If you’re selling a cure to a nonexistent problem and claiming unlikely sonic differences with no evidentiary support, the last word I would use is “honest.”
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DIY Purifi Amp builds
- Thread starter JimB
- Start date
Technically, you are right, when you are saying that there is no problem to be resolved by interchanging the OPAMPs; I’ve read about it. I am not debating that.
However, there is a problem that needs a solution. Some people are selecting audio equipment on subjective grounds, and they are very aware of that; many of them are even considering us, people that are paying attention to the concrete measurements, as geeks. I would even say that these subjective-criteria buyers are in the majority, and they are creating this special market demand/segment. One company or another would step to the occasion.
If you would have to sell amps to this market segment, how would you phrase the advertisement material on their behalf, so it would not be distasteful?
I have one of those, but I noticed that I get much better precision with a manual spike like the one in the picture. It has a very sharp tip.Or, an automatic one.
https://www.amazon.co.uk/JelBo-Auto...rds=center+punch&qid=1589829030&s=diy&sr=1-10
You’re making the common error of conflating “subjective” with “totally uncontrolled.” The actual problem is irrationality, and In my mind, exploiting that is not something I could do in good conscience.
phoenixdogfan
Major Contributor
3ll3d00d
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They just require a DXF file showing what you want. Details in https://modushop.biz/site/index.php?route=product/product&path=263&product_id=490
rebbiputzmaker
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Smh. There’s nothing wrong with what you linked to. If you don’t think there is a difference in sound between the opamps that’s your opinion, but offering them does not make someone a snake oil salesman. I read what you linked as being honest and straightforward nothing you link to is overhyped, or oversold.
The choices are functional components, as opposed to someone trying to sell the magic wooden block upgrade, todays special only $999.00!!!
No, it's a fact that opamps do NOT sound different when properly used and implemented. This is not an opinion. Implementations may sound different, but it is the implementation at fault and not the opamp. Every engineer knows this. There is an abundance of evidence to support this, such as:
https://nwavguy.blogspot.com/2011/08/op-amps-myths-facts.html
https://archimago.blogspot.com/2016/01/measurements-asus-xonar-essence-one-dsd.html
Saying that opamps sound different is just another hifi myth. Bet Scott Wurcer or SIY a bottle of Richebourg or La Tache that you can tell the difference in a properly conducted double blind test.
So the linked text is dishonest because the person behind the amplifiers knows that the opamps sound the same when properly implemented! The text is merely playing on the myth and fear of opamp rolling, it is not providing a properly engineered and argued solution to the problem. Worse, it is providing validity for the false idea that opamps sound different, misleading people.
Remember that everything that can be heard can be measured. We can measure well beyond the the limits of human perception. The specifications of the equipment fully characterises how it will sound.
maty
Major Contributor
Purifi 1ET400A / Hypex NC500 Input Buffer
https://neurochrome.com/products/purifi-1et400a-hypex-nc500-input-buffer?
[ This input buffer is intended for use with the Purifi 1ET400A and Hypex NC500 Class D amplifier modules.
Unlike other buffers, including the Purifi EVAL1 and the Hypex NC500 Evaluation Board, this Input Buffer will provide a differential output for the Class D amplifier, even if the input to the Buffer is single-ended. This ensures that even a single-ended source can drive the 1ET400A and NC500 to clipping, something the Purifi EVAL1, Hypex NC500 Evaluation Board, and many other input buffers cannot do. Many also report improvements in sound quality when the Purifi 1ET400A and Hypex NC500 are provided a differential input.
The buffer is a single-channel (mono) buffer, with the following features:
https://neurochrome.com/products/purifi-1et400a-hypex-nc500-input-buffer?
[ This input buffer is intended for use with the Purifi 1ET400A and Hypex NC500 Class D amplifier modules.
Unlike other buffers, including the Purifi EVAL1 and the Hypex NC500 Evaluation Board, this Input Buffer will provide a differential output for the Class D amplifier, even if the input to the Buffer is single-ended. This ensures that even a single-ended source can drive the 1ET400A and NC500 to clipping, something the Purifi EVAL1, Hypex NC500 Evaluation Board, and many other input buffers cannot do. Many also report improvements in sound quality when the Purifi 1ET400A and Hypex NC500 are provided a differential input.
The buffer is a single-channel (mono) buffer, with the following features:
- Differential (balanced, XLR) input, which can easily be configured for single-ended (unbalanced, RCA) operation as well.
- True differential output with common-mode feedback, which ensures a differential output, even when used with a single-ended source.
- Jumper-selectable gain: 0 dB and 13.2 dB for a total amplifier gain of 12.8 dB and 26.0 dB, respectively, when used with the Purifi 1ET400A.
- Gain can be further customized by adding a resistor (1206 size SMD and leaded/PTH supported).
- Plug-and-play connection with Hypex SMPS1200 and future Purifi power supply.
- Opamp power supply: Use the AUX supply provided by the SMPS1200, or add your own regulator. A small daughterboard with support for the Hypex HPR/HNR, LM7812/LM7912, and LM78L12/LM79L12 is available as a product option.
- Status indicator LED output (NC500: CLIP and READY; 1ET400A: READY).
- Speaker output is provided both on 6.3 × 0.81 mm quick-connect spades and a terminal block accepting up to AWG 10 (5.2 mm2) in size.
- The buffer can be disabled by removing two resistors. A three-pin connector footprint provides direct access to the Purifi 1ET400A / Hypex NC500 input.
- A two-pin connector footprint provides access to the remote sensing pins of the Purifi 1ET400A / Hypex NC500. ]
D
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”... even if the input to the Buffer is single-ended.”
Missed that part of the sentence ...
At least at a casual glance (all I've done, admittedly), it does.
Had an email exchange with Purifi, and they'll be releasing a mono input buffer next month with XLR/Speakon, XLR/Banana or no pre-installed sockets. No word yet on pricing.
Not sure yet if I should get the Neurochrome or go all Purifi.
Not sure yet if I should get the Neurochrome or go all Purifi.
Interesting, did they mention anything about the connection system to the power supply?
No, but they did share this CAD drawing:
They otherwise mentioned it uses the same buffer/gain stage, but a improved low noise regulator.
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What I like the most about the neurochrome offering is the 0dB buffered option.
What I would really like to see is an integrated DAC chip, with a 0dBFS output level matching sensitivity, and of course noise and distortion figures matching those of the amp...
Stereo buffer, USB and spdif inputs, ...
That would solve so many problems at once!
What I would really like to see is an integrated DAC chip, with a 0dBFS output level matching sensitivity, and of course noise and distortion figures matching those of the amp...
Stereo buffer, USB and spdif inputs, ...
That would solve so many problems at once!
OP
- Thread Starter
- #1,040
Interesting! I wonder why they would offer this. It is not required for amp module evaluation. Or is it? Does an (even) lower noise Vreg provide any amp output improvements? Otherwise, it is transitioning into a space they said they would not occupy - end user solutions. Anyway, I like it for odd-channel DIY builds (1, 3, 5). Price???
