DIY Purifi Amp builds

[starfly]

It is not normal to use this with an SMPS1200A400. It is certainly NOT necessary.

Ok, thanks. I'll probably just skip that then. What are the main specs I should look for in a power supply that will provide standby power, and allow use with a 12V trigger? I think @JimM had used a MeanWell IRM-30 power supply. Can I just get anything that's similar to that? I'd prefer a more open design than that MeanWell power supply, as I suspect it might run a bit cooler that way.

And if I want to have two 12V trigger inputs, can I just splice the wires for each together and have them both enter the same power supply?

Also for the IEC socket that connects to the mains, what fuse rating is recommended?

 

[Matias]

I sent an e-mail to Modushop asking if they would customize the back plate for the necessary holes of the EVAL1 kit, and sent them the link to this thread.

Would the EVAL1 kit + Purifi amp modules + SMPS1200A400 + IEC with on/off switch fit into this case below?

Galaxy Maggiorato GX288 230 x 280 mm 10mm front panel BLACK

Width: body 230mm, inner useful 210mm
Height: 80mm
Depth: 280mm
Weight: 2,0 KG

49.50€

https://modushop.biz/site/index.php?route=product/product&path=25_291_293&product_id=444

 

[phoenixdogfan]

I sent an e-mail to Modushop asking if they would customize the back plate for the necessary holes of the EVAL1 kit, and sent them the link to this thread.

Would the EVAL1 kit + Purifi amp modules + SMPS1200A400 + IEC with on/off switch fit into this case below?



View attachment 65039

Galaxy Maggiorato GX288 230 x 280 mm 10mm front panel BLACK

Width: body 230mm, inner useful 210mm
Height: 80mm
Depth: 280mm
Weight: 2,0 KG

49.50€

https://modushop.biz/site/index.php?route=product/product&path=25_291_293&product_id=444

The depth looks too shallow to me. My Ghent case is 315 mm deep and it's a tight fit. May and be if you're going to drill your own holes in the back and bring the edge of the Eval 1 so it's flush with the back panel it might work, but even so I think it would be tight if it fits at all.

 

[JimB]

ABSOLUTE MINIMUM inside depth to fit an EVAL1 and an SMPS1200A400 is 250 mm.

 

[TimoJ]

Would the EVAL1 kit + Purifi amp modules + SMPS1200A400 + IEC with on/off switch fit into this case below?
Galaxy Maggiorato GX288 230 x 280 mm 10mm front panel BLACK

Yes it would fit. I'm using that case. Two pictures here: https://www.audiosciencereview.com/forum/index.php?posts/385389/

 

[Matias]

Yes it would fit. I'm using that case. Two pictures here: https://www.audiosciencereview.com/forum/index.php?posts/385389/

Thanks a lot for the confirmation. My build would be very similar to yours, but I would keep the banana connectors and use a IEC connector with fuse holder and on/off switch. Should be basic and easy as possible for a first time DIYer like me.

 

[TimoJ]

Thanks a lot for the confirmation. My build would be very similar to yours, but I would keep the banana connectors and use a IEC connector with fuse holder and on/off switch. Should be basic and easy as possible for a first time DIYer like me.

Yes, should be pretty easy job once you get all the holes drilled and lined up. Are you going to take the fully slotted/ventilated top cover option? I only have the regular one and have installed panels so that the ventilation slots on the bottom are near the back and on the top are near the front i.e. just over the PSU.

I'm going to soon order their GX388 model for a multichannel amp I'm building with Icepower 50ASX2 modules.

 

[Matias]

Yes, should be pretty easy job once you get all the holes drilled and lined up. Are you going to take the fully slotted/ventilated top cover option? I only have the regular one and have installed panels so that the ventilation slots on the bottom are near the back and on the top are near the front i.e. just over the PSU.

I'm going to soon order their GX388 model for a multichannel amp I'm building with Icepower 50ASX2 modules.

I am not 100% sure I will move forward with this project. But if I were, I would use the regular top cover. IMO the whole heating thing is way overrated as this module is highly efficient. I am not going to test it running flat out on resistors for hours or something. Real world music listening, even long time on high volume, was shown that it barely gets warm (as per barrows post).

 

[starfly]

Looking at the SMPS3KA400 power supply from Hypex, it mentions the following:

The SMPS3K is intended to power our range of high power amplifier modules. As a result, this SMPS product
does not feature the 2-quadrant operation as most of our other SMPS products do. Therefore, they are unable
to handle large reverse currents generated by half-bridge amplifiers operated at low frequencies. For this
reason, it is not advisable to use this SMPS to power half bridge amplifiers like our UcD700 and UcD400
modules when used in the frequency range below 100Hz. A workaround for this could be using the
UcD700/UcD400 in bridge mode, or reversing phase for half of the modules

Anyone know what they mean exactly, reversing phase for half of the modules? I'm considering use this power supply for a 3ch amplifier, and well, half of the modules would be 1.5 modules. And then, what exactly do they mean by reversing phase? How would that be done on the Purifi module?

 

[3ll3d00d]

Anyone know what they mean exactly, reversing phase for half of the modules?

Swap the wires on both the input from the XLR and the output to the speakers so the resulting output retains the same polarity.

Hypex engineering comment that best results mean using an even number of modules but find it hard to say the extent to which supply pumping will be an issue. This is probably because, as I understand it, the extent to which reversing phase helps will depend on the extent to which the channels are amplifying correlated content. The only way to find out will be to try it but I don't believe they will cover failures in this scenario under warranty so it is a bit of a risky one.

 

[TimoJ]

Looking at the SMPS3KA400 power supply from Hypex, it mentions the following:
Anyone know what they mean exactly, reversing phase for half of the modules? I'm considering use this power supply for a 3ch amplifier, and well, half of the modules would be 1.5 modules. And then, what exactly do they mean by reversing phase? How would that be done on the Purifi module?

What about if you just put two power supplies SMPS1200A400 for L/R and SMPS600A400 for the center?

 

[SIY]

Try and listen ....
my ear finds it better and it correlates with the sinad score

OK, so no evidence. And no ears-only evaluation.

 

[SIY]

my ear confirms sinad that's all, i just suggest that he try to compare ... it costs nothing, just switches to move

If you don't level-match to better than 0.1dB and compare blind, your "ear" is not what's in play.

 

[PaulD]

I know ... i know your point of view...
But it don’t cost anything to try it .... and Sinad agrees with my ears

Yes it does cost something, it denies science and misleads people with potentially very false information. You can play those games with yourself, but presenting it as some sort of "result" when we all know it is not is just publishing BS... Far more likely is that you "hear" what your mind tells you the SINAD should "sound" like...

You are far better off not reporting it, or even better is participating and supporting a study that WILL give something worthwhile, like a level matched DB test.

 

[Wombat]

@Dbfr you are out of your depth, mate. Not uncommon on ASR, nowadays.

 

[Dbfr]

Yes it does cost something, it denies science and misleads people with potentially very false information. You can play those games with yourself, but presenting it as some sort of "result" when we all know it is not is just publishing BS... Far more likely is that you "hear" what your mind tells you the SINAD should "sound" like...

You are far better off not reporting it, or even better is participating and supporting a study that WILL give something worthwhile, like a level matched DB test.

keep in mind that what makes you're looking for the best is to give pleasure to your ears ...
I just suggest to someone who is not using the full potential of his DAC to do this test and so don't use the buffer stage and give us his feelings.
Yes it will a feeling and not a measured fact, but what makes us vibrate are our ears. The microphone and the oscilloscope are facts, but the ear is the judge of the final result, those that say whether one takes pleasure in listening or not.
It will remain a "feeling" I agree ...
i think i'm going to delete all my post and photos...

 

[Wombat]

keep in mind that what makes you're looking for the best is to give pleasure to your ears ...
I just suggest to someone who is not using the full potential of his DAC to do this test and so don't use the buffer stage and give us his feelings.
Yes it will a feeling and not a measured fact, but what makes us vibrate are our ears. The microphone and the oscilloscope are facts, but the ear is the judge of the final result, those that say whether one takes pleasure in listening or not.
It will remain a "feeling" I agree ...
i think i'm going to delete all my post and photos...

No need to do that.

 

[SIY]

...but the ear is the judge of the final result...

Which is why blind level-matched evaluation is essential. It's ears-only, no peeking. Very basic controls.

 

[starfly]

Swap the wires on both the input from the XLR and the output to the speakers so the resulting output retains the same polarity.

Hypex engineering comment that best results mean using an even number of modules but find it hard to say the extent to which supply pumping will be an issue. This is probably because, as I understand it, the extent to which reversing phase helps will depend on the extent to which the channels are amplifying correlated content. The only way to find out will be to try it but I don't believe they will cover failures in this scenario under warranty so it is a bit of a risky one.

Thanks. Not sure I want to take that risk. Purifi themselves told me that the smps1200 will likely be adequate for a 3ch setup, and if it lacks power it's better to add a smps600 or another smps1200.

They say 3 channels will be hard to balance with the smps3k, and perhaps the only way to do it well is to use the 3rd channel in btl (bridged, right?) mode. But that would mean getting two modules for 1 channel, which is overkill to me.

So I think I'll just stick to the smps1200 at this point, and when I add a 3rd channel just splice all the wiring, or get the smps600.

 

[Vincentponcet]

Looking at the SMPS3KA400 power supply from Hypex, it mentions the following:



Anyone know what they mean exactly, reversing phase for half of the modules? I'm considering use this power supply for a 3ch amplifier, and well, half of the modules would be 1.5 modules. And then, what exactly do they mean by reversing phase? How would that be done on the Purifi module?

They talk about UcD700/UcD400.
I read somewhere that Purifi amp is not subject to power supply pumping because the way they use power supply.