DIY Purifi Amp builds

[cooldude]

Has anyone drilled their own chassis? How hard is to drill holes for xlr

 

[Count Arthur]

It's pretty easy with a step drill bit:

Ideally you want to use it with a pillar drill/drill press, but you can get adapters for power drills:

 

[drfous]

But wait! They've used an inline mains filter with Y-caps! (Or did they?)

The spun around the power supply. I was looking to do that to get some shielding but was too lazy to extend the wiring harness.

 

[Matias]

But wait! They've used an inline mains filter with Y-caps! (Or did they?)

Looks so.

 

[cooldude]

Looks so.

Can you explain what is y-caps?

 

[Deleted member 65]

It's pretty easy with a step drill bit:

View attachment 102672

Ideally you want to use it with a pillar drill/drill press, but you can get adapters for power drills:

View attachment 102675

Exactly, that’s how I did it ...https://www.audiosciencereview.com/forum/index.php?threads/diy-purifi-amp-builds.10478/post-579024

 

[maverickronin]

Can you explain what is y-caps?

Here you go.

X and Y ratings are about where a capacitor can be used and what the consequences would be if it failed.

 

[JayR]

I just built another 2 channel Purifi power amplifier with SMPS1K-PFC. Really thanks for Sami help to overcome some issue and success to complete this fantastic amplifier, hope sound much better than hypex power supply

Hi Casshan
That's a really neat and compact build you have the with a micro-audio psu. Is it a galaxy 288 case from modushop? Do you have a template you could kindly share?
Kind regards
J

 

[NTSOS]

Hi,

To order the Okto Research dac8 Stereo....they want to match the EVAL 1 amps RMS voltage.

- Custom output voltage

- Choose a custom output voltage that matches your amplifier. Available in range from 1 to 12V RMS. Please specify the requested value in your order note.

Is 9.6 Vrms the figure Okto wants? It's the only value I can find in the data sheet that has an RMS value within the correct range. Okto Output to EVAL 1 Input?

from EVAL1 Data Sheet:

Vin_1%THD - Differential input voltage - To get 1%THD @ RL= 4Ω, VP=±65V - 9.6 Vrms

I wish I would have taken electronics instead of machining?

Thanks.

John

 

[Aardappel]

It IS the Ghent case, but with VTV custom front panel. But wait! They've used an inline mains filter with Y-caps! (Or did they?)

Just out of curiosity - given that Bruno and others have indicated that IEC filtering (EMI/RFI) at the unit using Y-Capacitors is not a good idea: what would happen if you were to plug the EMI/RFI filtered unit into a powerboard that is surge/overload protected and also RMI/RFI filtered (using Y-Caps)? Bruno has mentioned that any filtering (with Y-Caps) is okay as long as it is away from the unit. Would this solve any potential issues or make things worse?

Also - a lot of premium DACs have EMI/RFI filters built in, wouldn't those interferences pass on to the poweramp through PIN1 XLR (or worse, through the audio signal on RCA)?

 

[phoenixdogfan]

Hi,

To order the Okto Research dac8 Stereo....they want to match the EVAL 1 amps RMS voltage.

- Custom output voltage

- Choose a custom output voltage that matches your amplifier. Available in range from 1 to 12V RMS. Please specify the requested value in your order note.

Is 9.6 Vrms the figure Okto wants? It's the only value I can find in the data sheet that has an RMS value within the correct range. Okto Output to EVAL 1 Input?

from EVAL1 Data Sheet:

Vin_1%THD - Differential input voltage - To get 1%THD @ RL= 4Ω, VP=±65V - 9.6 Vrms

I wish I would have taken electronics instead of machining?

Thanks.

John

I have already been in communication with Kim of Purifi and posed this very question. The 9,6 VRMS is accurate and Purifi's recommendation is to round up to 10 VRMS if you wish to bypass the buffer stage.

 

[phoenixdogfan]

I've finally been able to put the holidays behind me, and I've done some tests on the returned Hypex SMPS 1200A400. Basically what I've done this time is refrain from hooking it up to the Purifi Unit or putting it in the Ghent chasis.

Before doing any of that I've measured the DC voltage coming off the pins or J1 and J4. The way I've done that is to attatch the wiring harness I've gotten from Ghent, which have been checked by the crew at Purifi and verified correctly wired (I've also checked them for continuity), and attached them to J1 and J4 and measured the dc voltage as soon as I turn the power on which I can turn on and off with my Gosund switch.

The one thing I notice is the power starts at an initial voltage and then falls off rapidly to zero. Is this what I should be expecting? The voltages are as follows:

for J1

Connection tested =======Pin Nos.===== Hypex Specified Vdc Range=======Measured Initial Reading
VDR + to VDR -===========J1.1 to J1.4====== 15.6 Vdc===================13.3 Vdc
HV+ to HV-============J1.2 to J1.5======= 49-72 Vdc=================113.3 Vdc
VDR+ to GRD============J1.1 to J1.3=======15.6 Vdc ==================14.2 Vdc
HV+ to GRD============J1.2 to J1.3=======49-72 Vdc==================60.0 Vdc
VDR- to GRD============J1.4 to J1.6=======15.6 Vdc ===================16.1 Vdc
HV- to GRD============J1.5 to J1.6=======49-72 Vdc===================59.9 Vdc

The major concern is why the voltage falls off after the initial surge. Is this normal. The measured VDR voltage also seems a little low. Is this a normal variation? Hypex gave a unitary value of 15.6 so I'm wondering if this is normal. Finally, measuring across the HV+ and HV - pins yields a reading of 113 volts DC, again is this normal? Shouldn't it be around 60-65 volts?

On to the readings out of J4. Again these reading rapidly fell to zero after the unit was powered up.

Connection Tested====Pin Nos.========Hypex specified Vdc Range=======Measured Initial reading

VAUX+ to VAUX-=====J4.1 to J4.2=======17-25 Vdc==================32 Vdc
VAUX+ to GRD====== J4.1 to J4.3=======17-25 Vdc==================14.4 Vdc
VAUX- to GRD======J4.2 to J4.3=======17-25 Vdc==================15.0 Vdc
AMPEN to GRD======J4.6 to J4.3=======.8 Vdc ====================.25 Vdc
FATAL to GRD======J4.10 to J4.3=======3.3 Vdc===================3.19 Vdc

My concern with these J4 reading is that Vaux output seems low. I was under the impression, it was supposed to output 22 Vdc in unregulated mode. I did check the strapping on J7 and J8, and it is set for positions 2-3 for each. The 115v jumper was in place when these reading were made as well.

So are these normal reading, and should I connect the Purifi module?

 

[NTSOS]

I have already been in communication with Kim of Purifi and posed this very question. The 9,6 VRMS is accurate and Purifi's recommendation is to round up to 10 VRMS if you wish to bypass the buffer stage.

Hi pdf,

Ok, great......thank you so much!

John

 

[JimB]

I've finally been able to put the holidays behind me, and I've done some tests on the returned Hypex SMPS 1200A400. Basically what I've done this time is refrain from hooking it up to the Purifi Unit or putting it in the Ghent chasis.

Before doing any of that I've measured the DC voltage coming off the pins or J1 and J4. The way I've done that is to attatch the wiring harness I've gotten from Ghent, which have been checked by the crew at Purifi and verified correctly wired (I've also checked them for continuity), and attached them to J1 and J4 and measured the dc voltage as soon as I turn the power on which I can turn on and off with my Gosund switch.

The one thing I notice is the power starts at an initial voltage and then falls off rapidly to zero. Is this what I should be expecting? The voltages are as follows:

for J1

Connection tested =======Pin Nos.===== Hypex Specified Vdc Range=======Measured Initial Reading
VDR + to VDR -===========J1.1 to J1.4====== 15.6 Vdc===================13.3 Vdc
HV+ to HV-============J1.2 to J1.5======= 49-72 Vdc=================113.3 Vdc
VDR+ to GRD============J1.1 to J1.3=======15.6 Vdc ==================14.2 Vdc
HV+ to GRD============J1.2 to J1.3=======49-72 Vdc==================60.0 Vdc
VDR- to GRD============J1.4 to J1.6=======15.6 Vdc ===================16.1 Vdc
HV- to GRD============J1.5 to J1.6=======49-72 Vdc===================59.9 Vdc

The major concern is why the voltage falls off after the initial surge. Is this normal. The measured VDR voltage also seems a little low. Is this a normal variation? Hypex gave a unitary value of 15.6 so I'm wondering if this is normal. Finally, measuring across the HV+ and HV - pins yields a reading of 113 volts DC, again is this normal? Shouldn't it be around 60-65 volts?

On to the readings out of J4. Again these reading rapidly fell to zero after the unit was powered up.

Connection Tested====Pin Nos.========Hypex specified Vdc Range=======Measured Initial reading

VAUX+ to VAUX-=====J4.1 to J4.2=======17-25 Vdc==================32 Vdc
VAUX+ to GRD====== J4.1 to J4.3=======17-25 Vdc==================14.4 Vdc
VAUX- to GRD======J4.2 to J4.3=======17-25 Vdc==================15.0 Vdc
AMPEN to GRD======J4.6 to J4.3=======.8 Vdc ====================.25 Vdc
FATAL to GRD======J4.10 to J4.3=======3.3 Vdc===================3.19 Vdc

My concern with these J4 reading is that Vaux output seems low. I was under the impression, it was supposed to output 22 Vdc in unregulated mode. I did check the strapping on J7 and J8, and it is set for positions 2-3 for each. The 115v jumper was in place when these reading were made as well.

So are these normal reading, and should I connect the Purifi module?

Outputs are + and -, so measuring across them is 2x output.

Otherwise, it seems something is not right on the SMPS causing it to shut down. If you turn off the power and turn it back on in just 5 seconds, do you see the same brief output levels as you have listed? Or does it need to be off for >1 minute to get such turn-on output again? This might guide to whether the SMPS think there is either a standby signal, or an amp-error signal.

 

[phoenixdogfan]

Outputs are + and -, so measuring across them is 2x output.

Otherwise, it seems something is not right on the SMPS causing it to shut down. If you turn off the power and turn it back on in just 5 seconds, do you see the same brief output levels as you have listed? Or does it need to be off for >1 minute to get such turn-on output again? This might guide to whether the SMPS think there is either a standby signal, or an amp-error signal.

I can turn it off, and repeat and get the same values immediately. So, those values should not edge downward but should remain steady?

All I'm doing here is placing the probes of the meter in the plug body that would connect to the Purifi and plugging the other end into the SMPS. Doing that for safety's sake. Should get the same values as placing the probes on the pins on the SMPS. Also connected Ghent's LED at J5 with his cable, and it did not light up. Did all this before I connected anything to the Eval 1, so we can't blame Purifi or Ghent's case anymore. Think the SMPS is just defective, and whatever they've done has served only to fix the effect of the root cause, while not addressing what's causing the problem in the first place.

I'm at the point where I'm refusing to believe it's my fault. This is a matter of connecting four harnesses, and setting three jumpers to connect the two units have have them up and running electrically. I know it's not error proof, but after following directions carefully, and having parts of my work reviewed by Hypex and Purifi (harness wiring, and jumper settings), and sending the unit back twice, I don't know what else I'm supposed to do.

 

[phoenixdogfan]

I'm not having any luck with Hypex service. Much as I hate, hate, hate to do this, I am probably just going to order a new one, b/c I would undoubtedly waste as much money in overseas freight as it will cost to just buy another one.

At the point where I have all new harnesses, don't connect it to anything but those harnesses, and still can't get a constant voltage off its VDR, Vaux, or HV outputs, I'd have to say it's broken, and given that it's already gone back twice and not been fixed, I'd say for all practical purpose, it's broken beyond repair.

Very, very frustrating!

 

[wineds]

I'm not having any luck with Hypex service. Much as I hate, hate, hate to do this, I am probably just going to order a new one, b/c I would undoubtedly waste as much money in overseas freight as it will cost to just buy another one.

At the point where I have all new harnesses, don't connect it to anything, and still can't get a constant voltage off its VDR, Vaux, or HV outputs, I'd have to say it's broken, and given that it's already gone back twice and not been fixed, I'd say for all practical purpose, it's broken beyond repair.

Very, very frustrating!

AMPEN doesn't look right. It looks like the PS is going into standby mode. Need you to measure all these relative to GND and report back :

SMPS Stand-by
Amp Standby
DC-Error
Amp Enable

See page 7 of the Hypex PS datasheet for signal details.

https://www.audiosciencereview.com/forum/index.php?attachments/smps1200axx0_09xx-pdf.49157/

 

[JimB]

I'm not having any luck with Hypex service. Much as I hate, hate, hate to do this, I am probably just going to order a new one, b/c I would undoubtedly waste as much money in overseas freight as it will cost to just buy another one.

At the point where I have all new harnesses, don't connect it to anything, and still can't get a constant voltage off its VDR, Vaux, or HV outputs, I'd have to say it's broken, and given that it's already gone back twice and not been fixed, I'd say for all practical purpose, it's broken beyond repair.

Very, very frustrating!

It's acting as if it thinks it should be in standby. To be clear, it behaves the same way with no cables connected, right? Just AC mains in and the 115VAC jumper? If so, I'd ask Hypex how they test - how it differs from what you are doing right now.

 

[phoenixdogfan]

It's acting as if it thinks it should be in standby. To be clear, it behaves the same way with no cables connected, right? Just AC mains in and the 115VAC jumper? If so, I'd ask Hypex how they test - how it differs from what you are doing right now.

If I don't have the cables connected, I would need to measure directly off the pins, right? Why would it think it should be in standby, it's not being given any load except the load of the cables.

I don't have the mains power cable in the amp, and the mains ground is floating (not attached to anything). Could that have a bearing.

 

[JimB]

If I don't have the cables connected, I would need to measure directly off the pins, right? Why would it think it should be in standby, it's not being given any load except the load of the cables.

I don't have the mains power cable in the amp, and the mains ground is floating (not attached to anything). Could that have a bearing.

Yes - measure straight at the pins on the SMPS itself. I don't think not having a ground connection would not matter to operation. DO measure the other voltages noted by @wineds.