Hi,
I have a question regarding proper load capacitance of superreg.
I currently built a 24V version (30V input with ad825) for garage1217 starlight, which has 2x 4700uf input filter cap. I noticed that the superreg is struggling starting up the amp, probably because those caps are too large. Also, it actually might stop working after maybe 10 minutes. The D44H11 is very hot.
I wonder whether I should reduce the input filter cap on the starlight. I originally put those there because I was using a different smps. I happen to have some 10/22uf tantalum and a bunch of aluminum caps around.
I will appreciate some insight into this. Thanks.
I have a question regarding proper load capacitance of superreg.
I currently built a 24V version (30V input with ad825) for garage1217 starlight, which has 2x 4700uf input filter cap. I noticed that the superreg is struggling starting up the amp, probably because those caps are too large. Also, it actually might stop working after maybe 10 minutes. The D44H11 is very hot.
I wonder whether I should reduce the input filter cap on the starlight. I originally put those there because I was using a different smps. I happen to have some 10/22uf tantalum and a bunch of aluminum caps around.
I will appreciate some insight into this. Thanks.
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Thanks for the reply.
The amp was supposed to draw 0.3a maximum under 24V.
I am to drill a few more holes on my enclosure.
BTW in my current setup, the regulator feeds 24v to the amp. I noticed the amp doesn’t get enough voltage for a short while after power switched on. Leds turn on after a few seconds. That’s why i wonder if 2x 4700uf is too much right after Superreg.
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Thanks for the input.
My board is V2.3b. I was using the board in PMillett nuhybrid with no problem.
Anyway I already removed those large inputs and now placed some 100uf in place. It worked better as the charging time is shorter. (And the amp is much more powerful than before! It seems original design's large caps are limiting transient performance with the modified configuration.)
I do need to improve ventilation.
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6V at 300mA is 1.8W, which is not a whole lot but can raise the temp to above 40C. And 40C is a temp that you can just touch for a longer time so it really feels like too hot. Are you using the on-board heatsink for the Superreg? If so, I think you're OK for temperature, just be sure that there's some air circulation space around it.
The slow run-up may be due to the very large capacitors, they need time to charge and during that time the current is high. But it should be over in well under a second unless the transformer output drops during the charging due to heavy load.
But are you sure the current draw is 300mA, is it not more? I would measure the current first. Always measure, always diagnose before randomly making changes!
Jan
I use 6sn7. It should not draw more than a few watt (~5w?). I don’t think the entire circuit would draw too much current. I dropped in 4*100uf, two for amp input and two for grid. Yet it still struggles unless i removed the tube. So i thought the tube has something to do with it.
Temp wise. I used similar heatsink as the store picture shows. Measured temp and it stabilized around 53C with a few more holes drilled in my enclosure. I think i was having issue because of poor ventilation.
PS. I tried Mravlca’s regulator with LT1085on the board. Same problem. However I learned Superreg is way more effective as it filters switching noise without using a huge input cap in the regulator board, which downgraded the sound a bit.
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You really need to measure the current, you are guessing, and that 53C doesn't jive with 300mA, IF the input-output diff on the reg is 6V. Measure that too.
You can measure the current by placing a 1 ohm resistor in series with the 24V feed and measure the voltage across it. 1V = 1A. 100mV = 100mA. Etc, thanks to Mr. Ohm.
Really.
And of course the tube has something to do with it - that's the load you power!
Jan
You can measure the current by placing a 1 ohm resistor in series with the 24V feed and measure the voltage across it. 1V = 1A. 100mV = 100mA. Etc, thanks to Mr. Ohm.
Really.
And of course the tube has something to do with it - that's the load you power!
Jan
Will do and report back later. Now, the amp turns on a while after being switched on and plays fairly well.
But my previous power supply is merely a 24V/1.33A one. There is a chance it went over the 1A limit. However, I start to think it could be my input.... my current 30V input is also a 30W model. Superreg LED will shut off when the amp switched on but recovers later with the amp.
But my previous power supply is merely a 24V/1.33A one. There is a chance it went over the 1A limit. However, I start to think it could be my input.... my current 30V input is also a 30W model. Superreg LED will shut off when the amp switched on but recovers later with the amp.
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@Jan, peranders
I figured out the issue. It was a false alarm due to my delusion. I thought my 30V PSU is a 30W model, but it tunrs out to be 18W one (Thanks for tipping me on power draw, Jan). I put a 36V 30W one on and all alnormality is gone.
Thanks for the input!
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Breaking news!
Breaking news: This has been addressed in detail, just 20 years ago. See this link Subhead "Just How Does it Start"
Breaking news: This has been addressed in detail, just 20 years ago. See this link Subhead "Just How Does it Start"
Read the comprehensive testing article by Jack Walton.
https://linearaudio.nl/sites/linearaudio.net/files/v4 jdw.pdf
Color figures here:
The Superregs | Linear Audio NL
Jan
Hi would the super regulator be good for the Khadas tone board dac it needs 5.5v single supply if you dissconnect the usb c power on the board to power it separately.
so i would just build the positive side .
there is also an alternative ready built TPS7A4700 Ultralow-noise (4µVrms)
TPS7A4700 Ultralow-noise (4mVrms) Power Supply 1.4-20.5V,1A for Audio DAC | eBay
but which one would be best to use ?
so i would just build the positive side .
there is also an alternative ready built TPS7A4700 Ultralow-noise (4µVrms)
TPS7A4700 Ultralow-noise (4mVrms) Power Supply 1.4-20.5V,1A for Audio DAC | eBay
but which one would be best to use ?
Walt, please correct me if I'm wrong.
The facts that were being told didn't seem similar to those problems you dealt with with regulators that were not turning on? Or these were different?