DIY progress report

Hi amigos,

I am in the process of assembling a new Pass A3 Amplifier. I come from Class D world....
I would like to avoid to use a Toroidal PSU for my modules, so question for experts :

Can I plug a SMPS Dual rail 28-0-28V VDC instead of the required Todoidal PSU 20-0-20 VAC for this module that already includes a rectifier ? (20 VAC = 28 VDC)

I guess I would only risk a Diod loss and nothing else ?


HTB1YazPjgfH8KJjy1zcq6ATzpXaZ.jpg
 
If you look up dual smps there are some triple output models with .+5, -24, +24.

Not high current but enough for any line level circuits.

Just smooth off the 50-12mv of ripple with a two or three stage CR network and you are done. Ideal for constant current dual supply loads. If you want better with regulation then consider the Silent Switcher.
 

OllBoll

Member
2010-11-22 11:24 pm
any recommendations for dual rail (+/-) SMPS . I don't think MeanWell make them, although 2 can be hooked up that way apparently....
Micro-Audio (Sami) makes excellent SMPS that have a topology where they don’t mind massive cap banks at the PSU output. Very low noise and designed for audio hobbyists ease of use or for OEM applications. I have used many of Sami’s supplies and they are excellent. They don’t have startup hiccup issues. Sami is also very customer service oriented. You are basically getting a custom PSU. You can specify exact voltage, what regulated auxiliary voltages you need (+12v, +5v always on and +/-15v switches are typical). The auxiliary outputs are linear regulated.

You can see he uses top quality name brand components. Here is an example that Vunce is using with a small Noctua fan to help keep it cool for continuous Class A operation.

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Here is my 30v 6A Class A PSU from Sami:
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Sami even provides for free, a blank cap bank PCB for you to load extra cap filtering after the SMPS.
 

wtnh

Member
2015-05-23 5:35 pm
I don't personally use SMPS's (so far), but from an engineering standpoint, I like the CONNEX approach which uses quasi-resonant switching. This greatly reduces noise and RFI. It was pioneered by Tektronix and used in their 7000 series mainframes. Obviously, in a high-end oscilloscope, low noise is a must-have. You can buy direct at https://connexelectronic.com/
 

nicoch58

Member
2004-10-06 12:20 pm
I don't personally use SMPS's (so far), but from an engineering standpoint, I like the CONNEX approach which uses quasi-resonant switching. This greatly reduces noise and RFI. It was pioneered by Tektronix and used in their 7000 series mainframes. Obviously, in a high-end oscilloscope, low noise is a must-have. You can buy direct at https://connexelectronic.com/
Half Bridge resonant
for a single V LLC Resonant topology plus Synchronous Rectification