Incorrect voltages after installing Speedball [resolved]
- Thread starter Adelz
- Start date
Adelz
New member
I removed the Speedball upgrade and it seems that the amp is working, so it appears that the problem is not the power supply. What are the most common mistakes to look for on the PCBs? Also, is it possible to install each of the PCBs one by one in order to see where the problem is?
You can put just the small boards in, then run the amp with the 3K resistors in place (and the 22.1K resistors removed).
-PB
-PB
Is this noise that you get in both channels?
Can you try connecting a source and listening to the amp? With unshorted inputs, you may end up getting some noise.
-PB
-PB
Adelz
New member
When plugged into my source I can hear music over the buzzing. The music is not distorted at all and the buzzing now appears to be softer in the left channel in comparison to the right. Right now I have the 3K resistors in place of the large PCB and the two small PCBs in the amp.
Adelz
New member
After a day of troubleshooting the problem is still exactly the same.
It's definitely not the power supply or anything that's in the stock Crack, as that works fine. It seems that the buzzing is being caused by the small PCBs but after resoldering every joint on them the problem remains. What should I do next?
Edit: With the large PCB and the 22.1K resistors between the red wires meant for the small PCBs, the amp functions perfectly, so I'm assuming that the connections of the red wires to the terminal strip are fine. All four resistors on the small PCBs measure correctly, even when measured from their solder joints on the boards. All four LEDs glow brightly and are in the correct orientation. At this point I'm assuming the problem is either one of the MJE350 transistors or a 2N2907. What is the most accurate way to test them?
It's definitely not the power supply or anything that's in the stock Crack, as that works fine. It seems that the buzzing is being caused by the small PCBs but after resoldering every joint on them the problem remains. What should I do next?
Edit: With the large PCB and the 22.1K resistors between the red wires meant for the small PCBs, the amp functions perfectly, so I'm assuming that the connections of the red wires to the terminal strip are fine. All four resistors on the small PCBs measure correctly, even when measured from their solder joints on the boards. All four LEDs glow brightly and are in the correct orientation. At this point I'm assuming the problem is either one of the MJE350 transistors or a 2N2907. What is the most accurate way to test them?
If you believe the transistors are the problem, then they should be replaced. It's possible that one set of transistors was damaged from the R1 swap, but not both sets.
-PB
-PB
Yes.
-PB
-PB
Yes.
-PB
-PB
Yes, I think you have an issue elsewhere. I still believe that you have an iffy connection in your amplifier, and the Speedball constant current sources are simply more sensitive to the issue than the stock circuit.Adelz said:
There could also be an environmental problem close to the Crack (computer, wifi router, etc.) that could be causing some interference. It might not hurt to try the amp in another room.
-PB
Adelz
New member
I've once again resoldered pretty much everything. Where should I go from here? I really don't want to just continuously resolder every joint; I feel like after all of this it is almost definitely a problem with one of the components. Could the transformer itself be causing the buzzing?
