Hi Jan,
I've a quick question. I am using the Super Regulator as a USB power for my DAC and it sounds fantastic! Until now I have used a 1-foot long single pair of wires for the output with the contacts 1 - 2 and 3 - 4 shortened on the board. Today I soldered a new USB adapter with two separate pairs of wires. I did not expect to hear an improvement in the sound quality, but it was substantial.
In this setup, how should I implement the power switch? I cannot do it on the USB adapter, it has to be on the Regulator side, but how do I disconnect two pairs of wires simultaneously?
If I run both pairs through a switch and it disconnects the sensing wire a moment before the power wire, then there might be a voltage spike damaging the DAC.
If I run only the power wire through the switch, then on disconnecting the Regulator would clip and may damage itself.
If instead I run only he input power through the switch, then the DAC is exposed to the output voltage of the Regulator before the output has settled. Can there be an over-voltage at the output on startup? This option has the minimal number of switches, but is it safe? (My power source is a 13V 16AH LiFePO4 battery.)
I guess I can use two switches in sequence. The first one would short the 1 - 2 and 3 - 4 output contacts; the second one would disconnect both output pairs. This would work safely, but is inconvenient with one input and two output switches to be engaged in a given sequence every single time.
What is the best approach here? Thanks so much for your help!
-- Alex
I've a quick question. I am using the Super Regulator as a USB power for my DAC and it sounds fantastic! Until now I have used a 1-foot long single pair of wires for the output with the contacts 1 - 2 and 3 - 4 shortened on the board. Today I soldered a new USB adapter with two separate pairs of wires. I did not expect to hear an improvement in the sound quality, but it was substantial.
In this setup, how should I implement the power switch? I cannot do it on the USB adapter, it has to be on the Regulator side, but how do I disconnect two pairs of wires simultaneously?
If I run both pairs through a switch and it disconnects the sensing wire a moment before the power wire, then there might be a voltage spike damaging the DAC.
If I run only the power wire through the switch, then on disconnecting the Regulator would clip and may damage itself.
If instead I run only he input power through the switch, then the DAC is exposed to the output voltage of the Regulator before the output has settled. Can there be an over-voltage at the output on startup? This option has the minimal number of switches, but is it safe? (My power source is a 13V 16AH LiFePO4 battery.)
I guess I can use two switches in sequence. The first one would short the 1 - 2 and 3 - 4 output contacts; the second one would disconnect both output pairs. This would work safely, but is inconvenient with one input and two output switches to be engaged in a given sequence every single time.
What is the best approach here? Thanks so much for your help!
-- Alex
PS. Another possibility is to use a "make before break" switch at the output that would short the 1 - 2 and 3 - 4 contacts before breaking them from the output, but this would work only if such switches make all contacts before breaking any. Is this if fact how they work or does "make before break" apply to every contact separately? Thanks again!!!
Alex, all good questions. Personally I would switch the input power to the regulator.
There's no danger of an output spike, the superreg comes up well controlled.
If you would want to switch at the output, I would connect the outputs to their respective sense lines, just before the switch, with a small resistor of say 100 ohms.
In that case, if the output is switched off just before the sense, the feedback connection is still intact.
In normal operation, that 100 ohms would be shorted by the direct connection after the switch so would not have any effect.
Hope this helps,
Jan
There's no danger of an output spike, the superreg comes up well controlled.
If you would want to switch at the output, I would connect the outputs to their respective sense lines, just before the switch, with a small resistor of say 100 ohms.
In that case, if the output is switched off just before the sense, the feedback connection is still intact.
In normal operation, that 100 ohms would be shorted by the direct connection after the switch so would not have any effect.
Hope this helps,
Jan
Jan,
I want to build a +/-18V regulator with a 0.3A output for my phono preamp. My power supply will be 2x2 LiFePO4 batteries, just under 27V each side. I understand the voltage math with zenners, references, and resistor dividers; I have only a quick safety question. The plan is that the opamps are 18V max, C2, C6 are 35V, all other caps are 25V, R2, R9 are still 10k. Are these values ideal or do I need to make any changes before ordering parts?
Also, as the batteries discharge, the input voltage will be gradually dropping from 27 toward 20V, but I can recharge them at a certain voltage. What are the ideal and minimum recommended input voltages for the 18V output? Sorry if all this has been asked a million times before
Oh, one more thing. When I connect the input contacts, there is a spark due to C2 charging from the battery. Per your suggestion, I plan to install an input switch. Should I do anything about this rapid charge and spark, like bypassing the switch with a cap or anything else?
Thanks again for your help!
Alex
I want to build a +/-18V regulator with a 0.3A output for my phono preamp. My power supply will be 2x2 LiFePO4 batteries, just under 27V each side. I understand the voltage math with zenners, references, and resistor dividers; I have only a quick safety question. The plan is that the opamps are 18V max, C2, C6 are 35V, all other caps are 25V, R2, R9 are still 10k. Are these values ideal or do I need to make any changes before ordering parts?
Also, as the batteries discharge, the input voltage will be gradually dropping from 27 toward 20V, but I can recharge them at a certain voltage. What are the ideal and minimum recommended input voltages for the 18V output? Sorry if all this has been asked a million times before
Oh, one more thing. When I connect the input contacts, there is a spark due to C2 charging from the battery. Per your suggestion, I plan to install an input switch. Should I do anything about this rapid charge and spark, like bypassing the switch with a cap or anything else?
Thanks again for your help!
Alex
Guys, if you have parts questions, it is helpful to include a schematic. Even if it is the diyaudio store schematic; I get dozens of emails a day and chasing schematics is time consuming and often I find that the member used just a bit different schematic or parts designations which makes for more wasted time.
Many thanks.
Jan
Many thanks.
Jan
Jan, the schematic is here on the second page (sorry, I don’t know how to include it other than as this link):
https://linearaudio.nl/sites/linearaudio.net/files/superreg article V2.3.pdf
-Alex
https://linearaudio.nl/sites/linearaudio.net/files/superreg article V2.3.pdf
-Alex
Your caps are OK. For 18V, a minimum 20V input is enough so no need to recharge the batteries earlier.Jan,
I want to build a +/-18V regulator with a 0.3A output for my phono preamp. My power supply will be 2x2 LiFePO4 batteries, just under 27V each side. I understand the voltage math with zenners, references, and resistor dividers; I have only a quick safety question. The plan is that the opamps are 18V max, C2, C6 are 35V, all other caps are 25V, R2, R9 are still 10k. Are these values ideal or do I need to make any changes before ordering parts?
Also, as the batteries discharge, the input voltage will be gradually dropping from 27 toward 20V, but I can recharge them at a certain voltage. What are the ideal and minimum recommended input voltages for the 18V output? Sorry if all this has been asked a million times before
Oh, one more thing. When I connect the input contacts, there is a spark due to C2 charging from the battery. Per your suggestion, I plan to install an input switch. Should I do anything about this rapid charge and spark, like bypassing the switch with a cap or anything else?
Thanks again for your help!
Alex
No need for special precautions for input switch. The sparks are because when doing it manually there is some jitter on your hands so the contact is also jittering ;-)
Jan
Which LiFePO4 is that? I couldn't find that type. Where did you get it?
Which recharger are you using?
My battery is by Miady. Two in series are close to 27V. Check Amazon and eBay for different models. My charger is: https://www.amazon.com/gp/product/B08MPX414R (4-Stage Automatic 4A LifePO4 Battery Charger by Ultra Power).
What opamp is the best for a +24V regulator for a small preamp https://www.diyaudio.com/community/threads/b1-with-korg-triode.313612 ? I see OPA2604 mentioned earlier in the thread. Any other options? Also, are the same transistors OK or what do they need to replaced them with? Lastly, will it work with a 26V power supply or do I need at least 27V? Thanks!
