DIY Purifi Amp builds

[boXem]

From a technical perspective, using Hypex eval buffers is NOT the way to go.

 

[ctbarker32]

From a technical perspective, using Hypex eval buffers is NOT the way to go.

It would seem Amir would not agree with you: "Measured performance is just a bit worse than Purifi reference design as power increases beyond 25 watts or so. Not an audible difference but would be good to figure out where this is coming from. I can't detect any improvement from Sonic Imagery discrete 990enh opamps. So personally I would go with the stock gain stage and save enough money for a night out alone."
ASR Nord Purifi Review

 

[JimB]

It would seem Amir would not agree with you: "Measured performance is just a bit worse than Purifi reference design as power increases beyond 25 watts or so. Not an audible difference but would be good to figure out where this is coming from. I can't detect any improvement from Sonic Imagery discrete 990enh opamps. So personally I would go with the stock gain stage and save enough money for a night out alone."
ASR Nord Purifi Review

I don’t think the input buffers in that review are the stock Hypex evaluation/development modules that @BoXem was referencing.

 

[JimB]

Thanks! So do I understand right that a normal person doesn't ever need to do some kind of SMD desoldering if they prefer SpeakON? Just 2x2 wires to solder and that's it?

Pretty much.

 

[Matias]

I don’t think the input buffers in that review are the stock Hypex evaluation/development modules that @BoXem was referencing.

Yes, Amir compared stock Purifi EVAL-1 buffer versus discrete opamps. VTV cheapest option is stock Hypex buffer. These are different.

 

[boXem]

It would seem Amir would not agree with you: "Measured performance is just a bit worse than Purifi reference design as power increases beyond 25 watts or so. Not an audible difference but would be good to figure out where this is coming from. I can't detect any improvement from Sonic Imagery discrete 990enh opamps. So personally I would go with the stock gain stage and save enough money for a night out alone."
ASR Nord Purifi Review

1. I don't see the relation between the review you mention and Hypex buffers
2. Amir doesn't test immunity to external disturbances, so he wouldn't anyhow detect the weakness of Hypex buffers that have been designed for evaluation only

 

[JimB]

I don’t think the input buffers in that review are the stock Hypex evaluation/development modules that @BoXem was referencing.

Regardless, even with a premium for better input buffering, the pricing is impressive.

 

[ctbarker32]

Yes, Amir compared stock Purifi EVAL-1 buffer versus discrete opamps. VTV cheapest option is stock Hypex buffer. These are differente.

I am currently happy with the "Hypex Factory Buffer" that VTV supplies. I have experience with opamp rolling using my Burson Lycan Headphone amp and have a dozen or more discrete and packaged opamps by many of the "hyped" brands. While an interesting exercise, I am not convinced going with a boutique opamp design will yield more "quality" over what I have now. For my first Purifi amp, I wanted to stay close to the default sound.

"The default buffer for the NCore and Purifi is the Hypex factory buffer. It offers 14db of gain and uses a very high quality IC opamp and delivers the famous Hypex “house sound.” VTV FAQs

The option is always open as I believe I can easily order replacement input buffer boards from VTV.

 

[AndrewDavis]

As I understand VTV offers a single buffer board (the Hypex demo board) with the option to upgrade the opamps.

I can't say what the Nord buffer boards are, they could also be "custom" Hypex boards re-branded for Nord, just like VTV does. Nor could be Nord's own design.

 

[NTK]

For reference, here is the schematic of buffer in the Hypex NC500 eval board.


Here is the Purifi eval board buffer. Notice the missing components in the Hypex eval board?

 

[boXem]

For reference, here is the schematic of buffer in the Hypex NC500 eval board.
View attachment 88912

Here is the Purifi eval board buffer. Notice the missing components in the Hypex eval board?
View attachment 88913

Where is the double like button?

 

[AndrewDavis]

Where is the double like button?

Press the like button twice.

 

[dwkdnvr]

It should be noted that you can buy the VTV Purifi Amp for 969 so if you're not married to the idea of the eval 1, you can get an assembled amp for less than the price of the components. Or even as a source of components for a diy project it might be a good deal.

Yeah, I'm still wondering whether getting the VTV amp and retro-fitting the neurochrome buffers might be the sweet-spot for return on effort. As long as you don't blow it up, of course.

 

[cooldude]

I would get the vtv to modify...but i already bought micro audio smps...so gotta stick to diy

 

[cooldude]

Thinking about designing a board for 12v trigger circuit thats floating around here..unless someone made those already

 

[zappa]

Hi,
What is the problem with the stock speaker connectors (the banana ones) of EVAL1 board ?
Why everyone wants to change them ?

 

[AndrewDavis]

Hi,
What is the problem with the stock speaker connectors (the banana ones) of EVAL1 board ?
Why everyone wants to change them ?

If you're asking about the last few pages, I didn't have a problem with the banana connectors. I was just confused...not necessarily an unusual thing for me.

 

[zappa]

Thanks Andrew for your reply.
No, my question was not specifically about the last 2 pages.
I have seen that "problem" since the beginning, and I'm wondering why ?

it's not solid enough ?​

it's too limiting the wire size ?​

... ?​

 

[hyperknot]

Can someone explain, if its only the Hypex buffer which is not recommended for general home use, or also the Purifi EVAL1 board as well?

If so, basically our choices are pre-built or Neurochrome?

 

[boXem]

Thanks Andrew for your reply.
No, my question was not specifically about the last 2 pages.
I have seen that "problem" since the beginning, and I'm wondering why ?

it's not solid enough ?​

it's too limiting the wire size ?​

... ?​

+
it's directly soldered on the board, so if used with locking bananas it allows a very good connection.
-
Spades, raw wire, ... can't be used.
It's kind of fugly, but this is purely subjective.