I don't think I changed any other parts, but if I remember any I'll tell you. Be careful selecting the right parts sizes and formats for the PCBs - I had some too large capacitors, wrong format potentiometer, etc.
I also re-built the amp with slightly different mounting configuration, to allow direct mounting of Mosfets to a flat heatsink:
I would maybe want to try a slightly different combination of resistors for the biasing circuit, to allow easier adjustment with the IRF devices. But the values in Anthony's schematic work fine.
I also re-built the amp with slightly different mounting configuration, to allow direct mounting of Mosfets to a flat heatsink:
An externally hosted image should be here but it was not working when we last tested it.
I would maybe want to try a slightly different combination of resistors for the biasing circuit, to allow easier adjustment with the IRF devices. But the values in Anthony's schematic work fine.
Resistor Values
I can't seem to find the wattage for the resistors in his manual. I found all the resistance for each but not sure if they should be 1/4 watt, 1/2 watt, or 1 watt, ect, ect.
I can't seem to find the wattage for the resistors in his manual. I found all the resistance for each but not sure if they should be 1/4 watt, 1/2 watt, or 1 watt, ect, ect.
In my amp R7 and R14 (both 10k) are 1 watt metal film. R24-31 (0.22 ohm) are 5 watt wirewound (sandcast?), but 3 watt non-inductive resistors would work too if you can get them. All the rest are 1/4 watt.
The Av400 was designed so it didn't require a zobel nework on the output.
It is uncondiftional stable into any load from 4 to 16 Ohms
It is 2 Ohm stable but is not recommended...
It is uncondiftional stable into any load from 4 to 16 Ohms
It is 2 Ohm stable but is not recommended...
hello saint,
I'm planning to build ur amp design soon av400/av800, because I heared it is sounding good. I have a question, what is the total output power of av400 if I connect in bridge mode.
I have a simple calculation to find the output power bridge mode type as follows!!!.
bridge mode type.
@ 16 ohms=400 watts
@ 8 ohms =800 watts
@ 4 ohms =1200 watts--- it is possible to connect in 4 ohms load?
many thanks,
rlg
I'm planning to build ur amp design soon av400/av800, because I heared it is sounding good. I have a question, what is the total output power of av400 if I connect in bridge mode.
I have a simple calculation to find the output power bridge mode type as follows!!!.
bridge mode type.
@ 16 ohms=400 watts
@ 8 ohms =800 watts
@ 4 ohms =1200 watts--- it is possible to connect in 4 ohms load?
many thanks,
rlg
I have tested the AV400 in bridge mode with a single 625VA transformer. It produced 700 watts RMS into 8 Ohm load.
Driving a 4 Ohm load with this amp is not recommended.
However it is possible with a lower supply rail.
Say +-50 volts
Have fun
Driving a 4 Ohm load with this amp is not recommended.
However it is possible with a lower supply rail.
Say +-50 volts
Have fun
Well why not try Greg's GB300D SKA amp?
He rates it quite conservatively at 300Wrms into 8 ohms or 4 ohms, but it uses 1200W of complementary MOSFETs in the outputs.
That's enough for over 400Wrms in other amps. He has a sub crossover circuit as well.
He rates it quite conservatively at 300Wrms into 8 ohms or 4 ohms, but it uses 1200W of complementary MOSFETs in the outputs.
That's enough for over 400Wrms in other amps. He has a sub crossover circuit as well.
hello' guys'
pls. help, I just built av400 I make my own pcb of this version. my problem is during pre test the amp is ok. it read 1.6 vot at R2 , R4, but when I put the power mosfet the fuse was blow.
anyone can help, I expect that the op is damage. but I dont know on how to check the mosfet.
rlg.
pls. help, I just built av400 I make my own pcb of this version. my problem is during pre test the amp is ok. it read 1.6 vot at R2 , R4, but when I put the power mosfet the fuse was blow.
anyone can help, I expect that the op is damage. but I dont know on how to check the mosfet.
rlg.
rlg_200 said:hello' guys'
pls. help, I just built av400 I make my own pcb of this version. my problem is during pre test the amp is ok. it read 1.6 vot at R2 , R4, but when I put the power mosfet the fuse was blow.
anyone can help, I expect that the op is damage. but I dont know on how to check the mosfet.
rlg.
mosfets, gets easily zapped when there is nothing at the gate, i learn'ed that the hard way. make sure gate biasing is ok, and set not to high.
if fuse blows, check the mosfets drain and source, it shuld be a diode forward biased one side and infinitely high reistance at the other side, that is when using your ohmmeter when cheking.
😀
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