The Audio Circuit

This issue only affects the Hummer. So if you have any other DTV, this doesn't apply to you.

If you have noticed that one of the SID voices seems louder than the other 2, you weren't imaging it. There is a defect on the board. If you want to verify your unit has this defect (It probably does) you can use their built-in test program to check for it. Hold down the A button when you power the unit on. When you get the spinning trucks, hit the B button. Now you are in a diagnostic program. You will hear a high pitched tone. If you move the steering wheel all the way to the left and right you will get two other tones at different pitches. Each of these three tones represents one voice on the audio circuit. If you have the defect, the center voice will be louder than the other two.

The good news is, you can fix it. There is a resistor that needs to be desoldered from the board. Then use some desoldering braid and remove the excess solder. You will notice that there is a trace on the board that runs from one side of the resistor to the other. Effectivly, removing the resistor from the circuit. In fact, if you turned your DTV on and played some music at this point it would sound no different than it used to. This trace needs to be cut. You will need to use a knife or other object to carefully scrape it away. You will want to check both solder-pads with a multi-meter to make sure you have cut it because sometimes it can look like it is cut, but isn't. Once it is cut, resolder the resistor back into place. Your audio will sound good now!

This is the audio-circuit of the Hummer unit. I have shown which resistor needs to be removed to correct the audio.

Llisten to two samples. This is the theme music to the game. I have both before and after versions.. What is interesting about this particular song is that the defective voice is the voice that plays the drums. So it actually doesn't hurt this particular music, in fact, actually seems to help it. However, other C64 music and sound effects are really poorly effected by the flaw, and sound much better with the fix.
audio_fixed.mp3 (682K)
audio_original.mp3 (742K)

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