Speedball Upgrade Troubleshooting [solved]

[vicinus2202]

Hi fellow Bottlehead enthusiasts,

after being really amazed by the quality of the Crack itself (in combination with my HD650s) I could not resist upgrading it with the speedball upgrade, because I heard that it really significantly improves the Crack. I have finished soldering, but my Voltages are wrong on 2 terminals. Terminal 1 and terminal 6 are 0V and nothing I do seems to change that (I resoldered them twice so far). Also (probably part of that problem) the LEDs on the 9pin socket don't glow anymore. My last question: Do both of the Diodes on the small boards have to light up? Because right now only the right one of each board does so.

Thank you very much for every hint or idea, that gets me closer to the finished Crack!

[Paul Birkeland]

This problem is most often remedied by reheating the center leg of each MJE-350 thoroughly. 

It's also worth checking that the 2N2907's are in the small boards and the 2N2222's are in the large boards.

-PB

[vicinus2202]

Thanks for your help! Unfortunately reheating of the MJE-350 middle legs did not solve the problem and I checked the  2N2907's and the 2N2222's and they are all placed correctly. Do all LEDs have to light up (on all three boards and the 9 Pin socket)?

[Paul Birkeland]

I'm also guessing that you meant that terminal 1 and terminal 5 are 0? (Terminal 6 is supposed to be 0)

Does the 12AU7 still glow when you turn the amp on?

In which direction is the writing facing on the MJE-350's relative to the board?

-PB

[vicinus2202]

Sorry, of course I meant, that terminal 5 is 0. The 12AU7 still glows, yes. The writing on the MJE-350's is facing towards the right side (volume control).

[Paul Birkeland]

The writing on the MJE-350's is facing towards the right side (volume control).

There's your problem.

-PB

[vicinus2202]

Thank you so much, what a dumb mistake. Everything's glowing now, I almost feel like standing in front of a christmas tree

However there is now a different problem to be solved, because the voltage on terminal 5 is now at 150V (as well as on terminal 9). But I think thanks to your help I am almost there (y)

[vicinus2202]

Ok, I solved the last issue myself, I created a solder bridge rearranging the MJ350's.
Now all voltages are correct an I am ready for a test run.

Thank you very much again, PB, for your fast and precise help!!





It works and sounds incredible!!!!