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Bottlehead Kits => Crack => Topic started by: mfryan on January 21, 2017, 01:45:13 PM

Title: Crack 1.1 Buzzing with Distortion in Left Channel [resolved]
Post by: mfryan on January 21, 2017, 01:45:13 PM
Hey everyone,

     I know this has come up before and seems like the consensus is that it's a grounding issue, but I have probed around and my grounding seems to be fine.  I'm uploading some pictures if someone can spot something I'm missing.  Any help is appreciated.  Thanks!

Cheers,
Matt
Title: Re: Crack 1.1 Buzzing with Distortion in Left Channel
Post by: mfryan on January 21, 2017, 01:52:06 PM
I should probably clarify... I just finished the Crack yesterday.  And I'm really excited and happy with it (except for this one issue obviously).

The buzzing is audible from the moment I turn the power on and seems to get a little louder as the tubes heat up and then planes off.  After about 15-20 minutes there's some noticeable distortion in the left channel (as in a sort "blown speaker" kind of sound)... actually I can also hear it in the Right channel too.

Thanks again!
Title: Re: Crack 1.1 Buzzing with Distortion in Left Channel
Post by: Doc B. on January 21, 2017, 02:31:35 PM
voltages might help
Title: Re: Crack 1.1 Buzzing with Distortion in Left Channel
Post by: mfryan on January 21, 2017, 07:45:54 PM
So, when finished assembling the kit yesterday... all the voltages checked out perfect.

Now here are voltage test results now:

1- OL (Rearmost LED goes dark.  I.e. LED closer to A7 and A8)
2- OL
3- 0 Ohms
4- OL
5- OL (Frontmost LED goes dark)

6- 0 Ohms
*7- OL Here's where it's tricky:  First I had OL.  Then I had 2.9... then I noticed the LEDs were off and that the tubes were cold.  I turned it on and I got OL again.  I turned the light switch that controls the outlet off, but still had it plugged into the wall and got 3.04.  I unplugged it altogether and get 2.95.
8- 0 Ohms
*9- Same as 7. 
10- 0 Ohms

12- 0 Ohms
13- OL
14- 0 Ohms

20- 0 Ohms
22- 0 Ohms

*B3- Same as 7.
*B6- Same as 7.

RCA
Center Red- 98.9
Center Black- 103.2
Ground tab- 0 Ohms



Don't quite know what to make of it...  thanks for the help!
Title: Re: Crack 1.1 Buzzing with Distortion in Left Channel
Post by: mfryan on January 21, 2017, 07:55:54 PM
Another note... the distortion is definitely only occurring on the right channel now.  But the buzz is on both and is independent of the volume.
Title: Re: Crack 1.1 Buzzing with Distortion in Left Channel
Post by: mfryan on January 21, 2017, 08:02:53 PM
I don't know if this is relevant, but I just removed the headphone plug from the headphone jack and it is pretty hot.  Is that normal?
Title: Re: Crack 1.1 Buzzing with Distortion in Left Channel
Post by: mfryan on January 21, 2017, 08:17:09 PM
*Ahem* Excuse my noobiness... I just realized I posted a bunch resistance checks instead of voltages...

Anyways, here are the voltages:

1- 79
2- 178/9 (alternates)
3- 0
4- 178/9
5- 79

6- 0
7- 103/4
8- 0
9- 102
10- 0

They all seem to be in the indicated range, right?
Title: Re: Crack 1.1 Buzzing with Distortion in Left Channel
Post by: Paul Birkeland on January 22, 2017, 09:36:49 AM
The juncture of the black wires on the headphone jack is not properly soldered (see in the photo how one wire is just floating in the middle of the terminal).
Title: Re: Crack 1.1 Buzzing with Distortion in Left Channel
Post by: mfryan on January 22, 2017, 11:46:28 AM
Thank you Caucasian Blackplate!!!  I look it over time and again and did not catch that...  That solved it.  Now it's quiet and the sound is incredibly good!  Thanks a million!