Speedball Upgrade problem & Gears setup question

[hnguyen]

Good evening all,

I am building my Bottlehead Crack for the first time. The Crack worked well, all the Voltage and Resistance numbers were correct. So I decided to do the Speedball Upgrade. Every numbers were right except Terminal 9 and Terminal 10.

T9 was 176V while it should be 100V
T10 was 0.6-0.8V while it should 0

I checked my Crack many times and couldn't find a problem except at B+, looked like the 3 pads touch each other during soldering (https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fdiy.koenigs.dk%2Fwp-content%2Fuploads%2F%2F2014%2F02%2Fdc794c3d6a1515e6822d6e5180b3c5b09b942176.jpg&hash=8b77310c3da0419ad27b42c9e9a67bdbd7b5954c).

However, when I put my headphone in to test the sounds, everything worked fine. I could hear very clear sounds both ears. So is it normal or it is just my imagination that it works fine?

And I have one more question, my setup is like this:

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FvGRaijL.jpg&hash=eb5c73d984537790617a70883bcc4c85883f20b1)

Crack --> O2 ODAC --> Laptop. I just don't know whether the ODAC part works. Like I turned the ODAC power off, or turned the volume up and down, nothing changed. So is it the right setup or the ODAC is unnecessary?

Thanks very much for your time.

[mcandmar]

The ODAC is a small board inside the O2 amplifier case.  The ODAC itself is USB powered so with the main O2 amp turned off it will still function and provide an output via the input socket as you have it connected.

The volume control will do nothing as its part of the main O2 amp.  Best practice is to leave the volume on the computer up fully and control it via the Crack.

[Grainger49]

In answer to your question about the 3 B+ pads, they are intended to be shorted together.  Electrically they are the same point.

[hnguyen]

Thanks for you guys' answers. So about the T9 & T10 Voltage, is something wrong with it? It is higher than expectations but the sound is still good. Thanks.

[Paul Birkeland]

If sound was coming out both channels, then your voltage checks are incorrect.  Can you let the amp warm up for 30 seconds or so, then retest? 

176V is not correct, and could be an issue with the soldering on the center leg on the TIP50C feeding that terminal.

-PB

[fullheadofnothing]

The picture of the amp on the desk appears to show a partially inserted headphone plug. If the amp was listened to in that state, there would be sound from both drivers, but there would only need to be one channel functioning.

[Doc B.]

Ooh, nice catch. It probably is only working on one side.

[Natural Sound]

The picture of the amp on the desk appears to show a partially inserted headphone plug. If the amp was listened to in that state, there would be sound from both drivers, but there would only need to be one channel functioning.

Along those lines, the 6080 doesn't appear to be pushed all the way down either.

[hnguyen]

Oh too bad you guys are right. When I fully inserted my headphone plug, just the right channel worked. So I guess I will have lots of work to do to fix this. Do you have any idea why this happens? Thanks very much.

[fullheadofnothing]

[...] Do you have any idea why this happens? Thanks very much.

[...] 176V is not correct, and could be an issue with the soldering on the center leg on the TIP50C feeding that terminal.

[hnguyen]

Things went totally badly for me. I am worried right now. So I went from everything works nearly fine except the T9 high voltage and just one channel to:
- Only two LEDs on the PC board work. The other 2 LEDs on PC board and 2 LEDs on octal socket (A) don't lit.
- When I turn the power on to measure Voltage, there are smoke from the Xicon P 5W 270 and the two resistances it bridges together. (http://i.imgur.com/a2urozv.jpg)

Here are the pictures of my PC board:
- Is it because my terrible soldering: http://i.imgur.com/AWVe3HU.jpg
- http://i.imgur.com/TaPDVY9.jpg
- The LEDs down left side work. The up right side don't: http://i.imgur.com/Um1MmQQ.jpg

Please help me with this. Thanks very much

 

[hnguyen]

So after re-soldering lots of things. All the LEDs lit now. However the Terminal 9 is still 180V and Terminal 10 is now 48V. What did I miss here, would anybody please tell me?...

[Paul Birkeland]

You spotted the error.

On the bottom of the big PC board, there are 3 pins on the TIP50C.  You soldered all 3 pins together, which shorts out everything.

The transistor may or may not be destroyed in the process.

You should use much, much, much less solder when building these boards.

-PB

[hnguyen]

So I spent my weekend try to de-solder and solder my Crack's joints. The voltages I got after all were a little bit higher (although were still in the 10% - 15% range). However, one of the LED didn't lid no matter how I tried (I ordered many LEDs since they were cheap and already replaced like 2 or 3 but it didn't work, I guess it was not the LED itself) (https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FrNNf579.jpg&hash=af66ff75d59551c092804002e475e07f4d2e7ed7) (https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fzv4RYQu.jpg&hash=590e8c179f9cb143da4651e141eff379927b203b) Here are the voltage, in case it will help the troubleshoot Terminal Expected Result Terminal 1 75-90 73 Terminal 2 170 192 Terminal 3 0 0 Terminal 4 170 192 Terminal 5 75-90 78 Terminal 6 0 0 Terminal 7 100 108 Terminal 8 0 0 Terminal 9 100 113 Terminal 10 0 0 Terminal 11 0 0 Terminal 12 0 0 Terminal 13 170 193 Terminal 14 0 0 Terminal 15 185 207 Terminal 20 0 0 Terminal 21 206 221 Thanks for your time.

[Paul Birkeland]

I could imagine there being a funky joint on the underside of that big board that's responsible for that LED not being as bright.

Your voltages look good, how is the sound?

Yes, an LED not lighting is the LED itself maybe 1-5% of the time.

-PB