Visual inspection difference [resolved]

[Umustbekidn]

Howdy folks,

Finished assembly of my crack last night and noticed a couple differences during the visual inspection. See attached image; two connections circled at one end of the transformer are different (posts 17 & 14 vs. 18 & 15).

Perhaps this is just the wiring I used based on my home AC voltage, but I wanted to be sure.

Thank you kindly.

-update: After performing the resistance check, one item did not measure as indicated on page 47 - terminal 20 was not 0 ohms, instead it showed 50k ohms and increasing. See image attached for highlight.

Would all this be expected if I followed the wiring instructions for house voltage under 115vac (pg. 24)?

Thanks again!

 

[Paul Birkeland]

Perhaps this is just the wiring I used based on my home AC voltage, but I wanted to be sure.

You have your power transformer wired for an incoming voltage of less than 115V AC.

-update: After performing the resistance check, one item did not measure as indicated on page 47 - terminal 20 was not 0 ohms, instead it showed 50k ohms and increasing. See image attached for highlight.

Terminal 20 connects to terminal 14 with a piece of black wire.  Does terminal 14 measure 0 ohms to ground?  If yes, then the wire connecting terminals 20 and 14 is not adequately connected.

It is very important that you do not turn on your Crack before this issue is remedied.

 

[Umustbekidn]

Thank you for your reply!

Yes, I measure 0 ohms at terminal 14 to ground. Oops...

I shall work on that connection in the morning, and report back.

(I appreciate your word of caution. Thank you.)

 

[Umustbekidn]

Hi Paul,

Upon further inspection, I found the wire connecting terminals 14 and 20 to be completely loose at terminal 14... I could literally slide it in and out of the connection. Bingo.

I re-flowed the solder and added a bit more at terminal 14, which appears to have fixed the issue. I re-ran the full resistance check, and am copying the full results below for reference. Please let me know if this looks okay to proceed.

Terminal = Reading
1 = No Reading
2 = No Reading
3 = 0 ohms
4 = No Reading
5 = No Reading

6 = 0 ohms
7 = 2.9k ohms
8 = 0 ohms
9 = 2.9k ohms
10 = 0 ohms

12 = 0 ohms
13 = 2k ohms and increasing
14 = 0 ohms

20 = 0 ohms
22 = 0 ohms

B3 = 2.9k ohms
B6 = 2.9k ohms

RCA centers = 100k+ ohms
RCA grounds = 0 ohms

Again, thank you kindly for your assistance.

 

[Paul Birkeland]

Looks like it's time to power it up!

 

[Umustbekidn]

Here are the results of my voltage test:

Terminal = VDC
1 = 90v
2 = 200v
3 = 0v
4 = 200v
5 = 85v

6 = 0v
7 = 120v
8 = 0v
9 = 115v
10 = 0v

Both LEDs are on.
No smoke, no crackling sounds, no sparks.

As I write this I am listening to a song by Dream Theater titled "our new world".
I'm driving the amp with a Fiio V1, and listening on a pair of Beyerdynamic DT770s - 250 ohm model
Fiio output at max.
With the volume pot at 1/2, the listening level is very nice!
I can't crank it up to 3/4, as it gets uncomfortably loud there.
But this is absolutely wonderful.

I think I'll spend the rest of my new year's eve listening to my collection, and maybe even rolling a few tubes I have prepared just for this occasion...

Thank you kindly for your help!

 

[Doc B]

Well done!