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, April 10, 2018

Boss DS-1 with Keeley Ultra Mods

Got a request for the classic DS-1 with some Keeley mods and since my earlier DS-1 layout doesn't have board mounted pots, it seemed like a good idea. The flip-flop switching has been removed. Here's the schematic for reference.


16 comments:

  1. Brutal!
    The switch should be SPDT, no?

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  2. Is the switch in the layout to switch between the modded DS-1 and stock DS-1 . Switch is SPDT on-on?

    Thank you.

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  3. I bet it is supposed to be only sw 2 and 3 to choose between symmetrical or asymmetrical clipping. so it is correct using SPST. so the sw 1 shouldn't be there.

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    Replies
    1. Nah, it's a typo. Should be an SPDT on-on.

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  4. For Dual Opamp I'm thinking to use the LM358
    Its that ok?

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  5. Congrats for all your hard work! This is just awesome. Last week I was thinking of building the DS1, but the stock model is too cheap and not interesting enough to replicate... Can't wait to build this one w/mods!
    I have a request (if doable and you find time to do it, of course)... Would it be possible to do the chorus/rev section of a Rockman X100 in a stompbox format? I've unsuccessfully tried to find this in several forums and websites. While the dist/OD section of the Rockman has already been cloned (e.g. ROG's Mockman), that chorus-reverb stage is pretty unique, very coveted and, as far as I know, not replicated yet.
    If interested, I've been gathering patent docs, pictures and schematics for some weeks, but I'm afraid I lack the skills to properly read into all this info...
    Thanks again for your website and amazing efforts.

    Cheers from Spain

    Alex

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  6. hi everybody
    i,ve been trying to build this one, but i cant get it running!
    when i plug the dc power in, i get a very distorted signal, but after a few seconds the signal is nearly = 0!
    seems like iḿ loosing power somewhere after a short while.
    ( it could also be, that i have an error in my self etched pcb! )
    if anybody buildt it successfully, please let me know!
    thanks again for your great work

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  7. From layout, Q3 has no bias voltage, you should connect R 1M between Q3 pin B and Vb 4.5v (The orange line).

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  8. Since, this is unverified and people seem to be having problems, I thought that I would check the layout against the schematic published by Phillip Bryant before populating the board.

    Now I may be being stupid, but having decided to start with the dual op-amp pinout, I cannot match most of the pins on the layout to the schematic.

    I am assuming that the 8 pins for the kind dual op-amp used here (TL072 etc…), when seen from above with the notch at the top, run:

    - left side top to bottom = 1 through 4
    - right side bottom to top = 5 through 8.

    In which case, I can agree pin 4 going to the negative earth and pin 8 to positive 9V, but cannot match the other 6 pins between the layout and schematic.

    Per the schematic pins 1, 2 and 5 should be connected together, but the layout has pins 7, 6 and 3 connected. The schematic shows pin 3 connecting to the 1N4148 diode and 20K resistor, whereas on the layout it is pin 5 that is so connected. Per the schematic pin 6 should connect to a 100K resistor, but on the layout it is pin 2 that does this. Finally, per the schematic pin 7 should connect to the 1K5 resistor, but the layout has pin 1 so connected.

    It appears that when compared to the schematic, on the layout:
    - pin 1 has become pin 7 and visa versa
    - pin 2 has become pin 6 and visa versa
    - pin 3 has become pin 5 and visa versa
    - pin 4 is in agreement
    - pin 8 is in agreement.

    I cannot explain the above in terms of simply reorienting the chip north-south, flipping the chip over = mirror image, etc… Is it me? Am I doing something stupid?

    I do not have the software to easily change the layout and I have already etched one board, so I may just cross wire the socket to the board to make the above pin changes and see how that goes, but I need to also check the rest of the schematic first.

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    Replies
    1. Dual op amps are 2 op amps in one package. Like you said, pin 4 is ground and pin 8 is power. Pins 1-3 are one op amp (pin 3 the positive input, 2 the negative input, and 1 the output), and pins 5-7 are the other op amp (pin 5 the positive input, 6 the negative input, and 7 the output). These 2 op amps are identical. So using swapping sides of the chip isn't going to make the circuit not work. I did that to make it easier to lay out.

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  9. Thanks, for the information (and the great site). I am glad it is not a problem, just me being dumb.

    I only recently started making guitar effects again. The first time being when I was a kid, nearly 50 years ago. There were no ICs then, the most complex 'solid state' device being a transistor. So plenty of stuff to learn and re-learn. I just assumed that in real world applications there must be some difference between op-amp A and B, although logically there is no reason for this.

    I will try and get one of these completed this week.

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  10. Built and working.

    I do not have a Keeley Ultra modded original DS-1, so I cannot guarantee that it is a faithful reproduction, but I do have an unmodified Boss DS-1, which was purchased in used condition about 30 years ago. Compared to my old DS-1, this has:

    - much more bass (the result, I guess of the larger capacitors)
    - a significantly greater output level (12 o'clock is already well above unity)
    - more gain/distortion on tap.

    It sounds less fizzy/tinny than the unmodified unit and switching in the second red LED gives serious clipping.

    As it was unverified, I built it used the cheapest components in my parts bin, mostly Chinese in origin, including FR2 board, some 1u ceramic capacitors, 2N5088s with an hFe of only about 280-300 rather than the more typical 500-550 and an IC that is probably not even a genuine TL072, although it is so marked. Yet, it still does not sound bad. I think it would be worth a build with good quality components and then trying out with some better quality transistors and a range of genuine ICs.

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