A-Power PSU (Mean Well), ok to use?

[8bitbubsy]

I've got an A-Power PSU from amigastore.eu, and it works great on my A1200, even with a TF1260 accelerator. It has a Mean Well RPT-60B PSU inside.
However, Jens at Individual Computers says that MeanWell is "known-bad" and that people should get rid of them. How come?

[Jope]

I don't want to put words in his mouth, so here's 45mins of him explaining his rationale.

[ Show youtube player ]

[Daedalus]

There are a few issues at play here. First is that not all Mean Well units are equal. There are counterfeit units available from less official sources that some people use for DIY projects and then wonder why they get poor results.

Then there are some models that aren't as ideal as others. For example, the RPT-60B is a nice, compact module but it doesn't have any adjustment on the 5V rail, meaning the PSU gives out 5.0V. By the time the resistance of the cable and the 30-year-old PSU connection take their toll, that voltage could have dropped to a point where the stability of the machine is compromised. Even original Commodore PSUs run at 5.1 or 5.2V to compensate for the cable losses. This effect will be more pronounced the more load is put on the PSU. Other modules like PT-65B have an output adjustment that allows the output to be set a little higher in order to compensate for the losses.

As well as the 5V adjustment, the ripple specification of some of these modules doesn't meet the Commodore specification. Again, looking at the RPT-60B, it specifies 80mV, whereas the Commodore spec is 50mV. And again, the PT-65 module is better in this regard as its specification is 50mV. Ripple isn't usually a big deal for most setups, indeed original Commodore PSUs I've checked rarely meet the specification either, probably due to their age. But when modern expansions run really tight to the various tolerances involved, they can be caught out by things like excess ripple and noise, and IComp's devices in particular tend to be sensitive in this regard.

Finally, IComp sell their own PSU solution, which is all very nice and sophisticated and goes beyond the original PSUs in terms of regulation, and that seems to be the only one they actually recommend.

So, bottom line is that "Mean Well" or any other PSU is an unknown quantity and may or may not meet the exacting demands of some IComp products depending on the features of the particular module used and other factors in the construction of the PSU, e.g. grounding, wire gauge used and so on.

[8bitbubsy]

I see. PT-65B won't fit inside the A-Power PSU case, unfortunately. And I don't feel like buying the overpriced PSU from IComp with its expensive DHL shipping either.

EDIT: I meant PT-65B, not RPT-65B (doesn't exist).

[Leon Besson]

I’m using a A-Power at the moment to power a A1200 with BPPC 060 with BVision card. Not seen any issues thus far.
I’m guessing these are no good for the RapidRoad USB Clockport adapters? Something to do with the 5Volt line blowing the Clockport on the RapidRoad?

[Solo Kazuki]

Originally Posted by 8bitbubsy

I see. The RPT-65 series won't fit inside the A-Power PSU case, unfortunately. And I don't feel like buying the overpriced PSU from IComp with its expensive DHL shipping either.

Yes, it fits but with some works on case. I have such MW RT-65B in this bigger power supply case.

[Daedalus]

It's worth noting that the letters at the start of the model number are significant: the PT-65B is quite different to the RT-65B - different sizes, different mechanical and electrical design, different specifications (including ripple), and there's no RPT-65B as far as I'm aware.

[8bitbubsy]

Originally Posted by Solo Kazuki

Yes, it fits but with some works on case. I have such MW RT-65B in this bigger power supply case.

You're saying "bigger power supply case", but the A-Power PSU (not an original Commodore PSU) is tiny:




Do you have any pictures of your A-Power PSU mod?

Originally Posted by Daedalus

It's worth noting that the letters at the start of the model number are significant: the PT-65B is quite different to the RT-65B - different sizes, different mechanical and electrical design, different specifications (including ripple), and there's no RPT-65B as far as I'm aware.

I see. I was thinking of PT-65B, which is not that much bigger than the RPT-60B:

RPT-60B: 10.1cm x 5.0cm x 2.9cm (LWH)
PT-65B: 12.7cm x 7.6cm x 4.2cm

Maybe it can just fit in the A-Power PSU case by removing two of the screw posts...

[aeberbach]

Originally Posted by 8bitbubsy

I've got an A-Power PSU from amigastore.eu, and it works great on my A1200, even with a TF1260 accelerator. It has a Mean Well RPT-60B PSU inside.
However, Jens at Individual Computers says that MeanWell is "known-bad" and that people should get rid of them. How come?

Jens is wrong if he made such a blanket statement but I'm not sure he would have, he knows what he is doing and makes good products. But he also sells a far more expensive power supply perhaps he would rather you buy that than a Mean Well. Just be sure to get one with voltage adjustment and make sure your Amiga sees 5V at the plug, not 3 metres away from the Amiga at the power supply. There's a good chance your cable has some resistance especially considering the cost of good 5-conductor cable and the temptation to use trailer cord.

[Lineof7s]

Originally Posted by aeberbach

Jens is wrong if he made such a blanket statement but I'm not sure he would have

Presented for information purposes:


https://forum.icomp.de/index.php?thr...rsion-e0-woes/


https://forum.icomp.de/index.php?thr...ision-aga-mk3/

These are just two examples. Whether he's right or wrong (there's some debate) this is one of the things Jens is known for. It's a thing.

[aeberbach]

OK to say a particular Mean Well is not suitable for a particular purpose I guess. But if they're all bad then they have fooled an awful lot of people!

[Lineof7s]

Absolutely. The "particular purpose" in this instance seems to be "powering an Amiga", which gets awkward if one runs into an issue with some iComp hardware. *shrug*

[Leon Besson]

Originally Posted by Lineof7s

Absolutely. The "particular purpose" in this instance seems to be "powering an Amiga", which gets awkward if one runs into an issue with some iComp hardware. *shrug*

It always been a thing with the Rapidroad Clockport USB adapters Icomp sell. Jens always tell you that it’s the PSU that causes them to die