Solved! Crack - First build - resistances incorrect [resolved]

[IanC]

Hi everybody!

First time builder here from The Netherlands (small country in Europe It has been a lot of fun so far building the Botlehead Crack. I really enjoy this project, this is my first vacuum tube amp project. I'll pair the crack with the Beyerdynamic T-90. When finished, I'll see if someone I know has an HD 650 to see what that sounds like.

I have been building the stock Crack so far, and when I came to measuring the resistance, I noticed some measurements are off.

I measured between terminal 12 and respectively:

-terminal 3:    1.6 Ohms
-terminal 8:    1.4 Ohms
-Terminal 13:  30 M Ohms (far off)
-Terminal 20:  0.1 Ohms
-Terminal 22:  1.4 Ohms


Has anybody got a quick answer to my strange measurements? Do I have a ground issue here, or might there be a capacitor problem (the one on terminal 12 and 13?)

Thanks in advance for your help!

Greetings, Ian.

[fullheadofnothing]

Terminal 13 is nothing to worry about. How various meters display that terminal will vary. The main issue is to make sure that it is not zero/very low.

The other terminals you ask about do point to issues with your grounding. Terminal 20 is probably fine, as it is well below 1Ω. My guess is there is a missing wire or poorly soldered connection on your ground buss somewhere - terminal 3, the potentiometer and the headphone jack are the main places to look.

[IanC]

Thanks Joshua! It was a wrong connection :S

I made a mistake in the wiring on the pot meter (ground, just like you thought)

Problem solved, all measurements correct. I'm listening to music now, my first vacuum tube experience... Nice!