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Bottlehead Kits => Crack => Topic started by: agitprop on May 19, 2024, 02:15:26 PM

Title: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: agitprop on May 19, 2024, 02:15:26 PM

Built Crack yesterday.  Tested and worked well.

Just installed first half of Speedball.  None of the four LEDs on the Speedball's small board light up; the two original LEDs on the Crack's 9-pin socket work fine.  I'd be shocked if I overheated the four small-board LEDs when soldering; they got a lot less heat than the 9-in socket LEDs. I am using a Hako digital iron at 650 and Cardas Quad Eutectic, and I have a good bit of soldering experience.

Got the following, ostensibly nominal test voltages:

Terminal     Voltages (DC)
OA                      80.8V
IA                     176.2V
B-A/B                      0V
IB                     176.5V
OB                      80.5V

I would love to include photos, but I can't figure out how to either directly include images or share imgur links in a post.  Please feel free to clue me in!

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: Larpy on May 20, 2024, 05:37:23 AM

When you post, click on "Attachments and other options" and then "Browse" and then add your photo.  Click on "more attachments" to add additional photos.

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: agitprop on May 20, 2024, 06:50:34 AM

Thank you!  Photos follow.

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: Thermioniclife on May 20, 2024, 07:41:24 AM

Q1a is mounted backwards, thats one problem.

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: agitprop on May 20, 2024, 08:38:55 AM

Hmmm.  Here is the cover photo of the Speedball manual, which shows the orientation of the transistors matching mine:

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: Thermioniclife on May 20, 2024, 08:41:43 AM

I stand corrected sir.

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: agitprop on May 20, 2024, 09:04:11 AM

Do these LEDs require the amp to be pushing audio to light up to a brightness where they can be seen in normal lighting?

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: Doc B. on May 20, 2024, 09:15:53 AM

Sounds like your amp has the right voltages so you should be good to go. The big board LEDs are about the same brightness as the 12AU7 socket LEDs. The small board LEDS are much dimmer because they pass less current. You may want to darken the room to observe them.

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: agitprop on May 20, 2024, 09:41:39 AM

Thank you!

Title: Re: Speedball: LEDs on first board not lighting; voltage tests are within spec
Post by: Paul Birkeland on May 21, 2024, 04:45:40 AM

Quote from: agitprop on May 19, 2024, 02:15:26 PM

  None of the four LEDs on the Speedball's small board light up

If you turn the lights off in your room, can you see them lighting up now?