Hypex NC1200: Quality of the implementations

[tomchr]

Taking into consideration the differences in open loop gain, it suggests that the actual open loop distortion of the 1612 is about an order of magnitude lower than that of the NE5532, and about 2 when the additional GBW is taken into account.

That's probably not too far off. I know quite a bit went into lowering the distortion of the internal stages of the LME49720. I'd expect something similar to have been done on the OPA1611/12.

When comparing THD+N for opamps, always look at Rload. Many deliver excellent performance with Rload = 10 kΩ. Driving an open circuit is easy. Some are good at 2 kΩ. I seem to recall the OPA1611 being good down to 600 Ω as well.

Tom

 

[maty]

The choice of the cheap OPA1612 seems the most appropriate for both the Hypex NC500 and NC1200 modules and for the Purifi 1ET400A, as long as they have been well implemented. Hence the need to have measurements of custom buffers in the Hypex.

More than a week and Colin (Nord) remains unanswered. Now I send a second email and upload a screenshot.

 

[maty]

And to Apollon Audio too.

 

[wynpalmer]

That's probably not too far off. I know quite a bit went into lowering the distortion of the internal stages of the LME49720. I'd expect something similar to have been done on the OPA1611/12.

When comparing THD+N for opamps, always look at Rload. Many deliver excellent performance with Rload = 10 kΩ. Driving an open circuit is easy. Some are good at 2 kΩ. I seem to recall the OPA1611 being good down to 600 Ω as well.

Tom

Yes, you are correct, it does work at 600 ohms with, if I remember correctly, about a 3dB worsening in distortion relative to 2k ohms.
I chose to specify the comparison at 2k as this also was where the NE5532 was specified.

 

[maty]

DIY Hypex NC1200 with cheap chinese aluminum enclosure

https://www.avforums.com/threads/hy...lock-power-amplifiers-1200-watts-rms.2170755/

CASES

* Anodised Gold Effect Aluminium Slimline cases
* Large gold effect Aluminium Heatsinks on the outside
* 3 mm thick solid aluminium internal shielding between power supply and amplifier
* Acts as internal extra heat sinks
* Keeps separate runs for power cables away from speaker and signal cables
* Specially designed to have minimum cross talk and interference between cables
* i.e. lowest noise possible, you will hear things in the music you never heard before
* Far less energy consumption and far cooler than Class A and A/B
* Over 90% efficient
* No Krell badges


DIMENSIONS

* 336 mm wide
* 75 mm high
* 208 mm deep


From Germany, € 89 + € 10 = € 99 at EU home!

HiFi Aluminum Enclosure Class AB Power Amplifier Chassis Cabinet DIY Gehäuse Box

https://www.ebay.com/itm/163579182155

Sure there is a silver version!


BTW, you can see thick aluminum walls.

 

[Biblob]

thick

Sorry, I only trust it when walls are thick

 

[maty]

My criteria, with aluminum:

* if 4 mm or more -> thick

* only 3 mm -> thick

 

[Matias]

@maty amazing all the NC1200 implementations you could find. I didn't know there were so many.

 

[tomchr]

I'm sure Krell is thrilled that their logo is used by some Chinese chassis maker and eBay vendor.

Tom

 

[Xulonn]

I'm sure Krell is thrilled that their logo is used by some Chinese chassis maker and eBay vendor.

Tom

I can understand the problem with copying/counterfeiting current products (Rolex watches, designer bags), but I've often wondered how this compares with the legal issues of classic kit-cars replicas, because no one is fooled by a $25K Ford GT40 or classic Ferrari.

Then again, the generic Chinese amplifier case I posted in the VU meter thread would be great for one of your amp kits.

 

[tomchr]

I generally recommend the ModuShop chassis for my amps. The 2U Dissipante is perfect for a Modulus-86, 186, or 286. The 3U Dissipante is a good fit for a Modulus-686 running on ±28 V rails. To get the full 360 W out, you need ±36 V and the 4U tall Dissipante chassis.

www.modushop.biz available in the US through the DIY Audio Store (www.diyaudiostore.com).

Tom

 

[maty]

There are versions of box in silver and without any logo. For example, in some implementations of the modules designed by LJM.

https://www.ebay.com/itm/LJM-L12-2-...488897?hash=item1cb0b13981:g:45wAAOSw1NJbOOLL

Size: 360mm*270mm*80mm (W*D*H)

Surely they also sell it separately somewhere.

The striking thing about DIY is that it has sought to reinforce the thickness of the external walls and not just the internal division created on purpose.

 

[maty]

I have it clear. CNC design with 1 mm black coated steel case and 8 mm brushed aluminum front. Manager in a EU country like my gadget. ME = Maty Edition. With the holes (better small circles if it is possible and cheap) away from the audio circuitry.

 

[March Audio]

That's probably not too far off. I know quite a bit went into lowering the distortion of the internal stages of the LME49720. I'd expect something similar to have been done on the OPA1611/12.

When comparing THD+N for opamps, always look at Rload. Many deliver excellent performance with Rload = 10 kΩ. Driving an open circuit is easy. Some are good at 2 kΩ. I seem to recall the OPA1611 being good down to 600 Ω as well.

Tom

The 1612 is going to be difficult to beat. It's difficult to come to any other conclusion as to what to use if you have a blank canvass.

 

[JohnYang1997]

Nowadays opa1612 is considered cheap. I feel hurt. Middle priced maybe. Sure there are ic opamps that are a few times more expensive. Even the opa211 itself.
opa1612 is great but there are times when the circuit can be pushed further using other opamps. When used along opa1612 is really hard to beat.

 

[JohnYang1997]

BTW, one thing I don't understand is that lm4562 is almost half price of lme49720. I heard there are some protection circuit or biasing difference between the two. Idk if that's true or not.

 

[maty]

It is cheap vs the expensive "discrete" opamps. Sonic Imagery and Sparkos usually with Hypex modules

 

[kn0ppers]

I was going to say that. But I also don't think we should refer to OPA1612s as cheap, just because there is some boutique-expensive-discrete OpAmps out there.

The OPA1612 isn't cheap or expensive. It is a reasonably priced component, considering the performance and the market. They are definitely expensive enough to drive cost of manufacturing significantly if one decides to use them instead of cheaper alternatives.

I have no idea how all these companies (who make discretes) prosper, but looking at their prices, they have considered that and adjusted accordingly. I remember in PC forums everybody who owned an Asus STXII Soundcard (like I also do) was swapping OpAmps like crazy, hundreds of pages about opamps and their sonic properties. Some even removed the metal shroud, just to fit discrete OpAmps. Search for STXII Burson, how to make a triple slot PCIe card out of a mediocre single slot soundcard. Likely with very few measurable improvements.

 

[FrantzM]

It is cheap vs the expensive "discrete" opamps. Sonic Imagery and Sparkos usually with Hypex modules

Maty

English is a secondary language for me too. still ... the opposite of "expensive" is "inexpensive" cheap carries a connotation of inferior quality which is not the case for the opamps we are discussing about. These are "inexpensive", not cheap.

 

[kn0ppers]

They aren't even inexpensive They are still 4 USD per unit if you buy 10.000 at once. That is not inexpensive to me.

I can only repeat myself: I do not think boutique discrete opamps should be the reference when classifying other products. At least not for us here.