Knight Rider fuzz

3/6/2014

A Roger Mayer Moongoose fuzz that I built inside an old powersupply box. For the gain pot I used a fader that I salvaged from a broken small mixer. I also added a LED VU meter that I originally built for a mic preamp. It's not really useful, but a fun gimmic. :) Here's a video (pardon my sloppy playing)... :)

Here's a vero layout I made for the LED meter circuit

4 Comments

agung setiadi zainal abidin

10/23/2014 06:55:26 pm

Hy fredrik
Maybe V in doughterboard must be to SPDT pin no 2 (SW2), SW1 to SPDT pin no 1, and SW2 to SPDT pin no 3..please help me

Thanks

agung

Fredrik Lyxzén link

10/23/2014 08:26:01 pm

Hi Agung
There is only need for one switch. SW1 and SW2 on the board indicates the lugs on the same SPDT and it controls the mode of the meter. Sorry, I should have made that clearer. In one mode all LEDs below the meter level stay lit up, and in the other mode only the led that shows the current level lights up. +9v can be connected directly to the daughterboard and neither the boards needs to be connected to the bypass switch of your pedal. I hope that helps / Fredrik

bongfart

1/30/2022 03:38:34 am

hello. I tried to build this and while it works, it adds unwanted character to my fuzz and I can hear the clicking of the LED as it ramps down (trying to add on an npn fuzz face). It also seems to emit the first led permanently when in dot mode. I am adding the input on the circuit above to the input on the board of my circuit. am i doing this wrong and how can I wire it so it has no affect on my signal? and how would I stop the first LED from emitting while the rest do their job?

Fredrik Lyxzen link

2/3/2022 07:58:39 am

Hello,
The datasheet recommends a 2.2uF capacitor on the anode side of the LEDs (as close as possible, on the LED strip) to ground, to minimize noise via the power rails. You also probably want to add additional DC smoothing capacitors to your effect board aswell and keep the effect/sound board as far away from the LED driver board as possible in the enclosure and make sure that no wires crosses the LED driver board.

R3 and R4 creates the voltage reference to the LED bar, so to turn off the first LED you want to adjust either of the resistors. Not sure exactly how, so it's probably best to socket one of the resistors and try different values there. You could also remove those resistors completely and wire up a 5K or 10K trimpot instead (wiper to row H where both resistors meet).

I hope that helps
/ Fredrik

Knight Rider fuzz

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