VTV Hypex Ncore NC252MP (It's all Amir's fault)

[CDMC]

There is nothing custom about it, cheap off the shelf readily available component. As a wider point custom components are quite economically feasible for small manufacturers so long as they have the relevant technical knowledge and manufacturing relationships. We design and manufacture bespoke components, the case, PCBs and circuits etc.

Its the economy of scale where small manufacturers lose big time.

So economically feasible, that here in the USA, the to the door price the price of one of your NC252 amps is almost double that of VTV ($975 shipped v. $499). While I am pretty sure your cost isn't double that of VTV, I am equally sure that it is significantly higher than VTV's. I and others are more than willing to live with the lesser case and non-perfect connector (that appears to have no actual detriment in real life), which are really the only two items separating your amps and VTVs now that VTV has corrected the pin 1 issue.

I assume that when you say that you manufacture bespoke PCB's and circuits, you are speaking about for non-amplifier products, as you have stated time and time again that you use the Hypex and Purifi designs as implemented by the two companies.

 

[March Audio]

So economically feasible, that here in the USA, the to the door price the price of one of your NC252 amps is almost double that of VTV ($975 shipped v. $499). While I am pretty sure your cost isn't double that of VTV, I am equally sure that it is significantly higher than VTV's. I and others are more than willing to live with the lesser case and non-perfect connector (that appears to have no actual detriment in real life), which are really the only two items separating your amps and VTVs now that VTV has corrected the pin 1 issue.

I assume that when you say that you manufacture bespoke PCB's and circuits, you are speaking about for non-amplifier products, as you have stated time and time again that you use the Hypex and Purifi designs as implemented by the two companies.

It's not just about component cost, there are other costs to running a business and of course all businesses need to make a profit. Knowing the costs (we have very low costs BTW) I wish him luck getting his business to survive on a non existent margin.

No its not just pin 1 issue, the multiple issues have all been discussed, then the obvious one of competence which allowed those issues to occur. At least yours does have the mains safety earth connected, but that only started after I pointed out the problem in the other thread. How many amps sold without? I consider that a serious problem.

As I mentioned before I don't actually see it as a competing product, we are appealing to a different customer base. Some want the cheapest, some want higher quality and correctly safely built.

Anyway, thats all I am going to say. The info is there for people to make their own decisions about.

Other products yes. But also the amplifiers. There is the signal input RF boards, buffer amps and the control boards in there. Plus due to my instrumentation background we occasionally do electronics design work and manufacturing in that area.

 

[beren777]

I bought one of these from VTV recently. I noticed a few changes internally. I'll try to post pictures later.

• IEC outlet module safety ground is connected to the chassis, but I can't tell if the case anodizing was removed, which if I understand correctly is needed?
• XLR Pin 1 for the right XLR is connected to Pin 1 for the left XLR, which is connected to the chassis safety ground.

I haven't pulled the H-Box connector yet to see whether XLR Pin 2 is hot or not, but it has a darker tape on it and not duct tape.

I received the product a few days before the guaranteed delivery date, which I appreciated.

General questions:

• Shouldn't Pin 1 from each XLR connector be connected separately to a ground point instead of in series? Does it make any practical difference?
• Shouldn't channel ground from the amp board go to a separate chassis ground, not to the XLR connector?
• One of my listening setups is the home theater with a Marantz 6013 AVR. I normally use Outlaw Audio M2200's as L/R/C amps via pre-out on the Marantz. If I replace the L/R amps with the VTV amp, I get a loud hum on the other speakers connected to the Marantz when the VTV amp is on. The hum doesn't happen with the Outlaw amps. It did happen with a Behringer A800 I tested previously, so it isn't specific to the VTV amp. What should I test for troubleshooting?

 

[Silver1omo]

I bought one of these from VTV recently. I noticed a few changes internally. I'll try to post pictures later.

• IEC outlet module safety ground is connected to the chassis, but I can't tell if the case anodizing was removed, which if I understand correctly is needed?
• XLR Pin 1 for the right XLR is connected to Pin 1 for the left XLR, which is connected to the chassis safety ground.

I haven't pulled the H-Box connector yet to see whether XLR Pin 2 is hot or not, but it has a darker tape on it and not duct tape.

I received the product a few days before the guaranteed delivery date, which I appreciated.

General questions:

• Shouldn't Pin 1 from each XLR connector be connected separately to a ground point instead of in series? Does it make any practical difference?
• Shouldn't channel ground from the amp board go to a separate chassis ground, not to the XLR connector?
• One of my listening setups is the home theater with a Marantz 6013 AVR. I normally use Outlaw Audio M2200's as L/R/C amps via pre-out on the Marantz. If I replace the L/R amps with the VTV amp, I get a loud hum on the other speakers connected to the Marantz when the VTV amp is on. The hum doesn't happen with the Outlaw amps. It did happen with a Behringer A800 I tested previously, so it isn't specific to the VTV amp. What should I test for troubleshooting?

For Pin 1 questions look at the NC400 datasheet:

You want Pin 1 grounded immediately to the chassis, no "long" cables and no "star grounding".
Then the shield of the cable should also be grounded, just not to the same spot.
From manufactures comments a XLR connector that digs directly into the chassis is the preferred solution, something like the Switchcraft PQG3FST112.
Otherwise you might want to run a short cable from Pin 1 to the screw that holds the connector to the chassis (I'm assuming the holes have bare metal) and the cable shield to a hole in the amp floor making sure you have bare metal.

All that should help with your hum problem.

 

[CDMC]

From manufactures comments a XLR connector that digs directly into the chassis is the preferred solution, something like the Switchcraft PQG3FST112.

All that should help with your hum problem.

I was having the worst time figuring out what connector would dig directly in the case. Thanks for providing the info on the Switchcraft.

 

[somebodyelse]

The Neutrik product guide xlr section starts with a part number guide, explaining how to tell from the part number whether there's a panel contact and whether it's internally connected to pin 1 or not. Further on, particularly with the B series chassis connectors, you can see pictures of the pointed contact at one of the mounting screws that makes this connection.

 

[Silver1omo]

The Neutrik product guide xlr section starts with a part number guide, explaining how to tell from the part number whether there's a panel contact and whether it's internally connected to pin 1 or not. Further on, particularly with the B series chassis connectors, you can see pictures of the pointed contact at one of the mounting screws that makes this connection.

https://www.neutrik.com/en/product/nc3fbh1
https://www.neutrik.com/en/product/nc3fah1

There you go.

Edit:
v1 might be easier to connect to.
https://www.neutrik.com/en/product/nc3fbv1
https://www.neutrik.com/en/product/nc3fav1

 

[somebodyelse]

That picture also demonstrates why it can be hard to tell from an internal photo of an amp whether or not it's doing the right thing with pin 1. From a high angle, which is often all you can get, the link from the screw hole contact to the pin 1 contact would be hidden by the plastic body.

 

[Matias]

That picture also demonstrates why it can be hard to tell from an internal photo of an amp whether or not it's doing the right thing with pin 1. From a high angle, which is often all you can get, the link from the screw hole contact to the pin 1 contact would be hidden by the plastic body.

Which is what Apollon once answered, it is hard to see, but their amps use these types of XLR connectors that have the pin1 connected to the chassis.

 

[Silver1omo]

Agree, hard to see, but if we look at the hypex white paper:
https://www.hypex.nl/img/upload/doc/an_wp/AN_Legacy_pin_1_problems.pdf

And the NC400 datasheet, pin 1 should not even be connected to anything else in the circuit.
"So pin 1 should recruited to safely conduct loop currents around the audio circuit instead of through it".

AES48 is behind a paywall and Rane note gives a 404.

 

[shal]

AES48 is behind a paywall and Rane note gives a 404.

A newer version is here :
https://www.ranecommercial.com/kb_article.php?article=2107

 

[Silver1omo]

"The method specified by AES48 is to use balanced lines and tie the cable shield to the metal chassis (right where it enters the chassis) at both ends of the cable."

So ideally pin 1 in the XLR is empty but still have continuity to the case. So it might be hard to see but easily tested with a cheap DMM.

 

[Speedskater]

That picture also demonstrates why it can be hard to tell from an internal photo of an amp whether or not it's doing the right thing with pin 1. From a high angle, which is often all you can get, the link from the screw hole contact to the pin 1 contact would be hidden by the plastic body.

No, but a John Windt "Hummer tester" (from 1995) will quickly give the answer.
a short description at Jensen schematics:
Build the “Hummer” to Find “Pin 1 Problems” in Equipment
https://www.jensen-transformers.com/wp-content/uploads/2014/08/as032.pdf

 

[somebodyelse]

No, but a John Windt "Hummer tester" (from 1995) will quickly give the answer.
a short description at Jensen schematics:
Build the “Hummer” to Find “Pin 1 Problems” in Equipment
https://www.jensen-transformers.com/wp-content/uploads/2014/08/as032.pdf

If we had access to the hardware we wouldn't be commenting based on a photo
It's a recommended reference for people trying to fix a hum problem though.

 

[CDMC]

https://www.neutrik.com/en/product/nc3fbh1
https://www.neutrik.com/en/product/nc3fah1
View attachment 68264
There you go.

Edit:
v1 might be easier to connect to.
https://www.neutrik.com/en/product/nc3fbv1
https://www.neutrik.com/en/product/nc3fav1

HELP?!!!! I ordered the Switchcraft PQG3FST112, which was listed as a solder connection, but is a PCB. In searching further, there appears to be no combination of Pin1 one with a prong to ground to the case and solder pot connections, from Switchcraft, Amphenol, or Neutrik.

I assume that I can solder wire directly to the PCB pins, but am utterly baffled as to how the Switchcraft is connected internally and they provide no helpful drawings or explanation I can find. It appears that on this Pin 1 is not connected to the shell or the grounding prong (a quick check with my multimeter shows no continuity between pin one and the grounding prong, pin 1 and the shell prong, or the shell plug and grounding plug). Am I supposed to solder jumper wires from pin 1 and the shell prongs to the prong that goes to the case?

I am thinking I should return and just get the Neutrik with PCB connectors.

 

[lostinbostom]

For the past couple of years I have used a Parasound Zamp .v3 for my desktop system and enjoyed it. While I have from time to time thought about upgrading it, its size and cool running have kept it in place. Then Amir had to go do his darn test of it. That was enough for me to start poking at new amps. For me it quickly came down to the Schiit Vidar or giving a Class D amp a try. The Vidar was ruled out as being just a bit too large and power hungry (I tend to forget to shut off my amp and the Vidar draws a fair amount of energy at idle). I then started looking at Class D and based on the reviews, Hypex Ncore rose to the top for in the reasonable price stereo camp.

After researching, it came down to four candidates, IOM, March Audio, Audiophonics, and VTV. VTV is an unknown, but popped up when I was searching for hypex amps on Hifishark. It is from Vacuum Tube Values which gets cases made with their logo and then assembles various Ncore Models. I was originally looking at a NC122 but it was $489 while the NC252MP was $499. Same size case, $10 more, twice the power, it was a no brainer.

The VTV showed up last week and I had to let it break in as it was brittle out of the box. Just kidding. I received the VTV this morning. I didn't pull it apart, but the case is nice looking and it appears well assembled. I pulled out my Parasound and replaced it with the VTV. I did have to do a cable swap which put me back $75 as Benchmark was the only company that I could find that wires their RCA to XLR cables according to Hypex's recommendation.

The VTV sounds good to me. I did not do a bunch of back and forth swapping, but it seems to be a bit clearer and relaxed. I am guessing that when turned up the Parasound may have clipped a bit on peaks, while this does not. It is apparent if I turn the VTV way up (louder than I ever listen), it has the ability to overdrive the speakers.

All in all, I would rate the VTV as a great value for a Ncore amplifier. For those wondering, my desktop setup is a Dell Precision workstation running either Roon or Jriver, a Schiit Modi Multibit, Schiit Saga (thanks to their closeout for $200), VTV amp, Totem Mite speakers and a Rythmik L12 sub.View attachment 62550View attachment 62551

Hey
Bought the VTV NC252 back in April very happy with unit. PreBox S2 Digital for a pre feeding Buchardt S300's .
Warren was very helpful in the purchase!

 

[AndrewDavis]

feeding Buchardt S300's .

How does it drive the Buchardt's compared to other amps you've tried? There was debate about Peak vs continuous power in the IOM thread.

And I have one of these arriving tomorrow to drive Focal Aria 906's.

 

[Chromatischism]

For a three hundred dollar premium over what VTV or Audiophonics are asking, yes.

I also got the impression, looking at VTV's photos on the eBay listing, that the wiring work was questionable. Apparently my instincts were not wrong. Audiophonics looks comparatively impeccable, although with a pretty substantial lead time.

To be honest, I was thinking about VTV and traded a few emails with him, but the construction simply looks way too messy. Right now, my preference is to buy one from Audiophonics, as the price including shipping (but free of VAT for a US buyer) is less and the pictures I have seen of the construction look far better.

Not necessarily. Because the pricing info on the Audiophonics site includes VAT that is not charged to US buyers, and there's no clear explanation about how much one would cost if delivered to a US address, I asked them about that last week, and the reply was:

View attachment 62913

That total of 436€ at today's exchange rate is US$473 for their NC252MP unit.

I purchased the above-mentioned NC252MP amplifier from Audiophonics (RCA version). It took roughly 2.5 weeks to initiate shipment (during COVID-19 and with product out of stock), then arriving in only 5 days to the Central U.S. from Floirac, France.

You are correct that the listed costs include VAT, so you will be surprised to pay less than advertised. The total cost, including foreign transaction fee and shipping, was $485.94. Not bad for what you're getting. I do prefer the slim case as it takes up less space. Connectors are high quality and the 12v trigger connected to my AVR means no extra buttons to turn my system on. Soft power on and off. It works perfectly but I have not popped the case open - I could if anyone is interested.

 

[emildev]

Im very interested on the inside please as Audiophonics solved the cabling issue with a daughter board

 

[Chromatischism]

Im very interested on the inside please as Audiophonics solved the cabling issue with a daughter board

When was this change made?