Been there, done that: HIP4080 is a piece of ****, when you look at it [monty python].
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I've started working back once again on this amplifier.
HIP4080 in place.
I've bridged the drain and source of the low-side FETs.
Noticed something. Gate drive is at what it is supposed to be - sharp square waves at 8vrms.
When there is no signal applied to the RCA there is constant 12.57v DC at A high side, as it should be, but at B side it's sitting on the Low side, not at the high one.
In your guide Perry there is a note - Note About High-Side Drive Power Supplies: it is said that only the high sides needs this 12v above positive rail voltage.
Here are the pin voltages without any signal in the rca.
1-12.75
2-12.15
3-0
4-0
5-12.15
6-6.10
7-1.40
8-5.25
9-5.25
10-12.57
11-12.35
12-0
13-0
14-0
15-12.15
16-12.15
17-0
18-12.15
19-0
20-0
Shouldn't pin 11 and 20 - which are A+B High-side Outputs have both 12.15v and not pin 18 which is B Low-side Output ?
HIP4080 in place.
I've bridged the drain and source of the low-side FETs.
Noticed something. Gate drive is at what it is supposed to be - sharp square waves at 8vrms.
When there is no signal applied to the RCA there is constant 12.57v DC at A high side, as it should be, but at B side it's sitting on the Low side, not at the high one.
In your guide Perry there is a note - Note About High-Side Drive Power Supplies: it is said that only the high sides needs this 12v above positive rail voltage.
Here are the pin voltages without any signal in the rca.
1-12.75
2-12.15
3-0
4-0
5-12.15
6-6.10
7-1.40
8-5.25
9-5.25
10-12.57
11-12.35
12-0
13-0
14-0
15-12.15
16-12.15
17-0
18-12.15
19-0
20-0
Shouldn't pin 11 and 20 - which are A+B High-side Outputs have both 12.15v and not pin 18 which is B Low-side Output ?
"All drives should be sitting on ground with the low-side G-S shorted." - the picture above shows DRAIN - SOURCE shorted, not Gate-Source. I'm confused...even in the guide it says "Below, pads 2 and 3 for Q12C are bridged with solder " so that's drain and source.
Do you have the equivalent of IC4C shorted? - no, do I need to ?
Pre-amp section is working fine, why do i have to drive the 4080 directly ?
Do you have the equivalent of IC4C shorted? - no, do I need to ?
Pre-amp section is working fine, why do i have to drive the 4080 directly ?
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Sorry. That should be d-s as shown in the photos.
Shorting the op-amp pins will close the feedback loop locally. Without the short, the op-amp output could be virtually anything. With the short, it should bring the voltage to the same as the non-inverting input which should be the same as pin 6 of the 4080.
At this point, you don't need to drive the 4080 directly. The triangle waveform on pin 6 of the 4080 and the straight DC on pin 7 should provide all of the drive you need.
Shorting the op-amp pins will close the feedback loop locally. Without the short, the op-amp output could be virtually anything. With the short, it should bring the voltage to the same as the non-inverting input which should be the same as pin 6 of the 4080.
At this point, you don't need to drive the 4080 directly. The triangle waveform on pin 6 of the 4080 and the straight DC on pin 7 should provide all of the drive you need.
Do you have the equivalent of IC4C shorted? - I've just did.
It is self-oscillating at 65khz with duty cycle of 40% for the low side and 60% for the high side. Don't know if that's okay.
But when i remove the short from IC4C and play 50hz sinewave to the rca - all gates have 50% duty cycle, low and high.
So i suppoose it's alright ?
Time to buy some IRF3710Z...
It is self-oscillating at 65khz with duty cycle of 40% for the low side and 60% for the high side. Don't know if that's okay.
But when i remove the short from IC4C and play 50hz sinewave to the rca - all gates have 50% duty cycle, low and high.
So i suppoose it's alright ?
Time to buy some IRF3710Z...
Please don't post in a repair thread that was started by someone else unless you are trying to help them.
Start a new thread if you need help with a repair of your own.
http://www.bcae1.com/temp/newthreaddiy01.png
Start a new thread if you need help with a repair of your own.
http://www.bcae1.com/temp/newthreaddiy01.png
Pin 6 has wave at 65khz at 6.08vrms
Pin 7 is straight DC at 6.48vrms.
IC4C has the 6.48vrms at all pins except Vcc- (ground) and Vcc+(+12v).
Another bummer...
I have fitted another HIP4080 (new one but it's not really from a reputable source) and one IRF3710Z per bank.
It was working as intended, there was audio and sinewave was clean.
Then i fitted all 12 mosfets (3 per bank) and....the second I've turned the amp on and relay has clicked - the hip4080 got hot and died, taking some mosfets out with it. There wasn't even a high current draw, something like 4-5 amps for couple of seconds.
The IRF3710Z are genuine 100%, as they come from reputable source and I've used them in many other hip based amps with no problems.
The HIP4080 i have my doubts.
So i think i had enough of this amp, i'm going to give up on this one, I don't like burning more money in this.
I have fitted another HIP4080 (new one but it's not really from a reputable source) and one IRF3710Z per bank.
It was working as intended, there was audio and sinewave was clean.
Then i fitted all 12 mosfets (3 per bank) and....the second I've turned the amp on and relay has clicked - the hip4080 got hot and died, taking some mosfets out with it. There wasn't even a high current draw, something like 4-5 amps for couple of seconds.
The IRF3710Z are genuine 100%, as they come from reputable source and I've used them in many other hip based amps with no problems.
The HIP4080 i have my doubts.
So i think i had enough of this amp, i'm going to give up on this one, I don't like burning more money in this.
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