• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Class D Amp Cutting out on stage, Not at home when testing

#21
agedhorse said:
Without troubleshooting, how do you know this is the OP's case? It may be, but just as likely not IME.
Click to expand...
I've seen it with 3 different brands, including my PF-350 which has more power. I hit the strings pretty hard so it's more likely to happen to guys like me than others. In all three cases, it was the protection circuitry kicking in to protect the amp. I agree it might not be the case with the OP.
 
#22
Happy Face said:
Interesting point the Ancient Steed mentioned about tweeters.
Click to expand...
Applies to some class D amps but only with crossovers that contain specific design defects. Other class d amps won't protect themselves but simply fail.
 
  • Like
Reactions: basscapes
#23
jeff7bass said:
I've seen it with 3 different brands, including my PF-350 which has more power. I hit the strings pretty hard so it's more likely to happen to guys like me than others. In all three cases, it was the protection circuitry kicking in to protect the amp. I agree it might not be the case with the OP.
Click to expand...
Here's the problem with a small sample size, the amps that you may have experience with may be amps that tend to exhibit this behavior (class D or not). The amps that I have experience with absolutely do not exhibit this behavior unless there is something else going on. I would include the GK MB series in the list of no problem with this.
 
  • Like
Reactions: jeff7bass
#25
agedhorse said:
Here's the problem with a small sample size, the amps that you may have experience with may be amps that tend to exhibit this behavior (class D or not). The amps that I have experience with absolutely do not exhibit this behavior unless there is something else going on. I would include the GK MB series in the list of no problem with this.
Click to expand...
The first time I saw this was a GK. My friend was playing thru the class D combo and had no problems. He let my other friend play through it for two songs and it was cutting out like crazy. My other friend is a rocker who rips into the strings. Great old-school rock player. That's the point. It's also the point that problems are more likely to occur in a band setting because that's when the amp gets pushed.
 
#27
If it happens only at a venue, this sounds like a circuit that is loaded to the edge of having the breaker blow. What you might be experiencing is the breaker almost halfway tripping. Some gear can sort of tolerate this, but some is very sensitive and will cut out. Next time I would just bring an extension cord, pick a different outlet to plug into, and hope it's on a different circuit. Try the one the guitarist is plugged into.

This happened once with my X32 digital mixer. The PA amps played on, but the mixer would drop its main fader to zero when it detected the power hiccup. Not fun. Moving to another circuit fixed it.
 
#28
…. which MB200, the early version with the green combo jack or the later Speakon only? … what else is plugged into the same circuit as your bass gear at your gigs? … when you are experiencing this, have you removed everything else in YOUR signal chain to go direct (bass to amp) to try and isolate the issue? … also, are you using passive or active setting on the amp and with what bass?
 
#29
sawzalot said:
If it happens only at a venue, this sounds like a circuit that is loaded to the edge of having the breaker blow. What you might be experiencing is the breaker almost halfway tripping. Some gear can sort of tolerate this, but some is very sensitive and will cut out. Next time I would just bring an extension cord, pick a different outlet to plug into, and hope it's on a different circuit. Try the one the guitarist is plugged into.

This happened once with my X32 digital mixer. The PA amps played on, but the mixer would drop its main fader to zero when it detected the power hiccup. Not fun. Moving to another circuit fixed it.
Click to expand...
Fortunately breakers don't half-way trip or they would only provide half-way protection.

Voltage drop is a different thing entirely, and it's possible that what the OP is experiencing is due to this. As a note, this can occur to non-class D amps as well, some amps (including a couple of my lead sled designs) do include low AC voltage protection so that the amp is protected when the voltage gets dangerously low. In many class D amps, this protection is present because some bad things can happen when the supply voltage falls, different from a traditional linear amp.
 
  • Like
Reactions: Loring and mbelue
#31
78C4841E-B483-4664-9961-933DD1DE4A40.jpeg That’s a good little amp, maybe it’s not gelling with that cab, I used this on my last gig with a 5 piece and loud guitarist and it performed great...
 
#39
Bar wiring always went, street to neon sign, to cash register, to bar fridge, to hot plate, to dishwasher, to the video game, to the stripper stage, to the bandstand.
That's the way I remember them running power to the band.
 
  • Like
Reactions: Loring

Latest posts

Top Bottom
Back