Home Forums GuitarPCB Build Support Blues Buster drive (answered)

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    I am testing the circuit before I box it… I’m not getting any action out of the drive pot. It sounds like maybe it’s up all the way (since there is some nice, healthy gain), but it doesn’t react to the pot. I can measure the pot and see it changing (but in the circuit, it’s got a strange value probably due to the parallel resistor, among other things).

    However, I also haven’t installed the switch (I ordered the wrong thing), and it sort of looks like the switch might be connected to the drive pot in the schematic– but I don’t know about these things. it is possible that the missing switch is messing with my drive pot?



    Per the schematic shown above you are incorporating clipping options of D1, D2, D3 & D4 or just D5 and D6 with the switch. See arrows.

    That said I would finish the build first before going 100% on a Troubleshoot.

    Additionally I would expect your guitar to have high output pickups based on the critique of this circuit and the Overdrive circuit in the other thread. This can easily be tested by plugging in a guitar cord to your guitar and testing the sleeve and tip of the other end with your Multi-Meter to get the readings from your pickups. I use vintage wound pickups always (all 8k or under) and easily get a wide variety of Drive & Clean tones. If your pickups read 10k output or higher I would not expect to easily achieve as many clean tones. The guitar essentially is part of the entire circuit.

    If you find after testing the output of your pickups that they are vintage wound and you still have way too much Drive then it is likely a build issue and you should begin troubleshooting.


    Thanks Barry,

    I appreciate the encouragement.

    I did measure my pickups… neck = 9.95K, bridge 9.5K, together 4.43K. This is interesting, but I’m not sure what it’s telling us. It looks to me like this is measuring my guitar pots?

    I do understand (to an extent) about the different pickups. I play on modern humbuckers. My friend (who will share in the spoils here) uses a semi-hollow bodied telecaster, but also has a solid body with custom wound humbuckers. and we haven’t demoed on his rig yet. so… we still have a bit of experimenting to do before I fix the last solder on this circuit.

    For my needs… I don’t know what I’m looking for, I’m just experimenting.

    I didn’t intend for my comments to come across as a critique of the pcb or anything as such… I’m just making observations to assess that I’ve got the circuit right. I don’t have a lot of experience using effect pedals–much less building them. of the three I’ve got working, my favorite is the colortone OD. I may end up with two b/c I like the saturation of max gain but also the clean headroom. but I’m not disappointed the others.

    I did get a switch on the BB board. (I have to say that I love the color of the pcb–b/c it’s easier for my poor eyes to read. the lines just seem to pop out a little easier for me.) and now the drive pot IS working. however, I don’t seem to get much volume out of it. maxing the volume and I’m just a little over unity. Is that normal for this pcb or is it worth looking at my IC? I have some subs I can use.

    Yes, the pedal cleans up when I turn down my guitar volume, however, I have to turn it down pretty far (6) and I end up losing a lot of treble (which seems to happen with my guitar–not an artifact of the pedal or anything). I know a lot of players get a lot of mileage from manipulating the guitar vol pot, but that’s not a talent I’ve really developed. I do like the tone and gain structure of the pedal. I will definitely keep exploring it.



    You are testing the output (loudness) of each pickup depending on the pickup selected. Your pickups are 10K. (Van Halen range) These high output pickups act as an extra gain control feeding into your pedal so as result when you use your guitar only on 10 or full up you are limiting your “available” amount of clean tones. Fortunately the output is easily adjusted by the Volume control. The complete part of any pedal circuit starts with the amount of output being fed into it.

    I would check out some videos on adjusting your guitar volume control, tone controls and pick attack to allow you a much wider pallet of “available” control over your pedals (no mods required). If you are experiencing treble loss there is a simple mod for your guitar called a treble bleed utilizing a cap and resistor so you don’t lose treble.

    If you wish to achieve cleaner tones with your gear it is not necessary to change your pickups but it will be necessary to utilize your guitar volume (reducing the Gain of your pickup output). I am not referring to dificult manipulations similar to the swells produced by Jeff Beck but simply adjusting the guitar volume to eight, six or five depending on the desired tone and leaving it there till a change is required to broaden your overall tone.

    Here is the first Video I grabbed which hopefully will be a good start:

    I would jump ahead to 1:20 as he is very chatty.

    I hope that helps.



    Here is a good video that describes the Treble Bleed Mod I described above:


    I haven’t had a chance to try out the treble bleed mod. looks cool, but I have to remove my strings before I can access the pots. but I will try that at some point. thinking out-loud… maybe I can put that in a volume pedal to see how it works?

    In the meantime, I’ve done a bit more test driving for the BB, the overdriver circuit and the colorsound OD. I’m starting to get it now. each one has it’s own character, but they all give me a lot more usable range with my vol knob. and now that one control can be used to do more than just volume. Enjoying these a lot at the moment.



    Just finished a blues buster as well and the gain knob isn’t reacting the same way as, say the tube screaming ultra, is this normal?  Just wondering if it is how this circuit is designed or if I sold start trouble shooting.  Your input would be appreciated.  Thanks

    PS made about 20 of your pedals so far.


    @ Dice: I would be glad to help.

    Please start a new thread and give me more exact detail.


    Although the 2 circuits have similar design, the TS has a much greater max gain (@505) than the BB (@56).

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