im trying to build a subwoofer amp using Kypton V2 so im thinking of using Hexfets 5 pairs IRFP240 for 320RMS into 4ohms so what are the voltage rails that I should be using+/-65?
As said mosfets require more voltage than bipolars for equivalvent output.
As said mosfets require more voltage than bipolars for equivalvent output.
320W into 4ohms requires an output of 50.6Vpk
Allowing about 15V for losses through the amplifier and droop in the supply rail should get fairly close.
Your guess of ±65 should be around the lower limit to hit that 320W target.
Try a dual 50Vac transformer.
Allowing about 15V for losses through the amplifier and droop in the supply rail should get fairly close.
Your guess of ±65 should be around the lower limit to hit that 320W target.
Try a dual 50Vac transformer.
Yes, rail droop is a good point, and then we come to a question - what exactly we understand by 320W into 4 ohms. One thing - is handlind a peak of this level - no problem, reservoirs will handle it, OPS will also make it with ease. A very different story - running a sine wave constantly during the day 🙂eek🙂 at this power - resultung in significant rail droop and very different heat dissipation requirements (a good reason for using the fans in pro stage equipment).
Who will listen to low frequency sine waves all day at maximum output?
Music does not put so much strain to the OPS.
I have +-72v supplies in my 5p mt200 amps running Eminence lab12s in 6 ohms. I can run them close to clipping all day playing music without problems.
I run high voltage rails to have headroom for the peaks, not to run sine waves at full power.
Then select a lower vol pot setting so that YOU the operator does not overload the amplifier nor the speaker driver.
i have a doubt regarding the Kypton V2 that why cant it be run till 90V instead stated as 75V and there is still alot of headroom for the VAS transistors.
Hi, Kypton V2 will run fine at 90V, however you will have to adjust the values of R14, R15 at the rails accordingly. And use small local heatsinks on TO-126 devices.
True but what if want to go till +/- 160V as class H driver. Im thinking of using the ksa1381 ksc3503 even for the vas stage transistors that has alot of VCEO headroom. Any opinions?
+/-160V is too much for ksa1381 / ksc3503 - they will see almost rail-to-rail voltage at high swing - more that 300V, dissipating close to 1W each, which is out of SOA for them.
Anyway - what's the reason for having the rails that high?
Anyway - what's the reason for having the rails that high?
OK, Crest 9001 is a pro-grade amplifier, providing up to some 6000W in bridged mode.
Rhythmsandy - are you looking for something of that scale? 😱
Rhythmsandy - are you looking for something of that scale? 😱
Im actually worried about my ground loops.
Tell me one thing what is the use of this two 4148 diodes with 10ohm resistor at the negative input of the amp?
i got a denon 3300W receiver which has pre outs per channel and then used kyptonv2 as amplifier and found that there is some small groundloop issue low in amplitude but still audible from the surround speakers. I have used unbalanced interconnects.
Now when I checked the safety earth pin on the denon receiver i found that there is no third pin so there no scope of ground from there..
But i thought that removing the two 4148 with 10ohm resistor would solve the problem or i dont know why its used?
Once connected to the receiver im getting the ground loop issue but once connected to the PC with soundcard im not getting any hum.
Tell me one thing what is the use of this two 4148 diodes with 10ohm resistor at the negative input of the amp?
i got a denon 3300W receiver which has pre outs per channel and then used kyptonv2 as amplifier and found that there is some small groundloop issue low in amplitude but still audible from the surround speakers. I have used unbalanced interconnects.
Now when I checked the safety earth pin on the denon receiver i found that there is no third pin so there no scope of ground from there..
But i thought that removing the two 4148 with 10ohm resistor would solve the problem or i dont know why its used?
Once connected to the receiver im getting the ground loop issue but once connected to the PC with soundcard im not getting any hum.
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No, it's vice versa. That 10 ohm is arranging so called "lifted ground" for breaking the possible ground loops. The diodes protect it from possible high voltage.
The bottom lead of the resistor is connected to the main ground. The top lead should be connected to the input socket's ground ring only. This ground ring must be isolated from the chassis. So, in the end, the top lead of the resistor is connected to the input cable's ground wire only.
The bottom lead of the resistor is connected to the main ground. The top lead should be connected to the input socket's ground ring only. This ground ring must be isolated from the chassis. So, in the end, the top lead of the resistor is connected to the input cable's ground wire only.
Its done exactly the way you said so even then why am I getting this ground loop?
The sound is not loud but low but disturbing. But why isnt it happening when i connected to the PC soundcard and why its happening when connected to the AV receiver Preouts.
Do i need to increase the resistance from 10ohm to 22ohm or so?
Then we need more information. Do you hear the hum if:
- both inputs are connected to the source (presumably yes)?
- one input is connected, the other one is shorted?
- both inputs are shorted.
Can you draw a sketch of your grounding scheme - all ground connections to every board, every terminal, etc. - every detail is important.
- both inputs are connected to the source (presumably yes)?
- one input is connected, the other one is shorted?
- both inputs are shorted.
Can you draw a sketch of your grounding scheme - all ground connections to every board, every terminal, etc. - every detail is important.
If you see the ground route on the pcb its not loop its said by some pcb designers that it will act like shield but if you loop it then you see group loop so the C shaped route in the ground would help in also some interference as it will guard the interal part of the circuitry as said by an experienced pcb designer.
Let me know if anything is in wrong there.
Let me know if anything is in wrong there.
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This doesn't give too much information. What I mean is a wiring diagram, like the one shown in this article by Rod Elliott:
Power Supply Wiring Guidelines
But also covering all the boards and terminals - what wire goes where. To what exactly point on the board.
Power Supply Wiring Guidelines
But also covering all the boards and terminals - what wire goes where. To what exactly point on the board.
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