• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

First One - mosFET amplifier module

Cresnet, I remember asking you about designing an SMPS for class A current but I was not aware you had succeeded:worship:
This quite impressive results you got.
Also, that is the first time I hear about an SMPS capable of handing that amount of extra capacitance.
USSA5 only requires about 1.5A per channel and uses square law effect of mosfet to maximize class A level.
Not sure I follow you when you say you have built a first sample yesterday but it has been tested on an M2X amp...:rolleyes:
I had problem with other SMPS in the past to perform proper amp grounding when there is only one ground terminal on the SMPS board. Is that the case for your SMPS?
Fab


Yes, it's all based on that discussion years ago, and the design was sleeping all that time, until a friend of mine who tested diffrent version on the M2X amplifier pushing me to continue.


I still have to test the SMPS on diffrent loads to see how safe to run it without FAN.

For the M2X test, it was made on diffrent SMPS, not this new version.
The diyAudio First Watt M2x
Post #3380

For the grounding issues, I don't know if you will face issues in grounding with this SMPS, as this SMPS has 3 GND points at the output.
It's impossible to know indeed, but in the M2X installation, all grounding issues vanished with basic ground loop breaker.

I will keep you posted once I am done testing this new SMPS, as I am too busy building
SMPS`s for Purifi.

Thanks
 
Re. Additional capacitance: would it be possible to have an RC filter after the smps and use much more capacitance in the C part (R being close to 0.1 Ohm)

I would be very interested for that set up after seeing also Soulution using this method together with Meanwell HRP-600 models and in some models they have close to 500.000 uF capacitance per rail.

Yes, you can use RC filter without issues, you can see that in the M2X setup.

I have fresh ELNA 10000uF audio capacitors, I will test the maximum number and will post the results here.

First test was with 35000uF extra per rail and no issues at all.

However, the SMPS will start up without 0.1R in series, 70000uF was directly connected at the output.

The SMPS has the below on board

1- Inrush current limiter
2-Turn on delay
3-Soft start circuit
4-Stand by SMPS


Will keep you updated
 
Hi Sami,

Could you post pictures of how the smps was connected with ground loop breaker?

Thanks
Do

Hi Dominic,

Attached is how the ground loop breaker was connected, this is exaclty what my friend sent me weeks ago.

Sam
 

Attachments

  • 7 at 12.53.40 PM.jpeg
    7 at 12.53.40 PM.jpeg
    40.6 KB · Views: 381
Hi Sami,

Could you post pictures of how the smps was connected with ground loop breaker?

Thanks
Do

Do you require to use some stand-off to be nylon instead of metal? I know for stand-off holes make connection to chassis.

Thanks
Do

If you are refering to one of my SMPS units, it will make diffrence only of you use one for the screw that connects the SMPS to the chassis, other stand-off are not connected to anything.

Sam
 
Yes, it's all based on that discussion years ago, and the design was sleeping all that time, until a friend of mine who tested diffrent version on the M2X amp....
.....
For the grounding issues, I don't know if you will face issues in grounding with this SMPS, as this SMPS has 3 GND points at the output.
It's impossible to know indeed, but in the M2X installation, all grounding issues vanished with basic ground loop breaker.

I will keep you posted once I am done testing this new SMPS, as I am too busy building
SMPS`s for Purifi.

Thanks
If this friends of yours is meanie than he is already an aficionado of the USSA5...;)
I think he has finally used a cap multiplier for the USSA5. I wonder how the cap multiplier would compare to your SMPS ...:rolleyes:
3 GND points should be ok:)
Thanks for keeping me posted:)
Fab
 
If this friends of yours is meanie than he is already an aficionado of the USSA5...;)
I think he has finally used a cap multiplier for the USSA5. I wonder how the cap multiplier would compare to your SMPS ...:rolleyes:
3 GND points should be ok:)
Thanks for keeping me posted:)
Fab

Yes, its him.


I think his next setup is the USSA5, not sure.

Allow me some time and I will post some results here.

I would like to point out that there will be a limited number of units available for sale, due to the huge delays in the arrival of raw materials, lead times, shipping delays etc..

9 Units are remaining as of 23-08-2020, once they are sold out there will be 90 days waiting.


Thanks
 
Hi Sami,

Just a quick question... you wrote this earlier

“...
SMPS output voltage in idle @ 230VAC = +-25VDC
SMPS loaded 6A output voltage is 45VDC
SMPS loaded 16A output voltage is 41VDC
...”

You say +/-25Vdc with 230Vac input but then just under your talking about 45V... did you mean 25Vdc under 6A and 21V under 16A?

Does the output noise increases a lot under say 7A compared to 2A?

Thanks
Do
 
Hi Sami,

Just a quick question... you wrote this earlier

“...
SMPS output voltage in idle @ 230VAC = +-25VDC
SMPS loaded 6A output voltage is 45VDC
SMPS loaded 16A output voltage is 41VDC
...”

You say +/-25Vdc with 230Vac input but then just under your talking about 45V... did you mean 25Vdc under 6A and 21V under 16A?

Does the output noise increases a lot under say 7A compared to 2A?

Thanks
Do

Yes, +-21V @16A
Ripple will increase, noise will not increase much.