Sunflower Issue(s)

joelorigo

Well-known member
This pedal might might have a few problems but first:

When the pedal is activated, the LED lights up faintly, then when playing the it lights up brighter. So if you play something it illuminates and fades as the sound fades.

IMG_4817.jpg IMG_4818.jpg
 
It’s modded to be powered by a battery only. I saw this thread before I started mine:


I know that’s what Analogman does on for his Sunfaces - battery power and recommends a carbon battery.

Since I don’t really know what I am doing, I contacted the OP of that thread and he has been nice enough to guide me and sent me wiring diagrams and photos of his finished pedal. He also had a few more tweaks to more match Analogman. I just tried to copy him.

Is my audio out jack grounded? I don’t know because I don’t understand enough to tell you. One lug is wired to the footswitch (the pad to the right of the OUT pad) and the other is wired to the PCB (the pad right beside the LED K pad, short black wire).
 
Here's an update:
I took out the transistors and put in 2 AC125 ones and the LED is illuminated when the pedal is turned on but still has a bit of flickering. It also sounds more like I was expecting based on my previous GE fuzz experiences.
 
Here’s another update.
The battery I had been using was a couple of years old, testing in the “good” range. I bought a new one and tried it and the LED acts normal. Comes on and doesn’t fade or brighten when playing. So it looks like I’m all good here. But could all of this been from an older, but still good battery?
 
Hi, I'm still interested in getting to the bottom of this for my personal knowledge. Can anyone offer knowledge as to why these things happened? Changing the transistors affecting the LED? Then the battery?
 
When batteries run low on charge, they sag under load, any kind of load. Your DMM does not load the battery and as a result, you might get the impression that the battery is in good condition when it's not. If you want to test a battery, it needs to be loaded to get an accurate result. At the very least, measure it while it's connected to a pedal and the pedal is engaged.

When you run sound thru a pedal, the battery current will likely change. Depends on the circuit. Opamps tend to draw a pretty steady current in most circuits. Discrete transistor designs like the Sunflower have variable current demand, depending on the bias and fuzz settings, playing style, etc. This caused the battery voltage to sag a variable amount while you were playing.

The LED is powered by the battery and when the battery voltage sags, the LED current goes down and consequently, the brightness goes down too.

Some people prefer the "dying battery" sound in certain pedals. The Fuzz Factory's STAB control can simulate an extreme case of battery sag.

FYI, in a lot of pedals the LED draws more current that everything else in the pedal. To help preserve battery life, disengage the pedal when you Take 5.
 
When batteries run low on charge, they sag under load, any kind of load. Your DMM does not load the battery and as a result, you might get the impression that the battery is in good condition when it's not. If you want to test a battery, it needs to be loaded to get an accurate result. At the very least, measure it while it's connected to a pedal and the pedal is engaged.

When you run sound thru a pedal, the battery current will likely change. Depends on the circuit. Opamps tend to draw a pretty steady current in most circuits. Discrete transistor designs like the Sunflower have variable current demand, depending on the bias and fuzz settings, playing style, etc. This caused the battery voltage to sag a variable amount while you were playing.

The LED is powered by the battery and when the battery voltage sags, the LED current goes down and consequently, the brightness goes down too.

Some people prefer the "dying battery" sound in certain pedals. The Fuzz Factory's STAB control can simulate an extreme case of battery sag.

FYI, in a lot of pedals the LED draws more current that everything else in the pedal. To help preserve battery life, disengage the pedal when you Take 5.

Great thanks! It's great to learn from other on this board.
 
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