- This topic has 29 replies, 4 voices, and was last updated 5 years, 8 months ago by
.
-
Posts
-
Howdy from Texas!
So this is my very first GPCB kit build. I tried to follow the install of parts slowly and carefully. I believe I have all the parts in the correct places and the correct polarity. I can use my multimeter and get 9v at various power points. I have been able to adjust the trim pots to as close to 5v as I can get them according to the build sheet. But even with the most basic of connection….V+, G, In, Out…. I get no sound when I activate the board. Please look at my board and see if you see anything noticeable.
Thank You!!
Hi and welcome!
Usually when you have a no sound issue it is an error in the off-board wiring.
I don’t suppose you have any photos of that lying around?
Hi Barry. I can send a photo of my daughter board as I did create that while building. But I am testing with the Beavis Board box that I built for testing. As I read on Facebook and the forums here…. Rock it before you box it! So I am just trying to hook up the G, V+, In and Out from the Beavis Board to the appropriate spots on my PCB just to see if I got any sound. Which unfortunately I do not. I can take a picture of the inside of my Beavis Board box, but it is very straight forward and I do get sound when I am bypassing the PCB. So I get sound, until I hit my switch, LED comes on, but no sound.
I would really like to rule out the wiring some how as that is the most likely culprit and everything else that is less likely will take a while.
Maybe draw me how you connected it to the beavis box which would be easier in that case. You can even hand draw it for me and take a photo of that.
BTW be sure your Voltage Sag on the beavis box didn’t get bumped.
or better just reconnect the off-board wiring and hook it up to the Beavis Board and take a good photo of that. You are going to need to reconnect it anyway to take voltages and you will need to reconnect all of those pots.
Ok… I reconnected the off-board wiring. Same result. Sound in bypass mode, no sound engaged.
The enclosure you see here is a 3d printed box that I made as a test enclosure to hold everything in a bigger space that would give me room to test everything before putting it in a smaller metal enclosure.
I also know I technically have the LED wired upside down. Because of the way the 3d printed box is laid out, if I want to see the LED I have to put it in upside down. It works, just the colors are flipped.
The potentiometers are not hooked up. Just sitting in holes in the box. I can add those next if that is my next step. I just thought I should at least get sound of some kind at this point.
Hopefully, the two different photos take the glare out from the phone photos.
Also…. I found something that is a bit confusing.
On the Boogie-57 Build doc, there is THIS photo that shows the V+ and the ground going to the PCB.
But in the guide pdf called: “3PDT WIRING BOARD v4 and v5 – Common Anode LED” It shows the V+ and ground going to the daughterboard.
You will see in the wiring of my board, I did the “3PDT WIRING BOARD v4 and v5 – Common Anode LED” version.
Should I change it to the other version with 9v going right to the board?
Both images appear to be using the v5 of the 3PDT Wiring Board.
As long as you have power going to both the main and 3PDT pcbs that’s ok and if, as you’ve said you get 9v readings on the pcb that confirms you’re getting power
When you say the potentiometers are not hooked up do you mean they are not soldered to the pcb? they need to be soldered to the pcb otherwise you’ll have an open circuit
Incidentally for a first kit that looks really good and very well put together I’m assuming you’re not new to electronics?
Yes either version is correct as they are both accomplishing the same thing.
Potentiometers are variable resistors. They must be connected.
The black plastic box makes it nice to see what would go where.
ok I wired in all the pots. I have used the same wires to help with identification for those pots. Red for wire 1, white for wire 2, and black for wire 3.
What I get now is “sorta” of a sound.
The bypass’ed signal sounds find. When I engage the switch it sounds like a muffled distortion sound but there is an audible “wobble” to it and the sound only lasts for 3- 5 seconds and then fades out and I have to strum the strings to get any sound again.
Here are 2 new photos of the pots wired in within the 3d printed box.
Thanks Billy. I was VERY careful in populating the board, and I am no stranger to a soldering iron. I am really trying to learn about the electronics part. The schematic, what the components actually do in the circuit. Things I never learned when I was younger. I have wired tons of guitars over the years, but this is a whole different kind of world.
You need to go and re-bias all the transistors now starting with Q1 and work down the line. Make sure that you are using the correct trimmer for the transistor. Report your voltages.
Q1 = 4.97
Q2 = 5.03
Q3 = 5.02
Q4 = 5.04
Q5 = 9.06How do you adjust Q5? Build docs say get it as close to 5v as possible. I was able to do that with all the positions except Q5.
Looks like Q5 doesn’t need biasing it’s gate voltage should be the same as Q4s drain voltage the 2 pins highlighted in red below
I just checked and the voltage number is the same on Q4 Drain and Q5 Collector.
Your audio test should have greatly improved after biasing, what are the results?
Make sure all potentiometers are at about half way point.
Basically the same result. When I strike a note the sound is “distorted” like the pcb is kinda working, but the sound is VERY scratchy and fades quickly.
If I engage the switch to go back to bypass the clean sounds normal and fine.
- You must be logged in to reply to this topic.