VOX AD100VT Broken!! (Makes siren noise)

My VOX AD100VT has developed a siren noise. This video shows the amp and the noise it makes. In addition, turning the knobs has no significant effect on the sound produced. The Amp model knob does however, suggesting the fault lies before the model processor. The power knob on the back controls the overall volume of the siren noise.

When powered, the noise starts low frequency and gets high with a period of about three seconds. Upon power off the reverse is true, but only once.

Category:

Science & Technology

Tags:

• Broken
• VOX
• AD100VT
• amp
• siren
• noise

[kk9anathoth]

It looks like you don't have the original power cord. Is this true?

[DavidRWBarr]

@kk9anathoth that's a keen eye. No it is not the original cord, but it is one of several I use all the time. It just happened to be the one I used when taking the video. It started making the sound mid-rehearsal, implying something went pop.

[DavidRWBarr]

Well I replaced the tube, and the fault remained. After freezing several of the power components to see if it was a power/temperature issue, I concluded it must be a fault with the dsp board.

As the speaker cones are in excellent working order, and the amp does look cool, I modified it onto a cabinet for use with a head. I did this in such a way that if a solution is ever found, I can use the combo again.

[DavidRWBarr]

Power cycling does not fix the problem for me. I thought it was the tube, so I replaced it, but that made no difference. It takes about 10-15 minutes before it starts doing it.

Still investigating

[lucariow]

It makes that sound if the pre-tube is broken if im right.

[CzarThePlezer]

The amp seems a little gassy

[futureunknown]

Killer effects! lol ever find out what the problem was?

[M3ND3LA]

Sounds more like the VOX's farting at ya

[nhhshusky21]

Lol

[kk9anathoth]

I'm just grasping at straws here but. Do you have a manual?

[kk9anathoth]

I'm wondering if u put to munch or not enough power in to the amp and over time it has fried something. Because it's not the right cord. Maybe you could check your fuse if u haven't already.

[onnyang]

@BoBwilderness

LMAO