SMPS for a class A Jean Hiraga 30w

[nigelwright7557]

Question - could you put a second switched PSU after a standard SMPS PSU? Surely that is a resistive (mosfet)/inductive(transformer) load?

Depends on front end capacitors on 2nd SMPS.
They will stand a bit of extra capacitance but nothing big.
They start resetting with big caps stuck on them at least the ones I have used do.

 

[NickKUK]

Depends on front end capacitors on 2nd SMPS.
They will stand a bit of extra capacitance but nothing big.
They start resetting with big caps stuck on them at least the ones I have used do.

Yup that's my understanding too, I'm investigating using a LT3751 24V-200V capacitor charger (acts as a charger and regulated PSU) fed by a larger PSU. I'm expecting it would work because the input caps are relatively small (1000uF 24V vs a 24V 27A PSU). So the load seen is the current limited switching (resistance/inductance). The large 6,000uF (6mF) is sat on the other side of the second PSU - that then runs off to the amp.

 

[syklab]

I tried my Pass M2 (Class A 25w/ch +/- 24v rails and 1.25amp bias current) on a couple of 24v 5amp SMPS bricks designed for LED lighting. They were surprisingly quiet (much quieter than my linear supply) and easy to connect, plus lightweight, cheap, sounds great, and now I am not seeing any reason to go old school heavy iron/copper toroidal trafos anymore.

http://www.diyaudio.com/forums/power-supplies/306411-strange-forest-noise-linear-psu.html

Here is my FFT for 8v rms into 8ohms with the $17 bricks (x2):

This is what I used, looks like price went up to $19ea now:
https://www.amazon.com/SUPERNIGHT-100-240V-5-5x2-1mm-Converter-Adapter/dp/B00LUIKY4S/

How do you wire the two 24V 5amp SMPS to get +/- 24V?

 

[umut1001]

Hi.I am also building class a amplifier with +-24v and about 3a continuous current and looking for an smps with good price. But i do not know which can be better. I can buy 2pcs of Meanwell LRS-350-24 locally and make them serial for about 60usd.(i already have 2pcs of LRS24-150 but i am not sure it can be enough for continuous class a working and afraid it can heat a lot )
Or i can buy LLC smps from aliexpress. But do not know about their quality.Here alternatives.
https://tr.aliexpress.com/item/1005004119066712.html?spm=a2g0o.productlist.main.1.1194d1e41ssuAq&algo_pvid=e5b721f2-675e-4346-8f4f-333e00892051&algo_exp_id=e5b721f2-675e-4346-8f4f-333e00892051-0&pdp_npi=4@dis!USD!31.80!31.80!!!31.80!31.80!@210318ef17147666844593511e7f1f!12000028099505135!sea!TR!110065983!&curPageLogUid=1Dp2e20sylDp&utparam-url=scene:search|query_from:
or
https://tr.aliexpress.com/item/1005001407304522.html?spm=a2g0o.productlist.main.9.1194d1e41ssuAq&algo_pvid=e5b721f2-675e-4346-8f4f-333e00892051&algo_exp_id=e5b721f2-675e-4346-8f4f-333e00892051-4&pdp_npi=4@dis!USD!37.80!37.80!!!37.80!37.80!@210318ef17147666844593511e7f1f!12000015963850740!sea!TR!110065983!&curPageLogUid=dKoExCdgpvBD&utparam-url=scene:search|query_from:
or
https://tr.aliexpress.com/item/1005005708430372.html?spm=a2g0o.productlist.main.13.1194d1e41ssuAq&algo_pvid=e5b721f2-675e-4346-8f4f-333e00892051&algo_exp_id=e5b721f2-675e-4346-8f4f-333e00892051-6&pdp_npi=4@dis!USD!32.50!26.00!!!32.50!26.00!@210318ef17147666844593511e7f1f!12000034078277285!sea!TR!110065983!&curPageLogUid=2XgJtl1QE73U&utparam-url=scene:search|query_from:
or other which you can advise.
Best regards

 

[e_fortier]

How do you wire the two 24V 5amp SMPS to get +/- 24V?

From the Holly Grail Follower as example