Low noise linear PSU for the Soekris DAM1021

Which one?

  • LDOVR

    Votes: 4 44.4%

  • Sjöström

    Votes: 0 0.0%

  • DIYINHK

    Votes: 0 0.0%

  • Salas

    Votes: 4 44.4%

  • Other

    Votes: 1 11.1%
  • Total voters
    9
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zgtc

zgtc

Member
Joined 2016
Hi all,

I intend to build a DAC based on RPi + Soekris DAM1021. I already have the RPi PSU. I am now looking for a low noise linear PSU for the DAM (+-9to12V DC). I've seen some that might fit, but I don't know the pro's and con's among them. Would you be so kind to recommend (even another not in the list)?

LDOVR Dual Polarity TPS7A4700/3301 Ultra Low Noise Power Supply

Sjöström SSR03 Super Regulator Power Supply

DIYINHK 0.56uV Ultralow noise DAC power supply regulator +-9/12/15V 1.5A*2

Salas SSLV1.3 UltraBiB shunt regulator


I'm not even sure all of them are really on sale, so I'm that lost

Thank you so much
Sergi
 
JonSnell Electronic

JonSnell Electronic

Member
Joined 2012
jonsnell.co.uk
Digital using TTL and Cmos has a 30/60% threshold meaning if it works on 5volts, if the pulse is less that 1.5volts it is off, more than 3.0volts and it is on. So I fail to see the need to waste money on ultra quiet regulated power supplies. It is digital and not analogue. When you get to the analogue stage, as long as the thresholds are not exceeded, more than 90% of rail voltage, it makes no difference there either.
 
zgtc

zgtc

Member
Joined 2016
JonSnell Electronic said:
Digital using TTL and Cmos has a 30/60% threshold meaning if it works on 5volts, if the pulse is less that 1.5volts it is off, more than 3.0volts and it is on. So I fail to see the need to waste money on ultra quiet regulated power supplies. It is digital and not analogue. When you get to the analogue stage, as long as the thresholds are not exceeded, more than 90% of rail voltage, it makes no difference there either.
Click to expand...

Sorry I missed that background info. I've read the manual, and even if Soeren states that you do not need to regulate the input, absolutely everyone says that a low noise linear PSU improves the sound. I appreciate your answer in any case.
 
zgtc

zgtc

Member
Joined 2016
jan.didden said:
Another option is a SilentSwitcher: The SilentSwitcher | Linear Audio NL
Scroll down for some data graphs.

Extremely low noise very low output impedance, totally mains free if you want so. Bipolar & low voltage for your digital circuits.

Jan
Click to expand...

Hi Jan,

More options! Good. Would the SS deliver enough power for both a Soekris (0.18A @ +10V and 0.06A @ -10V ) and a RPi (1/1.5A @ 5V), plus a safety margin?

Thank you
 
jan.didden

jan.didden

AX tech editor
Joined 2002
linearaudio.net
Paid Member
zgtc said:
sorry you must have missed post #6 with the Qs:

Would the SS deliver enough power for both a Soekris (0.18A @ +10V and 0.06A @ -10V ) and a RPi (1/1.5A @ 5V), plus a safety margin?

TY!
Click to expand...

Sorry yes missed those.

For the +/-10V that's OK, but the 1.5A may be pushing it when powered from a USB charger or power bank.
Unless you can power it from a 8-10V wallwart, then it would be OK.

Jan
 
zgtc

zgtc

Member
Joined 2016
jan.didden said:
Sorry yes missed those.

For the +/-10V that's OK, but the 1.5A may be pushing it when powered from a USB charger or power bank.
Unless you can power it from a 8-10V wallwart, then it would be OK.

Jan
Click to expand...

Great, just to be sure I'm on the same page. If I power the SS from a 4A@9V DC walmart I could make the SS to deliver enough power for both a Soekris (0.18A @ +10V and 0.06A @ -10V ) and a RPi (1/1.5A @ 5V), plus a safety margin. Is that OK?

Also, how does the SS manage the heat dissipation?

thank you!
 
jan.didden

jan.didden

AX tech editor
Joined 2002
linearaudio.net
Paid Member
Yes that should be fine. I will send you the resistor values to set the output to +/-10V. You should check whether that +/-10 is determined by the available voltage in that project or whether it is necessary. If there are opamps you could leave it at +/-15 or +/-12 for a bit more performance.

The SS has very low dropout linear post regulators that work with just 0.3V of headroom. I set the switcher to provide about 0.5V more to the linear regs than the required output so the dissipation in the linear regs is minimal.
Of course the switcher is very high efficiency on itself.

Jan
 
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