Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: tdahlen on January 18, 2019, 11:42:25 AM

Title: Just built crack, two issues [resolved]
Post by: tdahlen on January 18, 2019, 11:42:25 AM

Hello,
  I just finished building my crack headphone kit but noticed two issues so far:

1)  Voltage measured on terminal 9 was higher than expected.  The guide indicates 90 - 115 V are expected, but I am measuring 165V.  All other terminals measured okay.

2)  The left channel doesn't seem to be working.  If I pull the headphone jack out slightly I got sound from both channels, but this doesn't seem right.

Any idea are appreciated, thanks.

Title: Re: Just built crack, two issues
Post by: Paul Birkeland on January 18, 2019, 03:56:44 PM

It's really important that you not use any of our products that don't pass the voltage and resistance checks.  An amp that hasn't passed its voltage and resistance checks can be dangerous to use, especially when you're plugging things into it that are wrapped around your head.

What resistance measurement did you get at terminal 9?

Title: Re: Just built crack, two issues
Post by: tdahlen on January 19, 2019, 04:59:32 AM

I unplugged the tubes and remeasured resistance at all of the terminals.   Terminal 9 was 2.9 K ohms.  All of the others matched the instructions as well.

Title: Re: Just built crack, two issues
Post by: Paul Birkeland on January 19, 2019, 05:36:51 AM

I'd be interested in seeing some photos of your build, and also of knowing your voltages at terminals 1 and 5.

-PB

Title: Re: Just built crack, two issues
Post by: tdahlen on January 19, 2019, 06:18:23 AM

Here are my measurements and a few pictures.  Let me know if you need a better look at an area.

1. 81.2 V
2. 164.2 V
3. 0 V
4. 164.5 V
5. 80.9 V
6. 0 V
7. 103.5 V
8. 0 V
9. 164.8 V
10. 0 V

Title: Re: Just built crack, two issues
Post by: Paul Birkeland on January 19, 2019, 06:20:03 AM

You have a wiring error at B5/B6.

Title: Re: Just built crack, two issues
Post by: tdahlen on January 19, 2019, 07:09:11 AM

Yep, that was it.  I corrected the wiring at B5 and now the voltages are measuring correctly.  Thanks for your help.