Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: tommytak on February 25, 2018, 06:18:21 AM

Title: Unusual Voltage Readings [resolved]
Post by: tommytak on February 25, 2018, 06:18:21 AM

Hello I just finished installing the Crack and it passed all the resistance checks and both tubes light up but I keep getting unusual voltage readings and both the LEDs don’t seem to light up.

Here are my voltage readings
1. -0.871V
2. -0.870V
3. 0V
4. -0.87V
5. -0.869V
6. 0V
7. 4.9 mV
8. 0V
9. 3.9mV
10. 0V

Thank you in advance for all your help!

Title: Re: Unusual Voltage Readings
Post by: Paul Birkeland on February 25, 2018, 06:28:29 AM

What voltage do you get at terminal 13?  Can you post photos of your build?

Title: Re: Unusual Voltage Readings
Post by: tommytak on February 25, 2018, 06:49:41 AM

Here's a picture of my build.

After I read your comment, I noticed that the 270 Ohm 5W resistor wasn't soldered in with the rest so I just resoldered terminal 13U with the resistor end connected. I will redo my resistance and voltage readings right now and give you the numbers again.

Also just to clarify, when we do the checks, "the ground buss at terminal 12U means I clip the black lead then clip the red lead to the other terminals for checking right? Sorry this is my first time building anything related to electronics haha

Title: Re: Unusual Voltage Readings
Post by: tommytak on February 25, 2018, 07:10:23 AM

So after I resoldered it, the resistance checks out and both LEDs are now lit!
Here’s my new voltage reading!

1. 76.8V
2. 174.1V
3. 1.1 mV
4. 174.1V
5. 78.4V
6. 1.1mV
7. 104.8V
8. 1.4mV
9. 105.4V
10. 1.2mV

Now the only thing off is that the terminals that should have 0V have mV readings on them

Title: Re: Unusual Voltage Readings
Post by: Paul Birkeland on February 25, 2018, 08:12:57 AM

1.1mV is 0.0011V, which is close enough to 0.

Title: Re: Unusual Voltage Readings
Post by: tommytak on February 25, 2018, 08:25:20 AM

Hi Paul,

the amp works perfectly now! Thank you for your assistance