Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: jj4001 on February 17, 2021, 02:09:15 PM

Title: New Crack - test results feedback please (solved)
Post by: jj4001 on February 17, 2021, 02:09:15 PM

Just finished my Crack build today. Here are my test measurement results. Please let me know if you see anything that looks out of place. Thank You!!

1  *
2  *
3  0.1 ohm
4  *
5  *
6  0.1 ohm
7  2.9 K ohms
8  0.1 ohms
9  2.9 K ohms
10  0.1 ohm
12  0.1 ohms
13  *
14  2.4 M ohms
20  7.8 M ohms
22  0.1 ohms
RCA center and ground measured correct


Thank you!!

Title: Re: New Crack - test results feedback please
Post by: OneyedK on February 18, 2021, 02:28:17 AM

Measurement 12 is ok
So my guess is that you forgot to connect 12 - 14 -20
(top of page 40 and top of page 41)

Title: Re: New Crack - test results feedback please
Post by: Paul Birkeland on February 18, 2021, 06:20:42 AM

Post some build photos around the 6 lug strips.  You are either missing a wire or one is poorly soldered up there.

Title: Re: New Crack - test results feedback please (solved)
Post by: jj4001 on February 19, 2021, 07:28:20 PM

Thanks everyone. I re-flowed the 6-lug strip joints and the headphone jack and that fixed the main issue. There was some very faint left channel frying bacon crackling sound and RF pickup I was able to notice after that. I decided to just re-flow all the remaining solder joints at that point (really didn't take very long) and now both channels are perfectly quiet, and the amp sounds great.

I do have one additional question - is there a fairly simple mod that reduces the gain somewhat? I'm getting a pretty small amount of volume pot turn to get my HD650's up to a comfortable volume. A little more useful volume knob turn would be nice.

Thanks again

Title: Re: New Crack - test results feedback please (solved)
Post by: OneyedK on February 20, 2021, 12:05:27 AM

;) pssst, the answer is in the Crack FAQ ;)
https://forum.bottlehead.com/index.php?topic=4295.0