[PURIFI] New Purifi with custom "made in Italy" buffer, pictures inside )

[daniboun]

Hi amigos,

Just got my new Purifi Amplifier, after all, it remains conventional. But it has a custom "made in Italy" Buffer.
The Buffer involves 3 Genuine OP Amps Muse 02 + 03 (one single and two dual, I will give a test with some OPA1656 that I have in stock)
The Buffer globally improve the headroom. The OP Amps U1 is the main one, the Op Amps U2 and U3 help to increase te output current and help to better drive the Purifi modules. (if needed, with a simple modification U2 and U3 can be bypassed).
The little SMPS unit you seen @the side is in charge of the Power On led. Strangely on my first version, I had a problem with the switch and the led ... so as not to "stress" the led, I added this isolated power supply .It may be exaggerated at first glance but in the end it works well)

Some pictures :

 

[Doodski]

All that fits very nicely in the box. Looks good. What is the power output rating?

 

[daniboun]

Some spec :

Purifi 1ET400A module x2
Hypex SMPS1200A400 PSU
Custom Buffer made in Italy (one OP amp Muse 03 + two Muse 02)
H2000 full alu case made in Italy (GX serie)
Big Aluminium plate for better heat dissipation
Neutrik XLR connectors (Buffer can drive both RCA + XLR)
Isolated PSU for Power Led
Good quality RMI/RFI filter
Weight : about 5kg

8Ω 227W
4Ω : 425W
2Ω : 450W
Idle noise : A-weighted 11.5 µV
Default gain : 2.2X
Input Impedance : 47kohms
Output Impedance : 68 ohms

THD+N 5W , 1Khz 0.0006
THD+N 100W 20-20Khz 0.00017
THD+N 10W 20-20Khz 0.00029
Sinad 5W / 4R : 108
SNR : 131DB (ASR shows 128DB If I am not wrong)

 

[Doodski]

Great linearity from 8 to 4 Ohms. More than enough to hit the woofer stops.

 

[daniboun]

My main idea is to propose this model for a group buy @ very competitive price for European users only )

 

[Doodski]

Do the various PCBs come with CE approval or UL or CSA?

 

[daniboun]

I would say yes ) The Amplifier is fully assembled and some parts are made in Italy @ 100% (220V version only for European users)
If you look at the back of the case, all necessary safety precautions have been taken.


Keep in mind that I am not a professional just an enthusiast))))))))

 

[Doodski]

There are multiple builders around the planet offering quality class D amps like you are doing. There is no CE, CAS or UL certificates on them. I'm surprised some important person somewhere has not opened a file on this and tried to shut it down. I'm all for electronic kits, assembling and offering them but it's something to keep in mind.

 

[daniboun]

Thanks for the feedback )

 

[Doodski]

When I was repairing mechatronics some people would want me to modify their amps, electronics or whatever or bypass a blown thermal fuse in a transformer so the unit would work. Because of the legal parameters of those circumstances I would perform the operation for, "Test purposes." The customer was responsible for whatever they did after that. It's a good disclaimer. It's good to have such a arrow in the quiver per se.

 

[daniboun]

I take care of your advice, they are useful.

 

[boXem]

Why did you leave pins 17-18-19-20 floating?

 

[Vini darko]

Nice build its all very neat. Output impedance of 68ohms is a concern , that's going to affect speaker preformance surly?

 

[Matias]

Mind sharing some measurements, like power x THD+N in 8 and 4 ohms?

 

[abdo123]

I would take that CE certification with a grain of salt as it is a trust system and companies certify their own products.

It would be nice to send one to Amir for measuring.

 

[daniboun]

Why did you leave pins 17-18-19-20 floating?

That's a good question I might report to the developper of the Buffer. I will try to give the answer asap.

 

[daniboun]

I would take that CE certification with a grain of salt as it is a trust system and companies certify their own products.

It would be nice to send one to Amir for measuring.

Hi,
As explained, it's a DIY amp, I don't especially want to sell it in fact ... The idea of the "group buy" was rather to allow less fortunate people to have one Purifi at a good price .. but as I am an individual I do not think I will complete the process...
I've been living in France... so too complicated to ship it to Amir for an ASR test.

 

[Killingbeans]

Output Impedance : 68 ohms

Typo? µOhms?

 

[abdo123]

Hi,
As explained, it's a DIY amp, I don't especially want to sell it in fact ... The idea of the "group buy" was rather to allow less fortunate people to have one Purifi at a good price .. but as I am an individual I do not think I will complete the process...
I've been living in France... so too complicated to ship it to Amir for an ASR test.

I'm saying that for your own safety, as the Italian vendor will probably not pay you back if the amplifier exploded.

These certifications are important because even if there is 1 in million chance your house catches on fire that is one house too much.

 

[boXem]

That's a good question I might report to the developper of the Buffer. I will try to give the answer asap.

You can also ask him the noise level from the amp while you are at it. 11.5 uV A is for the module. (same for THD)