Wondering if anyone has pics of the power supply section of this amp?
I recieved this amp in bad condition there is caps missing, and the gate resistors have been cobbled.
The board says 75 ohm resistors but i think they put a differnt value in them during production
There are 1/8 watt and a 1/4 resistor tied together in the amp right now and the value is 240 ohms so wondering if anyone knows what value the gate reisitors need to be
I recieved this amp in bad condition there is caps missing, and the gate resistors have been cobbled.
The board says 75 ohm resistors but i think they put a differnt value in them during production
There are 1/8 watt and a 1/4 resistor tied together in the amp right now and the value is 240 ohms so wondering if anyone knows what value the gate reisitors need to be
They are using buz102's for the power supply fets wondering if you might know what gate resistors i should put in this amp cause like i said someone tied 2 resistors together and came up with 240 ohms total for the gate resistors
What's more important is what sub you're going to use. If the FETs have not failed, a 100 ohm would probably work but the 75 ohm would definitely be a good, safe value.
Not sure what subs hes going to use all the fets are good in the amp so if i put 75 ohm resistors in the amp he should be good on any sub he decides to run?
The gate resistors have nothing to do with the speaker load. If they're too high in value, they FETs will likely fail even without a speaker load. The 75 ohm resistors should be a safe value.
When you get the amp up and running, make sure the idle current isn't excessive. If it doesn't seem excessive, turn the DC voltage on the power supply down to ~11v. If the idle current increases when you reduce the DC voltage, there is a problem. If the idle current remains the same or decreases when you lower the DC voltage, everything is likely OK.
When you get the amp up and running, make sure the idle current isn't excessive. If it doesn't seem excessive, turn the DC voltage on the power supply down to ~11v. If the idle current increases when you reduce the DC voltage, there is a problem. If the idle current remains the same or decreases when you lower the DC voltage, everything is likely OK.
Hi Perry,
I opened up a Hifonics gen x thor amp and they are running the same fets as the zeus but the gate resistors that they used in that amp(thor) are 47 ohm
Says the same on the board 75 ohm but right from the factory they had 47 ohm gate resistors in it.
Wondering if i can put the 47 ohm gate resistors in the zeus amp and be fine
I opened up a Hifonics gen x thor amp and they are running the same fets as the zeus but the gate resistors that they used in that amp(thor) are 47 ohm
Says the same on the board 75 ohm but right from the factory they had 47 ohm gate resistors in it.
Wondering if i can put the 47 ohm gate resistors in the zeus amp and be fine
Ok I talked to one of the designers on this amp and he said the 47 ohm gate resistors wont work it will turn the amp on the supply to fast and wont shut down fast enough or something like that. And he said ill get whats called a crossfire in the supply.
He said he couldnt remember what they used but it ws either a 220 ohm or a 240 ohm resistor for the gates
Wondering what would be better the 220 or 240 ohm?
He said he couldnt remember what they used but it ws either a 220 ohm or a 240 ohm resistor for the gates
Wondering what would be better the 220 or 240 ohm?
There's virtually no way for the 220 ohm resistors to work. You stated that you opened an amp that used the same FETs and used 47 ohm resistors so it's obvious they will work.
I think he meant cross-conduction which is more likely to occur with a gate resistor with too much resistance.
In some amps, there are resistors connected to the gate resistors that can have values between 100 and 220 ohms. These are pull-down resistors.
What FETs are being used in this amp?
I think he meant cross-conduction which is more likely to occur with a gate resistor with too much resistance.
In some amps, there are resistors connected to the gate resistors that can have values between 100 and 220 ohms. These are pull-down resistors.
What FETs are being used in this amp?
Is this a ZED designed amp?
If so, they did use 220 ohm resistors at least up to the series 7 amps but they set the dead-time higher than normal so that there would be no cross conduction.
If so, they did use 220 ohm resistors at least up to the series 7 amps but they set the dead-time higher than normal so that there would be no cross conduction.
They are using buz 102's for the power supply fets.
Right now they have a 165 ohm and a75 ohm resistor tied together for the gate resistors
Right now they have a 165 ohm and a75 ohm resistor tied together for the gate resistors
yes this is a zed made amp heres a pic of the gates some one put in =240 ohms. I think they are suppose to be 220 ohm resistors since he was talking about the dead time and telling me the reason they used so high of a value in them is to slow down the supply like the amp wont turn on so fast
It would make the FETs turn on/off more slowly and could have been done to prevent ringing on the power supply transformer. To make the amp turn on more slowly, he likely would have used one of the inputs on the 494.
That means it very likely has dead-time built in and the 220 ohm resistors may be the correct value.
After replacing the resistors, remember to confirm that the idle current doesn't increase when you reduce the 12v supply voltage to ~11v.
After replacing the resistors, remember to confirm that the idle current doesn't increase when you reduce the 12v supply voltage to ~11v.
ok i replaced all the gate resistors 18 of them.
i was checking the rectifiers and found one with the leads broke off
its a fes16jt wondering where i can find theese since the only thing i have laying around is a mur815 and dont think that will work
i was checking the rectifiers and found one with the leads broke off
its a fes16jt wondering where i can find theese since the only thing i have laying around is a mur815 and dont think that will work
If the rail capacitors are rated for 75v or less, the MUR815 may work (it's rated for 150v). The original is rated for 600v. The replacement doesn't need to be rated for 600v but should be rated for at least 2x the rail voltage (measured rail to ground).
If you can get the amp to power up, you can measure the rail voltage. Measure from the positive rail to a non-bridging speaker terminal and from the negative rail to a non-bridging speaker terminal.
If you can get the amp to power up, you can measure the rail voltage. Measure from the positive rail to a non-bridging speaker terminal and from the negative rail to a non-bridging speaker terminal.
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