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Neurochrome HP-LOAD Review (Headphone Dummy Load)

tomchr

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Right. But I'm not catering to the hobbyist with the HP-LOAD. I'm catering to the manufacturers. Why? Because they value their time and would rather spend on a finished instrument with known performance than cobble something together themselves. The automation would also be of value to them.

I strongly doubt 90% of ASR members are DIYers. Maybe we can convince @amirm to conduct a survey. In the market analyses I've performed over the years, the vast, vast majority of folks interested in DIY come to me through DIY Audio. Folks who know me through ASR or any of the other audio-related fora show no significant interest in DIY. Marketing 101: Know your audience.

Tom
 

tomchr

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Fair. Let me add precision: I strongly doubt 90% of ASR members build and/or design electronic circuits.

Tom
 

jtwrace

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Fair. Let me add precision: I strongly doubt 90% of ASR members build and/or design electronic circuits.

Tom
Let me add {my audio} precision: I strongly doubt 90% of ASR members build and/or design electronic circuits {using an Audio Precision AP5xx or other high quality instrument}. :p
 

tomchr

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tomchr

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Let me add {my audio} precision: I strongly doubt 90% of ASR members build and/or design electronic circuits {using an Audio Precision AP5xx or other high quality instrument}. :p
Heh. I actually doubt much of the ASR membership is designers or builders. We'll see. You can respond to my survey linked to above. I'm willing to be proved wrong ... by data.

Tom
 

jtwrace

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... by data.

Tom
1627927645087.png
 
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amirm

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On the other hand if I had one on my bench it would take me a long time around before I sorted the cords and programing to make the TTL load switching work.
It is all done for you in AP. There are programmable I/O lines that you can either interactivity in the Bench mode, or in batch mode in sequence to change. Here is the UI in bench mode:

1627930408372.png


Just put a 1 in any of those ports and the corresponding signal on the AUX bus goes up. Put 0 and it will go down. It is that simple.

I actually bought a relay board and made this work with it. I was then going to integrate the relay board with a new dummy load but then Tom contacted me about this project and I stopped. My time has value and I had already spent good bit research boards to use, figure out how to make this work, etc.
 

tomchr

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And the cord is a plain serial cable. Digikey. $6.
Just make sure to get one that has all nine wires connected straight through.

Tom
 

DualTriode

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Tom,

Remember my definition of DIY;

"Having a soldering station and parts bins"

Not owning Precision test equipment
Not being a manufacture big or small
Not being a designer

It took years for me to afford my first O'scope.

Thanks DT
 

tomchr

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Understood. I worded my survey accordingly. Feel free to participate in it.

Tom
 

DualTriode

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Understood. I worded my survey accordingly. Feel free to participate in it.

Tom

Tom,
You did not ask if the ARS member owns a soldering station and parts bins or not.
That is the question to determine if you DIY or not at a 90% level.
DT

@amirm,
Last night I read through the APX500 AUX TTL chapters.

I do keep a notebook to track the tests and programing so that I can do it again in six months without having to sort it all out again.
DT
 
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tomchr

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Good lord. What are you honestly trying to get out of this conversation?

Tom
 

jtwrace

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Tom,
You did not ask if the ARS member owns a soldering station and parts bins or not.
That is the question to determine if you DIY or not at a 90% level.
DT

Good lord. What are you honestly trying to get out of this conversation?

Tom
Oh he's not joking? :eek:
 

groovybassist

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@tomchr I don’t think it’s worth spending any more energy responding to @DualTriode. You created a well engineered, well built lab instrument for the industry that will hopefully improve their ability to test/improve their designs. You didn’t post it here as an advertisement, @amirm chose to do a positive review to showcase your product. Enough said…
 
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tomchr

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Rev. 2.0 of the HP-LOAD is now in stock. Unlike the previous version, Rev. 2.0 features protection against over-voltage and reverse polarity on the power supply input. It also features a chassis ground connection. Unlike the previous version, HP-LOAD Rev. 2.0 now includes the following accessories:
  • 3.5 mm TRS to 4-pin XLR adapter
  • 4.4 mm Pentacon to 4-pin XLR adapter
  • 6.35 mm (¼") TRS to 4-pin XLR adapter
  • 9-pin to 4-pin XLR cable (1.0 m/3.3 ft, 250 pF) with gold plated connectors
  • 9-pin serial cable for APx-500 remote control (1.8 m/6 ft)
  • Power supply with US, EU, UK, and Australia plugs
It still handles 8 W per channel and up to 63 V RMS voltage swing.

You can buy your HP-LOAD here: https://neurochrome.com/products/headphone-dummy-load

Tom
 

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MC_RME

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In case someone wonders about the differently looking front plate of the HP load in the above linked video: The unit has a lot of extra space inside and is quite easy to modify. So I

- added a buck down converter at the rear DC input so it can be used with nearly everything, especially typical +12 V power supplies
- added a Li-Ion battery block inside so it runs many hours without any power supply connection
- the black field in the top shows the charge state of the battery when pressing a button on it
- and because of the internal battery the unit needed a nice looking hard power switch on the front (down left)

My experience with the AP remote was less stellar, but that is not caused by the HP Load. The AP software has some unexpected restrictions. For example when doing a THD+N sweep versus level you can not set a THD+N max value where the sweep would stop - for example 1%. You are into clipping then and don't want to see crazy lines going up. Multiple impedance sweeps that have the X axis in Watts are cumbersome to do (that's why you don't see them on ASR). Automation of this all quickly lets you do it manually again to get nice looking graphs.
 
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