Hifonics BRX5016.5 sub output 5 channel

mikep28

Member
2015-02-20 5:28 am
Just finished a custom install in a 2011 mustang. About hour into the test tune and play session all sound ceases. Wasn't really slamming on it amp was hardly hot. Driving 4 ohm 1-4 channel and 2 RE AUDIO 10's 4 ohm in parallel (2 ohm). Well unplug wire for 5th channel disconnect remote on. Yep 31 VDC for brief second. So I know I got amplifier output problem. Anyone have one apart yet? What it use for outputs in the class D section. Kinda like to know so I don't disassemble if I don't have the parts. Thanks
 

mikep28

Member
2015-02-20 5:28 am
Looks like IRFP250N ... Damn I dont have that in stock... anything else work in the place? IRFP3415? I have IRFP240N ---- work?

difference is 240N is 20Amp and IRFP250N is 30amp ... This amp was a victim of manufacturing defect stress fracture through 2 leads on one of the originals, took out 1 of the others and threw amp into protect....
 

mikep28

Member
2015-02-20 5:28 am
Ok got the order in from future electronics this morning. Installed the output transistors. Left it on the bench for about 30 minutes. Sounded fine then ran a 60 HZ sinewave into the amp. Looks good on the scope. All looks good but this is the same as I checked when I installed the 240N's. Perry anything else I can do make sure this amp is in fact 100% ? I don't really need another embarrassment with this customer after the back ordered parts and defective out of box in one hour amplifier.
 

mikep28

Member
2015-02-20 5:28 am
My power supply is only 35 amp max. Musically I had it lot louder than the first time I had it on the bench. I also ran channel 1 and 2 bridged and channel 3 and 4 bridge into 4 ohms. The 5th sub channel 2 ohm.

On the scope with 50hz note I used four 2 ohm 100 watt resistors in a parallel series configuration to achieve 2 ohms. I got the amp quite warm.

I assume I could get the kinetic 2400 battery out for power and really take it up stairs.
 
When testing an amp, I generally use dummy loads with a load that is 2x the lowest rated load (2 ohm load for a 1 ohm amp). I drive the amp with a track from a bass disc so that it reaches clipping regularly. I typically run class AB or class B amps at least an hour (or until they thermal) and class D amps for about 3 hours. If they make it through that, there are rarely any problems. All amps should be rechecked to confirm that they're still working properly (quick check) after they've cooled to room temperature.

When testing, set the bass boost to the minimum position so that the amp will work harder (near clipping at all frequencies, not just at the frequency of the bass boost).
 

mikep28

Member
2015-02-20 5:28 am
I drove this amp to the limits of my power supply the clipping I saw on the scope was probably because of the limits of the supply. I drove the amp a little over an hour. Got it pretty warm. I then hooked it up to the large AGM battery drove it and the amp preformed very good. I reconnected the amplifier to a 4 channel load at 4 ohms to my shop test speakers and the 5 channel to a pair of 10's at a 2 ohm mono load with regular music source. It's been playing over an hour and still performing. I guess I can consider this one repaired. Time to contact my customer.

So my final assumptions were the transistor with the stress fractures on the lead was the cause of failure in the amplifier. You see many like that? Just failed. No smoke. No fire. No boom. Amplifier protect in this amplifier actually works great.