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

[the_hamster 2]

Even if build quality were equal, a March Hypex amp is more robustly built and tested than VTV Hypex amplifiers are. As long as the dealer is offering some warranty, would not hesitate to buy the March P502.

Hope this helps!

Thanks very much for comment...dealer has listed item as “CPO”, which gets a 45day warranty plus normal 14day no-questions-asked return policy. Also, according to item spec., it was built in mid-2019, so not sure if March’s current line of P502s have any notable upgrades...may throw him an email before taking any further action.
Cheers

 

[beren777]

There’s a March Audio P502 (used) up for sale on AudioGon for $675 plus $27 shipping. VTV comparable model (new) sells for $699 (no trigger) plus shipping (charge?). So, are readers here satisfied with current build quality of VTV Ncore amps that one would opt for a new unit from them vs the March (sold by a dealer - may have been a trade-in)?

I have a VTV 252 from early 2020 that has some of the "less than optimal" wiring traits. It's been fine. Someday I'll fix it up but it hasn't had any noticeable impact on quality and the unit has performed as expected.

 

[the_hamster 2]

Ultimately went with the Audiophonics LPA-S500NC amp @ €632 plus shipping to US. Wanted switchable RCA/XLR inputs and the Ncore 502 module. Good price for quality kit.
https://www.audiophonics.fr/en/powe...tereo-class-d-ncore-2x500w-4-ohm-p-15016.html

 

[Henry666]

Hello to all. I am new here and having some problems with an acquired nc252mp here in Germany. I have read through the numerous posts regarding the grounding of xlr and the use of xlr to rca cables. I believe I wired everything correctly and bought the monoprice xlr to rca cable recommended by several people. Unfortunately when I hook uo the amp to the preouts of my argon audio sa1 all I here is loud feedback/ground loop and no music. I have installed the ncore in a plastic case. Could that be the problem with grounding issues? Any suggestions, answers and or critique welcome. Thanks.

 

[George Boles]

Hi, All.

With the VTV nCore MP amps like this one, obviously the Trigger turns the amplifier from Standby to ON.

• But how do you get the amplifier from ON to Standby if there is no Button to do this? Is this by using a second Trigger pulse?
• Or once the VTV amplifier is ON, is the only way to depower it by using the switch on the back of the amplifier or just turning it off at the wall?

Sorry, but I have no idea how Trigger normally works, and I won't have access to the power switch on the back of the amplifier once it is in my stereo cabinet.

(And I'm a bit torn about making these things last as long as possible: turning on and off seems like a bad idea, overall, but I still will depower them completely when a big electrical storm comes past or when I go on holidays.)

Anyways, any help would be appreciated.

Cheers,
George.

 

[Chromatischism]

Turning off the triggering device will also turn off the amp.

 

[Silver1omo]

The trigger is as you mention for standby/on. If you want to turn it off, you need access to the back switch.

 

[Rick Sykora]

There are some Hypex manufacturers that offer front panel switches.. As with the trigger, they can be implemented to transition to/from standby or full power. My sources do not have triggers, so while I have implemented a standby switch on one, am usually using an external power strip to control my amps.

This is why it can be useful to have the more recent hypex modules and/or added circuitry for soft power handling.

 

[George Boles]

Thanks Rick, Chromatischism and Silver1Omo.

• Chromatischism, does turning off the Triggering device turn the Amplifier OFF or into STANDBY, the latter so that the Amp can respond to pre-amp trigger when it is turned on again?
• Silver1Omo, does the Trigger also turn the Amplifier from ON into STANDBY, or is that not a function on the VTV amplifier?

Next question:

• Is the Trigger a continuous +12V signal or a single +12V pulse?
• So therefore to turn the module from ON into STANDBY (when turning off the Pre-amplifier for example), is this done by Ceasing the +12V signal, or is it a second +12V pulse (or perhaps a -12V pulse)?

I would imagine that if the trigger must send a continuous 12V signal for the amps to stay on, that this might become unreliable as the contacts between Trigger Cable and the 3.5mm socket become old and corroded - like me.

I never thought that a single 12V cable could inspire so many questions1

Best regards and thanks again,
George.

 

[Silver1omo]

The hypex modules have a standby mode and need to have an enable signal to fully power on.
If the amp only has a single power button the enable is shorted.
So the trigger is usually a switched jack. Nothing connected keeps it shorted.
You connect something, that something must provide the signal (3 to 12v), and yes, to be on, it needs to receive the voltage continously.

 

[Chromatischism]

Chromatischism, does turning off the Triggering device turn the Amplifier OFF or into STANDBY, the latter so that the Amp can respond to pre-amp trigger when it is turned on again?

In the case of my Audiophonics amp there is a power on/off switch on the back in addition to the momentary button at the front (back switch is required to be ON for the front button to work). So long as you leave the rear switch on, the triggering device will turn the amp on and off in sync just like pushing the front button. You can effectively forget about the amp entirely and never touch it again.

I am unsure how the VTV amp works but I imagine it is the same.

Is the Trigger a continuous +12V signal or a single +12V pulse?

It is a single pulse at startup and shut down. You can get the devices out of sync if you pull the cord or power the amp down yourself.

 

[Gorgonzola]

Really stupid question. How do I remove the top? It appears the case is a single piece with the endcaps attached. I pulled the four rear screws which only allowed the rear off.

You must remove the front face plate by turning the amp over and removing two tiny hex screws at the bottom. Then you can remove the face plate and access the front screws that secure the top cover. (Be careful not to loose the tiny hex screws. )

 

[Dundas]

There are some Hypex manufacturers that offer front panel switches.. As with the trigger, they can be implemented to transition to/from standby or full power. My sources do not have triggers, so while I have implemented a standby switch on one, am usually using an external power strip to control my amps.

This is why it can be useful to have the more recent hypex modules and/or added circuitry for soft power handling.

Although Hypex have a Soft Start module on their SMPS Power Supply Page they say it is for toroidal transformer based power supplies and is not recommended for their new (non toroidal) designs.

 

[Rick Sykora]

Although Hypex have a Soft Start module on their SMPS Power Supply Page they say it is for toroidal transformer based power supplies and is not recommended for their new (non toroidal) designs.

Hypex does not market a trigger module, RCA inputs or many other value add parts either, but many provide nevertheless. Hypex sells to OEMs to address these needs so they don’t need to supply.

 

[Dundas]

Hypex does not market a trigger module, RCA inputs or many other value add parts either, but many provide nevertheless. Hypex sells to OEMs to address these needs so they don’t need to supply.

I am saying that a soft start module is not necessary for Hypex's current lineup.

 

[Rick Sykora]

I am saying that a soft start module is not necessary for Hypex's current lineup.

Personally, have no power-up complaints, but have read some that do.

I have had power down issues but is much improved with newer revisions.

 

[Dundas]

In the case of my Audiophonics amp there is a power on/off switch on the back in addition to the momentary button at the front (back switch is required to be ON for the front button to work). So long as you leave the rear switch on, the triggering device will turn the amp on and off in sync just like pushing the front button. You can effectively forget about the amp entirely and never touch it again.

I am unsure how the VTV amp works but I imagine it is the same.

It is a single pulse at startup and shut down. You can get the devices out of sync if you pull the cord or power the amp down yourself.

I suspect that the front switch is a push on/push off type that connects pin J6.9 (Power supply enable) to ground which is what the trigger relay does. Looking at the pictures VTV Hypex amplifiers without triggers have this connection made permanently so the amplifier is only controlled by the switch on the back and is never in Standby mode.

Buckeye do it a little differently. They have a 2nd switch on the back which makes the connection between J6.9 and ground changing the amplifier to On from Standby and bypassing the trigger relay.

The question I have about VTV's trigger system is the 12v trigger out. Again looking at pictures, the trigger module is connected to J6.3 (Standby 5V out), J9.4 (Ground) and J6.4 (Power supply enable) so where is the 12V trigger out coming from (is it just a parallel of the 12V in from the controlling device?) and what is the 5V standby used for? It could be that the relay is 5V and the 12V in is just providing a high signal to control the relay circuit.

If I have got anything wrong please correct me.

 

[George Boles]

Thanks to everybody. So much information about a switch!
Best regards,
GB

 

[Rick Sykora]

If you are having an issue with noises during power up or down with your Hypex amp, here is what I did to resolve:

https://www.audiosciencereview.com/...on-your-workbench-right-now.11155/post-755309

 

[robpbg]

Here's their NC502MP based amplifier with 2x500W at 4 ohms.
https://vtvamplifier.com/product/vtv-amplifier-stereo-hypex-nc502mp-ncore-amplifier-500wx2/

What is the gain on that?