High voltage on terminal 1

[Paul Birkeland]

You haven't mentioned this until now, was it a problem when you first posted?

[pdrm360]

Honestly, I didn't check the LEDs on the large board at the beginning.

[pdrm360]

It sounds great even without Speedball.

[pdrm360]

Update: I found a same issues with 2N2907 transistor on the A board. 

Is it possible that the Speedball's issues are related to the TIP-50 and 2N2907 transistors?

[Grainger49]

The best way to check a solder joint is not to touch it.  If you are checking the final lead on the transistor that feeds the output of the C⁴S board check from the transistor lead to the terminal that the wire from the board ends up on.  This checks the transistor solder joint, the trace on the board, the solder joint on the output point of the board and the wire to the terminal in the amp.

The point is that if you check resistance on a bad solder joint you may be forcing it to read good when it is actually bad.

[Paul Birkeland]

It is highly unlikely to have a shorted transistor unless there was some mode of damage to begin with.  Some examples are:

Solder bridging pins on the transistor
Shorting the transistor while trying to measure voltages on its pins
Installing an incorrect transistor on the PCB


I would suggest running the amp without the 6080 and examining the voltages on terminals 1 and 5.  Do they run stably?

[pdrm360]

It is highly unlikely to have a shorted transistor unless there was some mode of damage to begin with.  Some examples are:

Solder bridging pins on the transistor
Shorting the transistor while trying to measure voltages on its pins
Installing an incorrect transistor on the PCB


I would suggest running the amp without the 6080 and examining the voltages on terminals 1 and 5.  Do they run stably?

I'm not sure what happened, but I have two shorted transistor. The Speedball’s boards weren’t connected to the Crack when I check the transistors.

I don’t know if it’s something on the Speedball’s boards that cause this issue or they had the shorted pins since beginning.

The Crack is working fine after I removed the Speedball, and all the voltages are correct.

[pdrm360]

The best way to check a solder joint is not to touch it.  If you are checking the final lead on the transistor that feeds the output of the C⁴S board check from the transistor lead to the terminal that the wire from the board ends up on.  This checks the transistor solder joint, the trace on the board, the solder joint on the output point of the board and the wire to the terminal in the amp.

The point is that if you check resistance on a bad solder joint you may be forcing it to read good when it is actually bad.

I did this (the trace on the board), but I've not found any loose connection.

[pdrm360]

Is it any recommended place for buying replacement parts?

[Paul Birkeland]

I would suggest running the amp without the 6080 and examining the voltages on terminals 1 and 5.  Do they run stably?

[pdrm360]

Will do this.

[pdrm360]

I would suggest running the amp without the 6080 and examining the voltages on terminals 1 and 5.  Do they run stably?

With Speedbal?  without the Speedball they run stably. 

[Paul Birkeland]

With the Speedball.