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LJM Audio

What is the advantage of a regulated SMPS over non regulated? I'm afraid I don't know much about the technologies in each.

Regulated power supply provide constant voltage, regardless of the load.
Un-regulated power supply output voltage may vary, according to the current required by the load.

ClassD amplifiers have a relative lower PSRR (power supply rejection ratio) than traditional classA or AB amplifiers. They behave better with a regulated power supply.
 
L15D problem.

Hi,

I bought a pair of L15D on ebay.

I tried to power the boards as per the daigram on the sellers site.
I used a meanwell SMPS at 55 vdc and the amps did not power up.

I tied to PM ljm but his in box is full.
Can anyone help.

Best Regards,
elb
 
Hi,

I bought a pair of L15D on ebay.

I tried to power the boards as per the daigram on the sellers site.
I used a meanwell SMPS at 55 vdc and the amps did not power up.

I tied to PM ljm but his in box is full.
Can anyone help.

Best Regards,
elb

Hi Elb

I have L15D - it needs a slit rail supply with +/- rail and ground. Meanwell SMPS supplies only single rail only - are you using two Menawell supplies for +/- 55V DC?
 
Hi,

I bought a pair of L15D on ebay.

I tried to power the boards as per the daigram on the sellers site.
I used a meanwell SMPS at 55 vdc and the amps did not power up.

I tied to PM ljm but his in box is full.
Can anyone help.

Best Regards,
elb

Yes, you need dual voltage. + - 55V. You can see the power of your instructions.

If you have two identical single-voltage, and their ground and did not turn, you can get dual-voltage series.

Be careful on the power supply. :D
 
No Documentation

Took almost two months but I finally received the L7.
Only problem is that no documentation or schematic came with it. Tried to get a schematic but the only thing they sent was one that looked like post #5 in this thread. That's a joke for a schematic,especially if you have a problem and need to repair it.
This is the first kit I ever ordered that didn't come with any documentation,just
a bag of parts. The pc board looked proffesional.not bad at all.
I purchased the L7 kit from a guy named zoe_tsang on Ebay.
Looks like ljm_ljm of this thread is the designer of the amp.
I'm not trying to rip off his design,which looks like a good design but nothing special. I just want the schematic for future reference or if I have a problem.
Maybe the Moderators should have put this thread in the Commercial section.
The main point of this missive is to include documentation in your kits.

sam
 
Took almost two months but I finally received the L7.
Only problem is that no documentation or schematic came with it. Tried to get a schematic but the only thing they sent was one that looked like post #5 in this thread. That's a joke for a schematic,especially if you have a problem and need to repair it.
This is the first kit I ever ordered that didn't come with any documentation,just
a bag of parts. The pc board looked proffesional.not bad at all.
I purchased the L7 kit from a guy named zoe_tsang on Ebay.
Looks like ljm_ljm of this thread is the designer of the amp.
I'm not trying to rip off his design,which looks like a good design but nothing special. I just want the schematic for future reference or if I have a problem.
Maybe the Moderators should have put this thread in the Commercial section.
The main point of this missive is to include documentation in your kits.

sam

It is a very simple AMP.PCB above the logo like this figure,
One look will understand.

It has many of the parts are dedicated, if the damage that is irreparable.
 

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