Home Forums GuitarPCB Build Support Boogie 57 – First Kit Build (solved)

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  • #13836
    wilkie1
    Moderator

    Maybe it is time to remove the transistors and reflow all solder joints.

    #13837
    Barry
    Keymaster

    Since what you described sounded like unbiased transistors and since your bias did not help I agree that would be my next step. As Wilkie says remove the transistors so as not to heat them up and take your iron tip and touch each joint and re-flow the solder. This will insure you have a great solder joint at every location.

    I would mark each transistor with some tape so you can put it back in its previously tested space. Then be sure to re-bias again.

    #13838
    TK51508
    Participant

    10-4.  That will be tonight’s after dinner project and I will report back.

    #13839
    Barry
    Keymaster

    For reference. I just made this up for the updated 2020 Build Document.

    #13841
    TK51508
    Participant

    ok no luck.  So what I am going to do either tomorrow or Friday night….likely Friday night… I am going to remove all the hookup wires and recreate them with longer versions.  When I had this all plugged into all the pots in the black box, some of the cables were stretched out as far as they can go.  There is a possibility that the wires are bad or broken, so I need to make new longer ones to verify.

    2 questions….

    #1.  When using Sn60/Pb40 solder, it leaves the small amount of liquid material behind.  I assume that is flux.  How do you clean that off the board?  Just a toothbrush?

    #2.  I assume that there is not a way to “test” the board to make sure it is assembled correctly?  Other than checking the Q voltages?  I also assume since we discussed that I need all the pots attached or I would have an open circuit. It is not possible to test the board with ONLY just V+, G, In and Out attached?  I just was trying to understand if there was a way to verify that I had the board correct and my issues were something else.

    #13845
    Billy
    Moderator

    If you look at the schematic from a join the dots point of view from IN to OUT pads you can see for example if you leave the volume pot out there would be no connection to the OUT pad creating a gap and an open circuit so you need to connect it all up as in the build doc

    There are other troubleshooting methods like using your meters continuity check

    Without doubt the best troubleshooting method is audio probing where you simply trace your audio through the circuit then come to a point where you get distorted  audio and find your problem area

    It’s basically a logical process of illimination

    Yes that’s flux most folks use a toothbrush and isopropyl alcohol to remove it

    Your build from what we can see looks correct I wouldn’t advise removing anything until we suspect it may be a problem you can dismount your pots they don’t need to be mounted in your test rig just wired to the circuit

    Did you get all of your components with the kit I’m assuming you got it from Bruce at Pedalpartsandkits which would tell us your 2n5457s and everything else is good

    Also make sure your transistors are securely mounted in their sockets and check you have the correct value pots in the right place particularly your B1M gain pot

    I think you should post a picture of where you are now so that we can easily see all your wiring connections

     

     

    #13895
    TK51508
    Participant

    Billy….

    So here is what I have done over the last few days.  Picture at the bottom…. I pulled ALL the wires off of the board and 3PDT board because they were very short and I thought it would help to make new wires.  So I made ALL new wires that were 5 inches each with new solid core wire.  No change at all.  I then decide to remove the 3PDT board and take a separate switch I had and wire it directly in to see if possibly the 3PDT board was a problem.  Again no change.  I get clean guitar sound in bypass mode, but when I hit the switch I get nothing.  If I mess with things long enough I can get a “sound” of the engaged side.  But nothing usable.

    So I dug out an old audio probe that I had from many years ago…. and of course… I broke it.   I am going to order another female plug so I can make another one.  But for now, I have to wait on trying the audio probe for the key part to get here.

    And to answer your question… yes this is a kit from pedalpartsandkits.com.

    When I made my new wires I verified that I had the correct values for each pot.  I also was able to test each pot.  When I mentioned that I got a “sound” with the switch engaged, I was able to get enough of a noise to turn the pots enough to try to tell if they functioned… and I DID get results out of each pot.  So I feel like the pots are correct.

    I got super frustrated the other night until I dealt with the issue I was having with trying to fit 22 gauge wire into the board holds, so I was afraid I had ruined some of the connector holes.  I ordered new 24 gauge wire and things fit much easier now.  Just in case I did screw up the board I went ahead and ordered another Boogie57 PCB from Barry.  It is in pre-shipment with USPS so hopefully, it is here later this week.  So when you look at the board solder joints, I realize they look like crap because I have added and removed them over and over white testing and trying different things, plus other frustrations have left those joints not looking too great and I am aware of those.

    So here are two pictures from this weekend.


     

     

    #13911
    TK51508
    Participant

    We have success!!!!

    What we learned today is the audio probe method is the best manner of troubleshooting.

    I got the parts today to build a new audio probe, which I did.

    The first test was the drain of Q1…. sounds find.  Q2 drain sounded horrible.  In fact, it sounded like the horrible output I was getting.  So I adjusted the trim pot of Q2 until the audio probe output sounded like I thought it should.  Too low or too high got no sound, but I was able to find the sweet spot on the trim pot.  I then followed around to Q3 and Q4 and did the same thing.  Once I had adjusted all of the trip pots to where things sounded like I was expecting, I plugged into the amp and the pedal sounded great!!  Just like it should.

    Here are the NEW voltages that actually made the pedal sound correct.

    Q1: 5.01
    Q2: 4.2
    Q3: 3.9
    Q4: 4.9
    Q5: 8.9

    What I learned is that even though the instructions say put all Q voltages at a certain number, the audio probe helped fine-tune the true numbers.

    So now I am going to work on putting the unit in the enclosure and seeing if everything continues to operate.

    Thanks to all who contributed suggestions on what to look at.  Now I know what to look for if my second build has a problem!

    #13912
    Billy
    Moderator

    Great glad to hear it’s working

    FETs even from the same batch can sometimes vary wildly the drain voltages are more or less a guidline where the majority would bias up fine I always bias transistors by ear

    FETs being fickle beasts I usually get within the specified range then bias by ear till I get something I like

    Anyway troubleshooting’s always good for learning you’ll be less frustrated next time……maybe!

     

    #13927
    Barry
    Keymaster

    Excellent!

    It  a real heavy beast all on its own isn’t it?

    I hope everything arrived OK and lets see the next one. Audi Probes rule!

    #13928
    TK51508
    Participant

    Now a recommendation question…..

    I got the unit boxed up and it still works!!  So great success.  Now I have to figure out how people design and print their cool graphics.  One-step at a time though.

    But the recommendation I want is this…. if I wanted to change the value of a few of the pots, which direction should I go?  For example the gain pot.  It is a B1M.  I feel like as a B pot, a 1/4 knob turn, and the gain is all the way up.  I would like a smoother approach to 100%.  Even the tone pots don’t give me the increase/decrease I like.  So the question is…. what directions would you go with if you wanted to experiment with different pots for different results?  Different B value, change it to an A1M, or down to an A500 or A250?  Just looking for ideas from the pros.

    Thanks as always!

    #13929
    Barry
    Keymaster

    From the right-hand side bar:

    You can use any art program to design the art to print that suits you.

    #13930
    Billy
    Moderator

    You can use an A1M for gain which will give you a more gradual increase some layouts have an A1M as the gain pot obviously remove your wires at the pot and not the pcb end if you decide to try it

    I’d play around with the tone pots I’ve read if you scoop the mids it makes a difference and of course your amp settings will make a difference also

    There’s some info here with regard to the tone stack

    https://www.diystompboxes.com/smfforum/index.php?topic=97558.0

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