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DIY Stompboxes => Building your own stompbox => Topic started by: slowpogo on September 09, 2019, 01:55:49 AM

Title: Recommend a decent bench power supply for audio projects?
Post by: slowpogo on September 09, 2019, 01:55:49 AM
I did a search but the last thread like this I found was several years old. I'm looking for a bench supply for not just building pedals, but headphone amps, DACs, etc.  What do you guys use, what is worth buying these days?  I'd like something at least 24V/2A and hopefully around $50 or less.  This one on Amazon seems popular but I'm interested in recommendations:

https://www.amazon.com/Eventek-KPS305D-Adjustable-Switching-Regulated/dp/B071RNT1CD/ref=sr_1_2_sspa?keywords=bench+power+supply&qid=1568007959&s=gateway&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzVUgwSlFQNENaWVMzJmVuY3J5cHRlZElkPUEwMTY5NTM5MUtNSjUzOUVFQjk1WiZlbmNyeXB0ZWRBZElkPUEwNTI4MDY2UENZT1AyWkExQTJEJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: yanng45 on September 09, 2019, 06:20:11 AM
Wel i actually use this one : https://www.amazon.fr/gp/product/B07D34VRCH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 (https://www.amazon.fr/gp/product/B07D34VRCH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)

It's probably the same as the one you mentionned, just a different brand. Can't say much about it really, it does what it says, it seems precise enough and i had 0 problem with it in the couple years i used it. I don't "push it" really far tho, usually 9-18V with a couple hundreds milliamps at most !
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: slowpogo on September 10, 2019, 12:22:06 PM
Thanks, good to know that one's been working out for you.  I'll probably just go that route.
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: Digital Larry on January 17, 2021, 02:15:58 PM
@slowpogo I am wondering what you eventually settled on.

I know this topic is semi zombie but I had the exact same question.  Identical!  Well, except I think I could probably be OK with +/- 12 or 15 at 500 mA per side with adjustable current limiting and voltage/current metering.

Thanks,

DL
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: antonis on January 17, 2021, 05:20:37 PM
Larry, I shouldn't use a switching PS for audio projects.. :icon_wink:
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: GibsonGM on January 17, 2021, 05:38:47 PM
Quote from: antonis on January 17, 2021, 05:20:37 PM
Larry, I shouldn't use a switching PS for audio projects.. :icon_wink:

Not without additional filtering, anyway...
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: garcho on January 17, 2021, 05:45:31 PM
check out Graham Hinton's posts on Muffwiggler
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: slowpogo on January 17, 2021, 11:36:47 PM
Quote from: Digital Larry on January 17, 2021, 02:15:58 PM
@slowpogo I am wondering what you eventually settled on.

I know this topic is semi zombie but I had the exact same question.

I went with this Tacklife, it's worked out great so far:
https://www.amazon.com/Switching-Regulated-temperature-protection-Alligator/dp/B07JQXQ8S5/ref=sr_1_3?dchild=1&keywords=tacklife+bench+power&qid=1610944555&sr=8-3
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: anotherjim on January 18, 2021, 06:30:13 AM
We can't continue to avoid switch-mode power supplies - it's the way the whole world is going. Filter it!
Although, the way the world is going, you may have to use a bicycle driving a scavenged alternator.  ::)
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: GibsonGM on January 18, 2021, 06:41:32 AM
Quote from: anotherjim on January 18, 2021, 06:30:13 AM
We can't continue to avoid switch-mode power supplies - it's the way the whole world is going. Filter it!
Although, the way the world is going, you may have to use a bicycle driving a scavenged alternator.  ::)


It worked on the island, and Gilligan had no problem riding that stationary bike for hours and hours...(age check)
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: duck_arse on January 18, 2021, 08:52:33 AM
Quote from: GibsonGM on January 18, 2021, 06:41:32 AM
Quote from: anotherjim on January 18, 2021, 06:30:13 AM
We can't continue to avoid switch-mode power supplies - it's the way the whole world is going. Filter it!
Although, the way the world is going, you may have to use a bicycle driving a scavenged alternator.  ::)


It worked on the island, and Gilligan had no problem riding that stationary bike for hours and hours...(age check)

yes, but have you checked the quality of the local coconuts recently?
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: Digital Larry on January 18, 2021, 09:15:36 AM
Out of curiosity, are the SMPS vs. linear arguments being made practical or theoretical?

e.g.  you had an SMPS and it was too noisy for casual audio design work?

I'm sure some are better than others, whether linear or switching.  Are the ripple/noise specs accurate?

It's not a big deal either way, I found a linear PS in the range I was expecting and will probably get that anyway.
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: GibsonGM on January 18, 2021, 01:51:53 PM
Quote from: Digital Larry on January 18, 2021, 09:15:36 AM
Out of curiosity, are the SMPS vs. linear arguments being made practical or theoretical?

e.g.  you had an SMPS and it was too noisy for casual audio design work?

I'm sure some are better than others, whether linear or switching.  Are the ripple/noise specs accurate?

It's not a big deal either way, I found a linear PS in the range I was expecting and will probably get that anyway.

I'd say it's a practical issue, but I'm not a design engineer, Larry, I just build stuff.  I'd pop a fair value R and C in there...100R, with a 470u and 100n in parallel to ground, and see what I got (for both ripple and 'noise', perhaps).  I've solved a 'whiny' power supply this way numerous times.   If it cured whatever issue, I'd make it permanent within the supply if possible...generally speaking, the switching supply will have a much higher switching frequency than the audible (to very few) 20kHz.    But a poor design *could* create harmonics that are audible.   Some more filtering typically solves the problem.  If it was a wall-wart brick type, including those external components may be a pain in the ass every time you use it.   A real bench-top supply, you should be able to find a nice one and it sounds like you did!
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: Digital Larry on January 18, 2021, 02:20:03 PM
Well, I'm still looking.  No huge rush.  I think I will go for a single supply.  I went my whole adult life without having a bench supply (I did have one in high school) and I doubt I'm going to do much which would require split supplies.

Almost everything in Amazon looks like, err, economically mass produced but perhaps slightly aesthetically lacking, but so does Circuit Specialists.

Thx.

DL
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: antonis on January 18, 2021, 03:10:32 PM
Quote from: Digital Larry on January 17, 2021, 02:15:58 PM
Well, except I think I could probably be OK with +/- 12 or 15 at 500 mA per side with adjustable current limiting and voltage/current metering.
Quote from: Digital Larry on January 18, 2021, 02:20:03 PM
I think I will go for a single supply.

I think you can easily build one.. :icon_wink:
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: iainpunk on January 18, 2021, 03:12:21 PM
if you want a cheap DIY option,
i have been using a laptop charger, providing 18v, filtering it with 10 ohm power resistors, and really big caps i had laying around,  and using a bd139 and 2n3055 driven by a simple potentiometer to regulate the voltage on the output, however, it can only source current, not sink, and its current is limited by those filtering resistors. (the pot has its own filter arrangements that isn't affected by the current draw)
i can draw the full circuit i used if you want.

cheers, Iain
Title: Re: Recommend a decent bench power supply for audio projects?
Post by: antonis on January 18, 2021, 03:29:39 PM
I've used circuit below in many variations with excellent results..

(https://i.imgur.com/25X2cRz.gif)

Also, old-time classic one..

(https://i.imgur.com/fNvxW9H.jpg)
You can delete R2, C2, R3, C3, D5, D6 & D7 negative charge pump respective items if you don't wish all the way down to 0V output..