Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: Souter on August 24, 2019, 08:07:52 AM

Title: First Time Builder - Static and distortion! [resolved]
Post by: Souter on August 24, 2019, 08:07:52 AM

Hi,

I've just completed my crack and all checks checked out as okay.

I then turned the amp on for a while and the tubes glowed and everything was looking good. I was getting very excited to hear how it sounds!

I then pluged my phono cable into the crack and went to place the other end into my headphones (Fostex t50rps).
A big spark shot out from the cable to the headphone!

I then decided to use one of the kids headphones for further testing!!!

I plugged a pair in and then listened, the audio was very distorted. As I pulled the phono cable out of the Crack a huge pop came out from the headphones and a spark emitted from the phono jack.

Is there anybody out there who could give any advice on this? I'm a bit gutted!

Cheers,
john.

Title: Re: First Time Builder - Static and distortion!
Post by: Paul Birkeland on August 24, 2019, 08:39:10 AM

Can you post your voltages and some build photos?

Title: Re: First Time Builder - Static and distortion!
Post by: Souter on August 24, 2019, 09:56:11 AM

No Problem! Thanks for your reply.

Terminal       Voltage
01                83.1
02                178.3
03                0
04                178
05                85.6
06                0
07                108.8
08                0
09                111.6
10                0

Terminal      Resistance
01                *
02                *
03                0
04                *
05                *
06                0
07                2.96
08                0
09                2.96
10                0
12                0
13                *
14                0
20                0
22                0
B3                2.96
B6                2.96

RCA Jacks
Center Pin     Black-90.5 / Red-91.9
Ground tab    00.2

I've also attached some pictures. Hope they are clear enough.

Title: Re: First Time Builder - Static and distortion!
Post by: Souter on August 24, 2019, 10:05:12 AM

More Pics

Title: Re: First Time Builder - Static and distortion!
Post by: Souter on August 24, 2019, 10:09:12 AM

More pics!

Title: Re: First Time Builder - Static and distortion!
Post by: Souter on August 24, 2019, 10:19:40 AM

And another...

Title: Re: First Time Builder - Static and distortion!
Post by: Paul Birkeland on August 24, 2019, 10:49:00 AM

A5 looks to not be soldered.

The junction of the black wires on the headphone jack does not look to be well soldered (and would definitely cause the problem you observed).

10L needs more solder (and heat).

The #8 nuts need to be installed so the power transformer doesn't fall out.

Title: Re: First Time Builder - Static and distortion!
Post by: Souter on August 24, 2019, 11:27:58 AM

Thanks paul, very much appreciated.

I'll take a look at your points in the morning.
Can't believe i forgot to put the nuts in!!
Will not be easy to do now though.

Title: Re: First Time Builder - Static and distortion!
Post by: Souter on August 25, 2019, 04:35:42 AM

Paul, you are a total genius.

My creation has come to life.
No sparks flying and no distortion!

Thanks so much!

Title: Re: First Time Builder - Static and distortion!
Post by: Paul Birkeland on August 25, 2019, 09:27:37 AM

Good to hear!