bottom 3 rows to an external pot.

      Bottom row to lug 1
      3rd from from bottom row to lug 3
      Then lug 2 is your new output to go to the stomp switch

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  7. Hi Mark, the value of the cap is 47uF? My second question is: can I replace the diode 4001-4004 or 4007? Thanks in advance!

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    1. I'm talking about the same pedal but for the schematics with the external pot...

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    2. The other layout with external pot has the 47u cap and diode as power supply filtering and reverse polarity protection. This one is designed to be an addon board to give another circuit a bit of a boost if required and so compactness was the important factor so it will fit comfortably in the same box, the supply will already be filtered and/or protected by the main circuit.

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    3. Oh and yes you can use any 400X diode, just be careful because the bigger numbers get physically bigger too so fitting them in the gap will become more awkward

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    4. Everything is easy when explained by the master! :) Thanks mate! I have seen that combination with cap+diode and I got it my self that its a kind of filter but another beginners question got it's answer :) Thanks again! Works and sounds grate even do I'm stunned bu the SHO and EM drive boost, this ELH will be a good reserve :)

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  8. Hi people, I just finished this and it works but with 2 disadvantages.

    1: I have a bad whine all the time

    here is a sound sample of what I mean:
    http://vocaroo.com/i/s0ItaEy1RbqN


    2: I wanted to use it on bass and it boost the signal but can't get the fuzz out of it.
    Is there a way I can get less gain out of the tranny? I tried to switch the 390 ohms resistor to a higher and lesser value, even tried to put a pot in there but still a lot of fuzz.

    Thanks in advance

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    1. Yes increasing the emitter resistor, or decreasing the collector resistor will reduce the gain, but it's hard for you to judge it properly until you've sorted out the noise which may be contributing to the fuzz you can hear. Whistling is usually down to a poor connection somewhere, so re-flow all your soldering, including the trimmer and wires to the board.

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  9. I built one of these last week. I used a 2.2k resistor on the LED. No popping in the switch, no grounding issues. It will clip with medium output humbuckers somewhat, but still fairly clean. Might just be a slightly cold solder joint. 100% pure clean on single coils.

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    1. Here's a clip using a strat
      http://youtu.be/RksT65Q_RQU

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    2. did you use the second scheme alone?

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  10. Just built! Nice boost. I put it in together with an overdrive circuit. Separate overdrive, separate boost, or together, or just boost!
    Just a little too much bass coming thru for me. How can i cut it back a bit?
    a 330r in place of the 390r on the emitter side or 4.7k instead of 10k on the collector side?
    Other than that its a great boost. Very quiet.

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    1. Changing those resistors will alter the gain of the stage, if you want to cut some low end reduce the input capacitor. Try a 47n and see if that works better for you

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  11. 47k did help! Thanks! Put a socket in it. Gonna keep tweakin it.

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  12. slight error on the external pot layout, the vero that shows where the trace cut has 9 rows instead of 8, it caused me to put the trace cut in the wrong place. I was able to move the resistors around to make it work though.

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    1. Bump. This still hasn't been fixed. I'm sure it's a common utility layout. Can one of the new contributors circle back a fix this it got me too.

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  13. Hi Ivan, I am seriously puzzled... I built several pedals including some using your diagrams (terrific job, btw) and I built the trimer version of this to use as an onboard booster in my guitar. I tested it build before mounting on the guitar and connecting to the battery delivers a tremendous amount of noise, like static tv signal on steroids. I bypassed the transistor and it works fine, but obviously with no boost. I tried reversing the transistor layout in case it had reversed lugs and I also try with another transistor of the same model. Nothing helped. The transistor code reads 2N5008 C27.

    What maybe the issue? Do I need a power supply filter? I thought that with a battery that was not necessary.

    Rechecked all solder points and continuity is correct all over the circuit. I wonder how I could screw up such a simple circuit.

    Any ideas?

    Many thanks.

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    1. Hey Pedro,
      Looks like the 2N5008 isn't equivalent to the 2N5088.
      I checked on AllTransistors.com for equvalents to the 2N5088 and I got a huge list ...
      ( http://alltransistors.com/crsearch.php?mat=Si&struct=NPN&pc=0.31&ucb=35&uce=30&ueb=3&ic=0.05&tj=135&ft=50&cc=4&hfe=300&caps=TO92 )
      But the 2N5008 was not one of those.

      I have used the 2N5088, 2N5089 and PN100 with full functionality.
      The PN100 has *huge* gain but sounds super sweet.
      So ... maybe try using one of those 3 and see how you go?

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    2. This is not a transistor Problem. I'm getting the same noise, with 2N5088, and have no idea why. Checked all the solder joints as well... so, a bad resistor? Or a bad cap???

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  14. I built several of these and they all end up having roughly the same level as the clean guitar signal, but with overdrive clipping, so no boosting. Am I doing something wrong? Have you experienced this?

    Not sure what my error is, I've checked my work front to back and compared it with the layout above and I don't see any differences. Any suggestions to increase gain/boost level volume?

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    1. Post a good pic of the front and back of your vero and we can have a look! Are these your first builds?

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    2. http://s24.photobucket.com/user/zacharylewand1/media/mail.google.jpg22233_zpstcsryngz.jpg.html

      http://s24.photobucket.com/user/zacharylewand1/media/mail.google.jpg22_zpsih0ka4n5.jpg.html?filters[user]=143727084&filters[recent]=1&sort=1&o=0

      Here are images of the front and back of the vero. Thanks!

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    3. Also - is there a specification for the 100n capacitors whether they be ceramic disc or epoxy dipped, or does either one work?

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    4. The value of the caps are whats important. Materials less so (thats a whole different discussion).

      I too have build this layout exactly as is and can tell you it have an insane amount of volume so rest assured it works when built properly.

      Your pics are very low quality making it difficult to see any issues. There does look to be some iffy looking soldering, dull solder joints, unfinished joints etc. I'd reflow all these joints for a clean, solid connection.

      I'd also check the strips for continuity with a meter. When you cut the board to size it left a very ragged edge. There may be an unwanted copper bridge.

      Lastly, you should really socket your transistors. Heat from a soldering iron can kill them and you wouldn't know they're dead until you took them out again. Sockets make this quick, easy and hassle free.

      Try the above or maybe make up a new board and just take your time. The more care you take during prep the better chance you have of a circuit firing up first time.

      Good luck

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  15. Need to trim a column from the back of compact version. I just noticed because I was building the trimmer version and replaced with pot before I saw the compact. Anyway, amazing blog. Thanks!

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  16. There is an error in the second image: schem says 8x7 but shows a 9x7 vero in the right side...

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  17. Works great! I am now in the process of adding a diode pair to the output. I haven't yet decided on which type to use. I'm presently a/b'ing 1N4003, 1N914, and 1N5243B. No big differences between the three except the slight amounts of overdrive and low mid response, at least to the ear. Ultimately, I will throw a toggle switch into the circuit to allow bypassing of the diodes. I might even do an A/B/C switch with 4 diodes option.

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  18. Hi! The booster works great! I have one question, I combined it with a Brown Sound in a Box in one enclosure, and when the gain of the distortion is above 2 o'clock I can't use the booster above 1 o'clock, otherwise I get a really annoying and loud high pitch sound.
    Any ideas of what could this be?

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  19. Hey Mark. The External Pot version needs 1 row taken off the vero at the end by the cut. Made the mistake of making a bunch of these and counting the cut from right to left. The layout is 8x7 but the vero with cut location is 9x7.

    Cheers

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  20. built one of these, wanting to join it to a vico vibe circuit i built. having a hard time wrapping my head around how that's done... i want to keep it in the existing enclosure as the vico. anybody provide some assistance please?
    thanks!

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  21. Do I need to put it before the input or after the output effect ?

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    1. Up to you. If you put it before you'll boost the signal going into the effect and slam it, if you put it after you'll boost the single after the effect and raise the overall output.

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  22. Built one of these the other day, super simple. Currently using 10R in place of a pot/trim and it sounds great!
    Plan on using it in the same box after an Orange Squeezer
    Question... how would I go about putting in a switch to change the order of effects (Comp into boost or Boost into Comp)
    is this an easy thing to do?

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