Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: Applemacman on October 20, 2020, 04:54:29 AM

Title: Bottlehead crack speed ball issue [resolved]
Post by: Applemacman on October 20, 2020, 04:54:29 AM

Hi, just installed the first board of the speed ball for the bottlehead crack. One of the four leds is not lightening up. Below are the voltages.

OA. - 51.75
IA. - 156.8
B. A/B - 0
IB. - 157.1
OB. - 72.9

Ive included a picture of the board too. The led not lightening up is the one just below the AB red wire.

Title: Re: Bottlehead crack speed ball issue
Post by: Applemacman on October 20, 2020, 04:57:44 AM

Picture of the boatd

Title: Re: Bottlehead crack speed ball issue
Post by: Paul Birkeland on October 20, 2020, 05:05:12 AM

I get a corruption error attempting to open your PDF.  Based on the voltages, I would say you have a PN2907 in backwards.

Title: Re: Bottlehead crack speed ball issue
Post by: Applemacman on October 20, 2020, 07:28:44 AM

You were right I did had to change it for a 2N2907. I believe this is ok to use. Im now getting voltages of:-
OA- 69.5
IA - 152.5
B A/B - 0
IB - 152.3
OB - 72.7

Which I believe is ok due to tube tolerances. Am I correct. Just want to make sure?

Title: Re: Bottlehead crack speed ball issue
Post by: Paul Birkeland on October 20, 2020, 08:04:52 AM

Why did you have to change it?  You can pop it out and flip it around...

The current voltages you have look fine to me.

Title: Re: Bottlehead crack speed ball issue
Post by: Applemacman on October 20, 2020, 11:01:14 PM

I tried to pop it out with my desoldering iron but i stupily bent the leads over and could not get it out. I have certainly learnt alot building this amplifier my first.

Thanks for the support and help.