Hey all. I'm building an Aleph 5 kit. Mr. Pass specifies 34VDC for the rails. How high can I push the rail voltage? I have a 30V transformer which will give me around 42VDC after rectification and wanted to know if it is going to work without stressing the MOSFETs? Also would it increase the temperature of the MOSFETs if I use higher voltages? Thanks for any feedback.
Is that the power supply voltage under full loading from the biased output stage, or is that just open circuit?
Most power transformers will sag 10% or so under full rated loading.
Most power transformers will sag 10% or so under full rated loading.
So how bad is it to run the amp with lets say 40-41 volts instead of the recommended 34? Also would it increase the FETs temperature? I'm just trying to use my existing transformers. If needed, I can purchase lower voltage transformers.
Aleph 5, heat per channel being 150W ....... you will not get more than 38Vdc per rail
just go for it
when you can, double capacitance
just go for it
when you can, double capacitance
This program is fun to play with. If you are using a CRC or a CRCRC power supply, you can change the resistor value and see the resulting voltage under load.
If you go to the Aleph UMS thread, there are some screenshots that you can use as a reference
https://www.duncanamps.com/psud2/
If you go to the Aleph UMS thread, there are some screenshots that you can use as a reference
https://www.duncanamps.com/psud2/
P = V x I
Increasing V by 20% (with the same output bias current I) means Tj will increase, by around a few degrees C.
But who besides NP actually knows how the circuit will react to a higher than design power supply voltage?
Copy all and thanks! I'm not sure why my FETs are getting so hot then. They run at 229F which is too hot! I might increase my heat sink size or even adding a fan.
you're building, and mosfets are already hot?
is there something, which you didn't fully explained ?
pics
is there something, which you didn't fully explained ?
pics
I have completed the PCB for the single channel and doing testing. Still need to complete the rest and the enclosure!
From the manual.
"The heat sinks will warm up in about an hour to a temperature which will not be comfortable to touch for more than a moment or two, which is 120 to 130 degrees Fahrenheit (50 to 55 degrees Celsius). "
"The heat sinks will warm up in about an hour to a temperature which will not be comfortable to touch for more than a moment or two, which is 120 to 130 degrees Fahrenheit (50 to 55 degrees Celsius). "
I don’t think all that heat is going to make it to the sinks.
Yeah, that's a pretty inefficient arrangement for dissipating the device heat.
Even a fan may not help any. Those mechanical junctions will not transfer
heat very well, being far from flat, and inserting a long distance from devices to fins.
Unless a thermocouple right on the device tab gives a reasonable value after thermal
stabilization, I would not trust this.
Even a fan may not help any. Those mechanical junctions will not transfer
heat very well, being far from flat, and inserting a long distance from devices to fins.
Unless a thermocouple right on the device tab gives a reasonable value after thermal
stabilization, I would not trust this.
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With a heat spreader (piece of 3/8" aluminum) and thermal goop on the contact surfaces between the heatsink, angle plate etc, you may be able to accomplish an Aleph Mini with that. I have the schematics in case you want alter your PCBs to try it.
keep fire extinguisher near
when you're tired of cleaning the house of white powder, go back and start thread asking for help in determining which arrangement of casing da beast is most adequate for your wallet
in most cases, finishing mental image of project is serious ping-pong, except if you can lean on experience of people already doing the same
in game you chose, saving the money is possible only if you have serious mileage, or you're able to collaborate with someone having it
that, shown on pics, is result of none of above
but, don't fret, we all did it...... that's how you get to mileage
when you're tired of cleaning the house of white powder, go back and start thread asking for help in determining which arrangement of casing da beast is most adequate for your wallet
in most cases, finishing mental image of project is serious ping-pong, except if you can lean on experience of people already doing the same
in game you chose, saving the money is possible only if you have serious mileage, or you're able to collaborate with someone having it
that, shown on pics, is result of none of above
but, don't fret, we all did it...... that's how you get to mileage