Hi Mainframe,
thanks for your very rapid and professional response. I appreciate the links to the appropriate posts and the fact that your answer is based on experience. I am very satisfied with the information received, but would appreciate your response to my question about recommendations for main filter capacitors. I am looking for good capacitor types for 54 V rail voltage with reasonable prices. Proposals by other members are also welcome.
Regarding my question 1, I found that when using separate rectifier bridges for each rail voltage, the transformer secondary wingings are galvanically connected only during the capacitor charging pulses, i.e. during a small part of each cycle depending on power supply loading. In case of a single rectifier bridge common for both rails the transformer wingings are continuously solidly connected to the common ground. In addition the transformer winding voltages behave differently. In the case of separate bridges, the voltages of the windings follow each other with a continuous difference, which is the rectified peak voltage. In case of a common bridge, the voltages of the winding ends connected to the rectifier bridge vary in opposite directions between the positive and negative rectified peak voltage. These two facts might cause some difference in performance, which is difficult to reveal by simulations.
Regards
Martant
thanks for your very rapid and professional response. I appreciate the links to the appropriate posts and the fact that your answer is based on experience. I am very satisfied with the information received, but would appreciate your response to my question about recommendations for main filter capacitors. I am looking for good capacitor types for 54 V rail voltage with reasonable prices. Proposals by other members are also welcome.
Regarding my question 1, I found that when using separate rectifier bridges for each rail voltage, the transformer secondary wingings are galvanically connected only during the capacitor charging pulses, i.e. during a small part of each cycle depending on power supply loading. In case of a single rectifier bridge common for both rails the transformer wingings are continuously solidly connected to the common ground. In addition the transformer winding voltages behave differently. In the case of separate bridges, the voltages of the windings follow each other with a continuous difference, which is the rectified peak voltage. In case of a common bridge, the voltages of the winding ends connected to the rectifier bridge vary in opposite directions between the positive and negative rectified peak voltage. These two facts might cause some difference in performance, which is difficult to reveal by simulations.
Regards
Martant
If its difficult to see in a sim, its probably impossible to see in the final product. If you've got the coin and the room, go dual bridges. Otherwise don't, its not really gonna affect much. You certainly wont hear it. But if you're already in thought this deep, its gonna bug you either way you go 😛
Rail caps depends on how you want to fit out your chassis. If you go snap in, you'll need a PCB. here's a nice compact solution, but there are thousands out there; https://www.diyaudio.com/community/threads/lt4320-based-active-rectifier.336572/post-6233338. If you dont want a PCB and prefer point to point wiring, you'll need screw caps or similar. I think most people go PCB's with snap-in caps, and in that case the best value cap is this guy here https://www.mouser.com/ProductDetail/Chemi-Con/ESMH800VSN103MA50S?qs=xI6Y96ivSIyl3%2BiMJta85A==
Rail caps depends on how you want to fit out your chassis. If you go snap in, you'll need a PCB. here's a nice compact solution, but there are thousands out there; https://www.diyaudio.com/community/threads/lt4320-based-active-rectifier.336572/post-6233338. If you dont want a PCB and prefer point to point wiring, you'll need screw caps or similar. I think most people go PCB's with snap-in caps, and in that case the best value cap is this guy here https://www.mouser.com/ProductDetail/Chemi-Con/ESMH800VSN103MA50S?qs=xI6Y96ivSIyl3%2BiMJta85A==
Hi Martant
Dual bridge rectifiers with the psu 0V connection after the bridges and after the capacitors helps to keep away the high current capacitor charging pulses from the area where the amplifier connects to the power supply.
- Dan
Dual bridge rectifiers with the psu 0V connection after the bridges and after the capacitors helps to keep away the high current capacitor charging pulses from the area where the amplifier connects to the power supply.
- Dan
V5 is alive!
The first EF3-4 V5 mirrored stereo set has received full voltage and biased up like a dream. Excuse the workshop dust, cat hair and solder flux on the output transistors it was getting late!
Passed all initial power up and warm up tests no issues at all. Huge thanks to the team for putting together, and meticulous QA, of the schematic and PCB and BOM @stuartmp @danieljw @Harry3 @jjs so that when I powered it up (very cautiously) it didn't splode or smoke. EF3-3 and EF3-5 builds to follow.
The first EF3-4 V5 mirrored stereo set has received full voltage and biased up like a dream. Excuse the workshop dust, cat hair and solder flux on the output transistors it was getting late!
Passed all initial power up and warm up tests no issues at all. Huge thanks to the team for putting together, and meticulous QA, of the schematic and PCB and BOM @stuartmp @danieljw @Harry3 @jjs so that when I powered it up (very cautiously) it didn't splode or smoke. EF3-3 and EF3-5 builds to follow.
Hi Mainframe and danieljw,
thanks again for good and valuable advice. Anyway I have noted the importance of avoiding the disturbance caused by charging current peaks. I believe that correct details of the power supply topology is the most important thing for this. In my previous amplifiers I have not faced any problems related to this issue.
Regards
Martant
thanks again for good and valuable advice. Anyway I have noted the importance of avoiding the disturbance caused by charging current peaks. I believe that correct details of the power supply topology is the most important thing for this. In my previous amplifiers I have not faced any problems related to this issue.
Regards
Martant