The 15W Fender Squier guitar amplifier
Finally, I noticed that a slight pressure on the PCB (printed-circuit board) made the sound cut in and out, meaning that I had done a bad job on soldering the joint on the gain potentiometer. Once I fixed that problem, the weak volume and buzzy noises disappeared.
1. I found that two of the potentiometers were broken in half and the rest were scratchy and intermittent—not good. I replaced the no-name cheapos with genuine Bourns units. You can see, feel, and hear the quality improvement.
2. The carry-strap screws secure the chassis inside the chip-board enclosure. Two tabs secure the lower part of the panel.
3. One of the common mistakes mechanical engineers make is using electrical components to carry structural loads. The potentiometers should not have to support the whole PCB.
4. Thanks to my poor soldering job, I had to yet again pry the PCB apart to find out why the sound was intermittent.
5. I had to cut down the shaft and grind off the antirotation lug on the replacement potentiometer on the right.
- Op amp guitar amplifier
- The quest for the perfect guitar tone
- Analog lives in the guitar pedal stomp box