DIY Purifi Amp builds

[sgoldwin]

This is Purifi's evaluation amplifier shared with reviewers. By the way, does anyone know what model of enclosure they used? It's quite interesting one.

it’s a custom case, nothing off the shelf. When I asked about it, Purifi mentioned also that it was quite expensive.
It’s certainly the best looking case of any of the DIY enclosures I’ve seen.

 

[phoenixdogfan]

Sorry to hear your problems here continue. It must be very frustrating. Just removing the face of S1 is no problem - mine ran fine after that, as did the one where I unsoldered it altogether. But there does need to be a working /AMPON signal on J3p1 of the EVAL1. And it must be in hardware control mode. The absence of VDR seems to be the top culprit at the moment. Why?

I suppose an active /FATAL from J3p3 of the EVAL1 to the SMPS could be an issue, as well.

Isn't hardware control mode the default mode? I did nothing AFIK to change the mode which would require resoldering, and I never touched the soldering iron to either the SMPS or the Eval 1.

 

[phoenixdogfan]

When I get the Hypex back I will first test with no back plate. Also plan to take it out and see if there's any traces that look like they could be contacting the back plate, though I don't think my case with the fabricated back plate fits together any differently from the new Ghent Purifi case.

Having taken the Purifi out of the case, I can see where the Eval 1 did indeed contact the back plate, in fact, I can see marks of the contact on the back plate. Further, I can see that some of those solder points practically go right to the very back of the board. I will take the board back to my fabricator and have them laser cut vent holes in the back board at those contact points.

So, I've sent the SMPS back to Hypex along with the wiring harnesses for aux and main power (which will enable me to see if they are at the root cause, which I doubt), I've also purchased Ghent's wiring kit, I'm sending the Eval 1 back to Purifi to have it checked and repaired if needed, and I'm going to have holes cut in the back of the chassis so there will be no contact whatsoever with the Purifi boards. If these measures don't fix it, anyone wanna buy a not working frankenamp for around $100?

 

[sloth_kwj]

View attachment 71118

And also.. they didn’t use their CAB1 cable kit.. It seems like SMPS1200 cable kit right?

 

[JimB]

Having taken the Purifi out of the case, I can see where the Eval 1 did indeed contact the back plate, in fact, I can see marks of the contact on the back plate. Further, I can see that some of those solder points practically go right to the very back of the board. I will take the board back to my fabricator and have them laser cut vent holes in the back board at those contact points.

So, I've sent the SMPS back to Hypex along with the wiring harnesses for aux and main power (which will enable me to see if they are at the root cause, which I doubt), I've also purchased Ghent's wiring kit, I'm sending the Eval 1 back to Purifi to have it checked and repaired if needed, and I'm going to have holes cut in the back of the chassis so there will be no contact whatsoever with the Purifi boards. If these measures don't fix it, anyone wanna buy a not working frankenamp for around $100?

Once you get back confirmed-good parts, just set them on a table and power them up long enough to see them 'work' with a voltmeter.

 

[JimB]

And also.. they didn’t use their CAB1 cable kit.. It seems like SMPS1200 cable kit right?

That cable set is just for their demo amps. It is not sold to anyone as far as I know.

 

[phoenixdogfan]

Once you get back confirmed-good parts, just set them on a table and power them up long enough to see them 'work' with a voltmeter.
View attachment 91732

Gonna do that too. Those LEDs on the Purifi look so pretty, I want to see them too.

 

[c2371]

@JimB what banana plug terminals are you using on your speaker cables?

 

[JimB]

@JimB what banana plug terminals are you using on your speaker cables?

I believe those particular ones were from PartsExpress in the US:
https://www.parts-express.com/angle...s-poly-shell-and-insulated-thumbscr--091-3608

 

[AndrewDavis]

Really silly question here. My Ghent case came without the screws for the inputs. These:

Ghent said the screw is a M3x8 self tapping. I don't think there will be a problem, but can anyone thinknif a reason why I can't use a M3 wood screw like this?

 

[JimB]

Really silly question here. My Ghent case came without the screws for the inputs. These:

Ghent said the screw is a M3x8 self tapping. I don't think there will be a problem, but can anyone thinknif a reason why I can't use a M3 wood screw like this?

They look good, and, likely, ARE good! Just check one for fit through the back panel and seating in the counter bore (though, it would really matter if that isn't perfect), AND that the 'body' of the screw will not split the plastic of the XLR.

Did Ghent mention why the screws were not included?

 

[beren777]

Really silly question here. My Ghent case came without the screws for the inputs.

This is what I ordered. Not sure if it's correct but they're in now. Watch out for Mouser shipping fees on small orders if you go that route. They have 74,000 of them right now if you need a bunch.

https://bit.ly/3eBcnyh

 

[AndrewDavis]

They look good, and, likely, ARE good! Just check one for fit through the back panel and seating in the counter bore (though, it would really matter if that isn't perfect), AND that the 'body' of the screw will not split the plastic of the XLR.

Did Ghent mention why the screws were not included?

Thank you for the tips! Ghent didn't say why. I bought the case just minutes after it was put up for sale, so I just assumed that it was one of those mistakes that happen with a new offering. I didn't want them to ship 4 screws halfway around the globe, so I just asked for a description and bought my own.

FWIW the customer service at Ghent Audio have been extremely helpful and friendly, both pre and post sale.

 

[JimB]

FYI, here is how Purifi wired their own demo box with dual outputs (on-board DELRONs plus 4-pole speakONs):

There are two wires for "black", from the two open holes in the FE02 board, connecting to the top and bottom tabs, . If you do this, solder from the top surface of the PCB - that's where the trace is. The same goes for leads to the side tabs from the "red" PCB holes. They used bare bus wire, but note the addition of red insulation to ensure no accidental output short on the wire that crosses behind the lower one from black to the left-hand tab. I'd solder the wires from the PCB first, before case assembly.

 

[JayR]

Hi All,
For the very first time in the known universe , Purifi amp powered by Micro-Audio SMPS with PFC function!
So many thanks to Sami for the help and for allowing me that world first I'm so glad with that build.
Now checking everything and finalizing layout, details. And then soon to play music!

Hi Luc
I was wondering if you could tell me what enclosure you used for your build?
My power supply from Sami arrives today!
Cheers
J

 

[ZestClub]

Which of the input Buffers/ Voltage Regulator combinations do you guys recommend as being the best sounding most analytical?

Sparkos Labs SS2590
Sonic Imagery 990 Pro OP Amp.
Weiss OP2-BA Opamp

 

[sloth_kwj]

Which of the input Buffers/ Voltage Regulator combinations do you guys recommend as being the best sounding most analytical?

Sparkos Labs SS2590
Sonic Imagery 990 Pro OP Amp.
Weiss OP2-BA Opamp

This community will recommend IC opamp because they opamp roll off. But Benchmark AHB2, Mola Mola use discrete opamp. I would recommand SI or Weiss but how about demo all of three or anything it is possible?

 

[maxxevv]

This community will recommend IC opamp because they opamp roll off.

Where in the world did you get that idea from ?

 

[boXem]

Which of the input Buffers/ Voltage Regulator combinations do you guys recommend as being the best sounding most analytical?

Sparkos Labs SS2590
Sonic Imagery 990 Pro OP Amp.
Weiss OP2-BA Opamp

Opa1612

This community will recommend IC opamp because they opamp roll off. But Benchmark AHB2, Mola Mola use discrete opamp. I would recommand SI or Weiss but how about demo all of three or anything it is possible?

IC opamps are the ones offering the best performance on the market.
Are you sure that ABH2 uses discrete opamps? That's not my understanding.
Concerning Mola-Mola, their discrete opamps are supposed to have a better performance than the IC ones, but they are not available on the market.
Last, but not least, the Purifi 1ET400A is full of IC opamps.

 

[sloth_kwj]

Where in the world did you get that idea from ?

In this forum and many other threads.

Opa1612

IC opamps are the ones offering the best performance on the market.
Are you sure that ABH2 uses discrete opamps? That's not my understanding.
Concerning Mola-Mola, their discrete opamps are supposed to have a better performance than the IC ones, but they are not available on the market.
Last, but not least, the Purifi 1ET400A is full of IC opamps.

Sorry, my mistake about AHB. They use AB+H in output stage. I know those op-amp are unavailable in market but I want to say not the all discrete is poor that much. btw it is sure that discrete have lots of disadvantages.