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DIY Purifi Amp builds

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JimB

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Sure.
Just got a dual channel Proster PST095 off Amazon for cheap, hopefully it's "good enough" for this purpose. 2 Cutequeen resistors arrived as well to which, ironically, I'll be sure to attach some larger heat sinks. Should be ready to give it a try later this week or over the weekend. What voltage were your speaker outputs for the 98W so I don't have to do math?

Multimeter says these 8 ohm resistors are actually 8.3 ohms. Good enough?
28.03VAC on 8.05 ohms (cold). So, for you, equivalent power output would be ~28.47V.
 

maniolo

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Hello everybody,
I will try to be clear in my message, I am not very comfortable in English so I will let google take care of it ...

I found someone who makes purifi based amps near my house. He sent me pictures, it looks very clean. For AOP, he uses MUSES 02. 6 in total.
Suddenly I wanted to know if you already knew them and your opinion on these AOPs and if at any risk you had made comparative listening between them and those that I could see in the various assemblers, 1612, Sonic Imagery or Sparkos Labs ? I understood that the best but also the most expensive were the Sonics, but what about the Muses 02 that I can't see anywhere?
If I understood correctly, it is ultimately via the AOP that the sound of the purified changes, a bit like changing the tubes of an amp.

Excuse me if this kind of question has already been asked, I admit not having found an answer .... Thank you for your help!
 
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JimB

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Hello everybody,
I will try to be clear in my message, I am not very comfortable in English so I will let google take care of it ...

I found someone who makes purifi based amps near my house. He sent me pictures, it looks very clean. For AOP, he uses MUSES 02. 6 in total.
Suddenly I wanted to know if you already knew them and your opinion on these AOPs and if at any risk you had made comparative listening between them and those that I could see in the various assemblers, 1612, Sonic Imagery or Sparkos Labs ? I understood that the best but also the most expensive were the Sonics, but what about the Muses 02 that I can't see anywhere?
If I understood correctly, it is ultimately via the AOP that the sound of the purified changes, a bit like changing the tubes of an amp.

Excuse me if this kind of question has already been asked, I admit not having found an answer .... Thank you for your help!
Hello, @maniolo. This is a DIY topic, and not so much about the sonic benefits of various inputs. You might get better feedback in either of these two other places:
https://www.audiosciencereview.com/forum/index.php?threads/ultimate-1et400a-purifi-amplifier-sonic-shootout-€820-to-€8-344.14048/
https://www.audiosciencereview.com/forum/index.php?threads/purifi-1et400a-decisions-decisions.15739/
Also in later pages here:
https://www.audiosciencereview.com/...easurements-of-purifi-1et400a-amplifier.7984/
 
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OP
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JimB

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Hello everybody,
I will try to be clear in my message, I am not very comfortable in English so I will let google take care of it ...

I found someone who makes purifi based amps near my house. He sent me pictures, it looks very clean. For AOP, he uses MUSES 02. 6 in total.
Suddenly I wanted to know if you already knew them and your opinion on these AOPs and if at any risk you had made comparative listening between them and those that I could see in the various assemblers, 1612, Sonic Imagery or Sparkos Labs ? I understood that the best but also the most expensive were the Sonics, but what about the Muses 02 that I can't see anywhere?
If I understood correctly, it is ultimately via the AOP that the sound of the purified changes, a bit like changing the tubes of an amp.

Excuse me if this kind of question has already been asked, I admit not having found an answer .... Thank you for your help!
I can just add that asking about a device is not sufficient. It will also matter how the circuit is implemented, including circuit design, types and quality of other components, and layout, etc.. So, I don't think you can get useful feedback based on only the op-amp (unless it is widely known to be bad, or much more expensive than other comparable devices). Maybe you can try-out what your local source offers?
 

JaapDeventer

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Hi, I do have a question on grounding. The metal plate of the SMPS1200 does not make contact with smps ground.
The metal plates of the Purifi modules do have connection with ground.
The black coating of the Modushop case is quite resistant.
So without making a connection between the Purifi modules and the bare metal of the case somewhere the Purifi modules and the smps aren't connected to the ground of the case and mains ground at all. Could that be a problem?
 

Count Arthur

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You can remove some of the coating or anodising with some wet and dry sandpaper, or even a knife, where you want to make a good ground/earth connection.

Some cases come with patches that are already prepared:

1612105643246.png
 

JaapDeventer

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I asked my question about grounding because I have a little hum from my Purifi Eval1 amp. I did make blank spots at the screws of both the Purifi modules and the smps.

Because of the little hum I disassembled the amp today. I started wondering when I measured the smps seperately and it did not have ground connected to the metal plate.

While reassembling the amp I turned the smps around. Rewired the mains. But it hasn't helped. The amp still hums a little when I hold my ear just in front of a speaker.

Without anything connected its quiet. But as soon as I connect the Ares Il dac with xlr it starts humming.

Any tips?
 

TimoJ

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I asked my question about grounding because I have a little hum from my Purifi Eval1 amp. I did make blank spots at the screws of both the Purifi modules and the smps.

Because of the little hum I disassembled the amp today. I started wondering when I measured the smps seperately and it did not have ground connected to the metal plate.

While reassembling the amp I turned the smps around. Rewired the mains. But it hasn't helped. The amp still hums a little when I hold my ear just in front of a speaker.

Without anything connected its quiet. But as soon as I connect the Ares Il dac with xlr it starts humming.

Any tips?
Does it hum without power ground connected?
 

JaapDeventer

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Does it hum without power ground connected?
I've tried with the amp connected to mains without ground wire. I did this also for the dac. I don't know if I tried with both dac and amp ground disconnected from mains.
Sometimes it gets worse. Not better.
 
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JimB

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I asked my question about grounding because I have a little hum from my Purifi Eval1 amp. I did make blank spots at the screws of both the Purifi modules and the smps. ... Without anything connected its quiet. But as soon as I connect the Ares Il dac with xlr it starts humming. Any tips?
So, it's quiet with no input? Good. Either the hum is in the source, or it's to do with the connection.
 

JaapDeventer

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So, it's quiet with no input? Good. Either the hum is in the source, or it's to do with the connection.

Yes, totally silent with only speakers connected.
I suspect the xlr cables a little. I assembled them myself. The hum is clearly louder when the xlr cables are very close to the mains cable. It's the first time I'm using xlr so I don't know what to expect. I used the Canare cable below.
Screenshot_20210131-193458.png
 
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JimB

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Yes, totally silent with only speakers connected.
I suspect the xlr cables a little. I assembled them myself. The hum is clearly louder when the xlr cables are very close to the mains cable. It's the first time I'm using xlr so I don't know what to expect. I used the Canare cable below. View attachment 109677
Try a star-quad cable for analog mic applications, such as Canare L-4E6S. Many places offer good star-quad cables, including Ghent and Benchmark.
 

JaapDeventer

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The Canare DA206 is a twin core designed for digital signals, isn't it?

I'm very happy with the Mogami 2534 sarquad cables I got from Design Cable: https://www.designacable.com/studio...iophile-neutrik-balanced-xlr-to-xlr-lead.html

They also sell it, and other starquad cable, unterminated if you want to re-use your existing XLR connectors.

I did not really know what to buy as analog xlr cable. Did I buy the wrong cable or is starquad a more audiophile choice?
 

shawnbd

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Hello everyone,
Here I share my Purifi Eval2 design plan. Thanks to Kim from Purifi for getting the module Eval2 smoothly.
The Design studied the pictures that shared before.
The basic design is as follows

1. Use TPS7A4700 3300 to adjust the AUX voltage from SMPS 1200A400 to +-15.
2. SMPS1200A400 HV+- connects to 8000uf capacitors as power supply bus pumping, and plans to upgrade to 15000uf each module in the future.
3 Speaker protection uses the UPC1237HA chip.
4. The traditional SOFT START solutions.
5. Trigger module and switch parts is still in the design
The test connection is successful.

My Dac is SMSL M400 and my Speaker is Kef R3, It sounds similar to my previous ICE POWER 50ASX2SE , but it’s clearer and more straightforward more power。
 

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boXem

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Hello everyone,
Here I share my Purifi Eval2 design plan. Thanks to Kim from Purifi for getting the module Eval2 smoothly.
The Design studied the pictures that shared before.
The basic design is as follows

1. Use TPS7A4700 3300 to adjust the AUX voltage from SMPS 1200A400 to +-15.
Hello!
I guess this is not for Eval2 but for the other boards?
2. SMPS1200A400 HV+- connects to 8000uf capacitors as power supply bus pumping, and plans to upgrade to 15000uf each module in the future.
My understanding is that SMPS1200A400 is a 4 quadrant PS, thus not subjected to power supply pumping
3 Speaker protection uses the UPC1237HA chip.
This is already included in the 1ET400A
4. The traditional SOFT START solutions.
This is already included in the 1ET400A
5. Trigger module and switch parts is still in the design
The test connection is successful.

My Dac is SMSL M400 and my Speaker is Kef R3, It sounds similar to my previous ICE POWER 50ASX2SE , but it’s clearer and more straightforward more power。
Maybe simplifying your design by suppressing redundant functions a bit will allow a cleaner layout :).
 
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