MXR Phase 45 clone

[jugglindan]

Note, Vp is actually negative. I adjusted my labels but in the photo above I have just written the value as seen on the multimeter.

I was also happy to see that the batch of 10 J201s I bought cheap on eBay were all within spec.

[jugglindan]

And finally, the 3 matched pairs give me some choices for tuning the sound as well since they all have different expected gain. So I will socket the board and try each of the 3 pairs (and maybe the other FETs when they arrive) to pick the ones that sound best in the circuit.

[jugglindan]

On the last two stripboard builds I used two different methods to make the cuts in the copper traces. On the first, I marked each cut from the top of the board then drilled out the holes. This worked reasonably well, particularly because the Guitar FX Layouts diagrams only show the cut locations from the top of the board. I also found that having larger holes visible from the top of the board gave some extra landmarks for locating components.

On the second build, I used a stripboard cutting tool to cut traces by hand. This requires marking the location of each trace on the copper side. I did this by mentally flipping the top-side cuts diagram. I got it right but that board was simple and on something larger the risk of mistakes is high.

So now I tried something different again. I made a copy of the cuts diagram, reversed it in a photo editor, resized to the exact dimensions of the board and printed it.


I then taped it onto the board, using wire punched through the paper on two cuts as locators to get it all lined up. A sharpie then soaked ink through the paper to mark each cut.


I got a nice result, and triple-checking showed all the cut locations were right:


One episode of B5 later, and I have a circuit board:


Once I get to this stage I always test for continuity across each cut and adjacent tracks. Sometimes tiny traces of copper remain, or threads of copper get dislodged during cutting and this can be enough to create shorts.

On my next build, I will probably use a hybrid of the first and last methods. This process was a faster and easier way to locate all the cuts, but I still miss the landmarks that larger holes provide. Cutting by hand takes a while too. So I might skip the image flipping and instead tape the actual size printout to the top of the board to mark the cuts, then drill through.

[jugglindan]

Links done, but too tired to start populating with resistors. That can wait.

[jugglindan]

Good run tonight watching B5. Board done apart from socketing the JFETs and op amps. I am still waiting to see if the 2N5952s and TL072s arrive in the post, or if I have to substitute J201 FETS and 4558D op amps. At top-right there is a socketed resistor. There is a mod that adjusts the value of this resistor to create an intensity control. I have socketed the stock value, and once the circuit is working I can try other values or wire in a pot if I like the effect.

[jugglindan]

Two designs mocked up in Inkscape (yeay v1.0 )


Leaning towards the first, since it is a phaser pedal, but I just like the idea of a pedal with a "warp factor" knob.

[Woltz]

Two designs mocked up in Inkscape (yeay v1.0 )


Leaning towards the first, since it is a phaser pedal, but I just like the idea of a pedal with a "warp factor" knob.

Tough choice. What about modifying the design to have the phase pistol shooting?

Or if you do starship then what about having it as it's engaging warp to illustrate movement?

Haha or ignore me, I just like toying with ideas.

Sent from my SM-G960F using Tapatalk

[jugglindan]

Tough choice. What about modifying the design to have the phase pistol shooting?

Or if you do starship then what about having it as it's engaging warp to illustrate movement?

Haha or ignore me, I just like toying with ideas.

Sent from my SM-G960F using Tapatalk

Do mean move the LED to the appropriate location? I could try a mock of that.

Also thinking of keeping the Enterprise version for a drive pedal. I am planning a 2 knob red llama so I could label the knobs impulse and warp.

Sent from my moto g(7) using Tapatalk

[jugglindan]

Tough choice. What about modifying the design to have the phase pistol shooting?

Or if you do starship then what about having it as it's engaging warp to illustrate movement?

Haha or ignore me, I just like toying with ideas.

Sent from my SM-G960F using Tapatalk

Here's a mock of how the LED as shooting phaser might work:

[jugglindan]

It's a shame the red llama doesn't have clipping diodes. I could use red LEDs and run them to the enclosure. Then the engine would light up as you play harder.

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