Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: clearumbrella on March 25, 2021, 11:00:02 AM

Title: Help with High Voltage Check [resolved]
Post by: clearumbrella on March 25, 2021, 11:00:02 AM

Hey all,
I finished assembling the Crack and it passed the resistance check but it failed the voltage check. Additionally, the LED from the center pin to A8 of the 9 pin socket does not light. I went ahead and reflowed the connections, but my voltage check on T1 and T7 remain too high.

Can anyone assist?

Here are my voltage results

T1      153v
T2      171.3v
T3      0v
T4      171.3v
T5      82.5v
T6      0v
T7      153v
T8      0v
T9      103.1v
T10    0v

Thank you!

Title: Re: Help with High Voltage Check
Post by: Paul Birkeland on March 25, 2021, 11:23:41 AM

Do both halves of the 12AU7 light up?

Title: Re: Help with High Voltage Check
Post by: clearumbrella on March 25, 2021, 02:06:49 PM

Yes, I believe so. Here's a picture of the tube.

Thank you for your help.

Title: Re: Help with High Voltage Check
Post by: Paul Birkeland on March 25, 2021, 05:47:05 PM

Can you post some photos of the 9 pin socket build area?

What DC voltages do you get at A3 and A8?

Title: Re: Help with High Voltage Check
Post by: clearumbrella on March 26, 2021, 04:38:47 AM

I believe I have fixed it. I checked the wire from T1 to A6 and noticed I stripped it poorly. I ran a new cable between T1 and A6 the voltages are reading more normal. T1 and T7 are fixed but now T2 and T4 are 179v instead of 170v. Since that's within that 10% tolerance, should I be good to go? Resistance check passed.

Thank you!

Last Voltage Check:

T1      81v
T2      179v
T3      0
T4      179v
T5      85v

T6      0v
T7      105v
T8      0
T9      107v
T10    0

Title: Re: Help with High Voltage Check
Post by: Paul Birkeland on March 26, 2021, 05:03:41 AM

Yes, that is well within the 10% tolerance.

Title: Re: Help with High Voltage Check
Post by: clearumbrella on March 26, 2021, 05:04:43 AM

Thanks for your help Paul.