Off the shelf SMPS to be used in a 100W guitar amplifier design

[iep]

I'm designing a compact but relatively high power guitar amplifier and am looking at power supply options. I could use a nice simple traditional linear supply with a big toroid but it's bulky and I think SMPS would be neater.

That said, I don't want to design my own SMPS for this project and so am looking at off the shelf solutions. There seem to be a few out there:

Connex High Efficiency Switched Mode Power Supply 300W / 72V. Trusted UK Seller. | eBay

or the cheaper:

500W +/-65V Amplifier Dual-Voltage PSU Audio AMP Switch Power Supply Board New | eBay

Has anyone used any of these or could recommend an alternative product? Ideally it'd have a +/-45V rail.

Cheers,

iep

 

[Enzo]

The 72v one appears to be a single supply, meaning you would need two of them, or design a single supply power amp with an output cap, like old Acoustic models.

 

[iep]

Hi Enzo,
Sorry, yes, that is the single ended variant but it is available in +/-45V too.

I'm just curious if anyone has used these or something like them for Audio. Having done a bit more digging, if I'm prepared to sacrifice power, I guess I could use a pair of Mean Well IRM 60 24s.

Cheers,

iep

 

[Kay Pirinha]

With ± 24V rails, you're sacrificing about 75% of output power, compared to ±45V rails.


Best regards!

 

[iep]

Absolutely but the IRM smps blocks are very appealing in terms of size and weight. I'd still be able to get ~30w out of the amp which might be enough. Only issue I've noted with them is the temp derating which might be a problem.

 

[iep]

As I say, happy to consider other approaches but finding a suitable SMPS module is challenging (at least for me).

 

[Kay Pirinha]

Here in Germany I've found and bought open frame SMPS modules of the same ratings as your Meanwells, but for only about € 5/ea. They can be series connected without any problems, thus giving ±48V rails, good enough for ~120W @ 8 ohms load.


Of course, for only 30W one pair would be sufficient.


Btw, do you know whether these Meanwells can be series connected without issues?


Best regards!

 

[iep]

They can be series connected yes, that's how I'd get the split rail. Do you have a link to any of these cheaper open frame examples?

 

[Kay Pirinha]

I can give the link to you later this day, as I don't have access to the website at the moment. Perhaps you might want to search by yourself at www.pollin.de.


Best regards!

 

[Kay Pirinha]

Well, here it is!

Best regards!

 

[iep]

Thanks! How are they selling them so cheap? Those can cost as much as £45 on some uk sites. Did you use them for an audio application?

 

[Nisbeth]

These are worth a look as well IMHO.Correct Link

/U.

 

[iep]

I've taken a punt on one of these. It gives me a nice ~45V rails plus a secondary output for my preamp output and came in at a reasonable price.

Connexelectronic

There are a few reports of these being used successfully with chipamps so I'll I'll report back once I've tried it out.

Cheers,

iep