Speedball: LEDs on first board not lighting; voltage tests are within spec

agitprop · 9553

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Offline agitprop

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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!



Offline Larpy

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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.

Larry


Offline agitprop

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Thank you!  Photos follow.



Offline Thermioniclife

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Q1a is mounted backwards, thats one problem.

Lee R.


Offline agitprop

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



Offline Thermioniclife

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I stand corrected sir.

Lee R.


Offline agitprop

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



Offline Doc B.

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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.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline agitprop

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Thank you!



Online Paul Birkeland

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  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?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man