Hello everyone, im new here but i couldnt resist, as ive had nothing but blowing fuses since ive owned my RB991 ( same as the 1080 apart from the remote trigger)
So far :my amp was originally driving 4 ohm sub in an enclosed space, fuses would blow on a regular basis, Lots of blame went into the speakers, position and aplication.
Now the amp is driving an 8ohm load, "driving me fullrange speakers", with the lid off, the amp has had three modifications, from rotel uk.
Burst of osc on power up:this was rectified by moving the protection power supply lead.
Whistle noise : this is the addition of a cap on the protection bored.
Ground shifting : my crossover being from car audio has floating grounds so the ground in the amp needed to be changed, this was the shorting of resistors on the input to the amp.
Guess what! the amp is well with in spec, there is no audible problems, it Can drive a 2 ohm load with no fuses blowing for some time, yet while its sitting on idle for a few hours, Sometimes !! it will blow the fuses, this is with the lid open and an 8 ohm load.
I think as this amp has stability problem ( because of the mod's with the oscalation), i recon a little mains spike can cause the amp to to self oscalate at high frequencies and thats when the fuses go.
Mains filters for everyone !!!
by the way i have 2 981's and 2 850's never had a problem it's just they sound like a bag of shite compared to the 991, always the way.. :-)
So far :my amp was originally driving 4 ohm sub in an enclosed space, fuses would blow on a regular basis, Lots of blame went into the speakers, position and aplication.
Now the amp is driving an 8ohm load, "driving me fullrange speakers", with the lid off, the amp has had three modifications, from rotel uk.
Burst of osc on power up:this was rectified by moving the protection power supply lead.
Whistle noise : this is the addition of a cap on the protection bored.
Ground shifting : my crossover being from car audio has floating grounds so the ground in the amp needed to be changed, this was the shorting of resistors on the input to the amp.
Guess what! the amp is well with in spec, there is no audible problems, it Can drive a 2 ohm load with no fuses blowing for some time, yet while its sitting on idle for a few hours, Sometimes !! it will blow the fuses, this is with the lid open and an 8 ohm load.
I think as this amp has stability problem ( because of the mod's with the oscalation), i recon a little mains spike can cause the amp to to self oscalate at high frequencies and thats when the fuses go.
Mains filters for everyone !!!
by the way i have 2 981's and 2 850's never had a problem it's just they sound like a bag of shite compared to the 991, always the way.. :-)
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