switching power supply and analog audio circuits

ericgibbs

Joined Jan 29, 2010
15,526
hi Pete,
The link states:
30 Volt DC 3.0 Amp Dual Output Linear Power Supply

and also
This high stability dual output switch mode bench power supply features.

I would get confirmation before buying.
E
 

ElectricSpidey

Joined Dec 2, 2017
2,146
I wouldn't buy anything from a company with contradicting descriptions.

But the real question is about using a SMPS with audio...well that is a highly debated subject, at the very least I would suggest using a supply that is recommended by people in the audio business, and not some bargain supply.
 

Papabravo

Joined Feb 24, 2006
18,422
I wouldn't buy anything from a company with contradicting descriptions.

But the real question is about using a SMPS with audio...well that is a highly debated subject, at the very least I would suggest using a supply that is recommended by people in the audio business, and not some bargain supply.
This was a concern 50 years ago when switch-mode power supplies used switching frequencies in the audio range. Modern supplies use much higher frequencies and that sort of interference is less of a concern. I have been using a switch-mode power supply for a 100 Watt K3-HF transceiver for a decade, and have experienced absolutely zero problems in weak signal and contesting operations. A similar product should be suitable in the audio relm as well. I agree that this level of performance will not be available in a bargain power supply. It is a DuraComm EH-30, 13.8V@30A supply and cost in the neighborhood o $250.00
 

Irving

Joined Jan 30, 2016
2,668
This PSU, in common with most of its modern siblings, uses a switching flyback buck converter for isolation followed by a linear section for fine voltage control and current limiting, so both descriptions are correct. The output of the switching section is controlled in step with the desired output to minimise losses in the linear section. The <1mV ripple spec (0.5mV RMS) is fine for audio use and anyway any switching noise will be >100kHz. Any good audio design should reject supply rail signalling anyway.
 

upand_at_them

Joined May 15, 2010
896
FWIW, if you're looking for a bench power supply, this one is similar in specs and has been popular with hobbyists. I have been pleased with mine, owned for at least five years. Korad makes an even less expensive model without the programmability (which you probably wouldn't have used anyway), the KA3005D. And an even cheaper model, the KD3005D without any presets, which your posted unit doesn't have either, and is half the price.

https://www.amazon.com/gp/product/B0085QLNFM/
https://www.amazon.com/KORAD-KA3005D-Precision-Adjustable-Regulated/dp/B0084JFWNY/
https://www.amazon.com/KORAD-KD3005D-Precision-Adjustable-Regulated/dp/B00FPU6G4E

Also, take your home address out of your profile. It isn't needed for anything here. While I'm not the paranoid type, you're just giving spam bots (and scam bots) more information about you...people do become victims of identity theft.

Mike
 

Audioguru again

Joined Oct 21, 2019
4,685
The cheap power supply is made for circuit specialists.
Circuit Specialists do not know if it is linear or switching.
The Chinglish manual says it has low noice.
The video shows that one of them works well. Do they all work well?
 

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prepka

Joined Oct 5, 2020
20
The bench power supply that I'm providing a link to looks like a bargain to me. My only reservation is that it is a switching power supply, and I wonder if this type of supply could cause problems with the analog audio circuits that I quite often test. What do you think?

Thanks for your advice in advance,
Pete

https://www.circuitspecialists.com/bench-top-power-supply-csi3003x-5.html
This might be an ok supply for a hobbyist. The guy in the video claims it to be a linear but may have a switcher that feeds a linear regulator. The ambient noise on the scope could be from the power supply as it was on the whole time. Linear supplies are cheap to make but are generally not efficient. I have never heard of this brand and is probably a private label unit from overseas though. What you want is a linear for audio work but the high end switchers I have seen are filtered well enough but cost much more. Without all of the specs on this model it is hard to tell for sure. It could be just fine and it is your choice to make.
 

Thread Starter

PeteHL

Joined Dec 17, 2014
395
This might be an ok supply for a hobbyist. The guy in the video claims it to be a linear but may have a switcher that feeds a linear regulator. The ambient noise on the scope could be from the power supply as it was on the whole time. Linear supplies are cheap to make but are generally not efficient. I have never heard of this brand and is probably a private label unit from overseas though. What you want is a linear for audio work but the high end switchers I have seen are filtered well enough but cost much more. Without all of the specs on this model it is hard to tell for sure. It could be just fine and it is your choice to make.
Thanks for your comments. Instead of the power supply from Circuit Specialists, I'm thinking that I might buy one from Newark made by the well-known manufacturer Tenma. The Tenma supply is a bit more expensive but probably worth it.

https://www.newark.com/tenma/72-8690a/power-supply-2ch-32v-3a-adj-fixed/dp/47X1649

Regards,
Pete
 

upand_at_them

Joined May 15, 2010
896
Thanks for your comments. Instead of the power supply from Circuit Specialists, I'm thinking that I might buy one from Newark made by the well-known manufacturer Tenma. The Tenma supply is a bit more expensive but probably worth it.

https://www.newark.com/tenma/72-8690a/power-supply-2ch-32v-3a-adj-fixed/dp/47X1649
Not trying to dissuade you, but you could get two of the single output Korad units...each of which has 5A of current output. Might be advantageous to have smaller more portable units...one to leave on the workbench and one to take outside (or garage or basement) to do some experiment or somesuch.
 
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