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

[March Audio]

Hello from France

State of the art require that the right connector is used !

In that case it should be FC-16P Connector with pitch 2.54mm


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And the connector used by March Audio on his P502

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Are you calling state of the art the use of a connector designed for ribbon cables with standard wires?
If it works for Alan, good for him, but that is clearly not the proper example of "the right tool for the right task".

Yes we use the correct connector. The miniature Mogami balanced cable is the correct size conductor to fit into the compression pins. There is no difference in terms of quality of cable termination to the connector between the balanced cable and ribbon cable.

This means a screened connection directly to the connector instead of ribbon cable or additional PCBs and connectors.

Zero issues with this on the hundreds of amps sold.

 

[boXem]

Yes we use the correct connector. The miniature Mogami balanced cable is the correct size conductor to fit into the compression pins

This means a screened connection directly to the connector instead of ribbon cable or additional PCBs and connectors.

Zero issues with this on the hundreds of amps sold.

In oposition to most of our members, I have used these connectors. So let me doubt that during assembly you never had one of the six wires wrongly placed in the sixteen teeth. This would not happen with a ribbon. To avoid this, you would have to make a custom tool.
Again,not saying it's not working, just that it's not meant to be used as you do.

 

[March Audio]

Are you calling state of the art the use of a connector designed for ribbon cables with standard wires?
If it works for Alan, good for him, but that is clearly not the proper example of "the right tool for the right task".

In oposition to most of our members, I have used these connectors. So let me doubt that during assembly you never had one of the six wires wrongly placed in the sixteen teeth. This would not happen with a ribbon. To avoid this, you would have to make a custom tool.
Again,not saying it's not working, just that it's not meant to be used as you do.

No, never a single problem. Why should there be if the conductors are aligned correctly during assembly? They are clamped in place prior to compressing the connector top.

They are also tested after assembly to confirm.

Correct sized cable correctly terminated into the correct connector.

 

[boXem]

No, never a problem. Why should there be if the canductorsxare aligned correctly during assembly.

They are also tested after assembly to confirm.

Properly aligning conductors is the issue. Seems you never got it. As I said before, good for you.

 

[boXem]

Correct sized cable correctly terminated into the correct connector.

Could you please stop editing your messages after people replied. It's kind of irritating.
No, you don't use the correct connector. Period.
It's working for you because you have low volume production and a bit of luck. Such a solution would be crucified at the first design review in any company producing in reasonable volumes with a minimum of QA.

 

[March Audio]

Could you please stop editing your messages after people replied. It's kind of irritating.
No, you don't use the correct connector. Period.
It's working for you because you have low volume production and a bit of luck. Such a solution would be crucified at the first design review in any company producing in reasonable volumes with a minimum of QA.

If there is something relevant to be added to a post I will do so.

It is the correct connector with correct sized cable correctly terminated.

Its working precisely because of that and the quality control checking and testing of the assembly. Hence not one single failure. There is no difference in the quality of that connection than with a ribbon cable.

There is no luck involved.

The termination of the conductors is completely sound and robust just as it would be with a ribbon. It doesnt have to be a ribbon cable to make the connection sound and robust. What is required is the correct sized conductor, insulation and correct alignment. The only benefit of the ribbon is it makes alignment easier - nothing else. So that doesnt mean it cant be/shouldnt be done and if done that it is inferior or problematic. Just 6 conductors terminated instead of 16.

It also doesnt require duct tape to be wedged around the (wrong) connector to keep it in place. It's a tight and secure fit that will not work loose in shipping.

So Im sorry Fred you are wrong. Please dont judge your own failed attempts you previously mentioned.

If you would like to make further comment start with explaining what problems would arise and the potential failure mechanism.

 

[TimoJ]

What is required is the correct sized conductor, insulation and correct alignment.

What about the ground/shield wire? From the earlier picture it looked like you used just heat shrink over it.

 

[March Audio]

What about the ground/shield wire? From the earlier picture it looked like you used just heat shrink over it.

No, that is also connected. 1mm hs, again correct size.

 

[TimoJ]

No, that is also connected.

Yes, I meant that the heat shrink insulated wire goes thru the connector pins, not using a similar insulation like the two wires. The heat shrink looks loose/not heated enough since it's much wider than the others.

 

[March Audio]

Yes, I meant that the heat shrink insulated wire goes thru the connector pins, not using a similar insulation like the two wires. The heat shrink looks loose/not heated enough since it's much wider than the others.

No its just flattened when trimmed/compressed.

 

[boXem]

If there is something relevant to be added to a post I will do so.

It is the correct connector with correct sized cable correctly terminated.

Its working precisely because of that and the quality control checking and testing of the assembly. Hence not one single failure. There is no difference in the quality of that connection than with a ribbon cable.

There is no luck involved.

The termination of the conductors is completely sound and robust just as it would be with a ribbon. It doesnt have to be a ribbon cable to make the connection sound and robust. What is required is the correct sized conductor, insulation and correct alignment. The only benefit of the ribbon is it makes alignment easier - nothing else. So that doesnt mean it cant be/shouldnt be done and if done that it is inferior or problematic. Just 6 conductors terminated instead of 16.

It also doesnt require duct tape to be wedged around the (wrong) connector to keep it in place.

So Im sorry Fred you are wrong. Please dont judge your own failed attempts you previously mentioned.

If you would like to make further comment start with explaining what problems would arise and the potential failure mechanism.

Editing a post for changing its content has to be highlighted, that's called netiquette.

For the rest, failure modes are obvious, misalignment and incorrect angle between conductor and teeth. The second, being visible on the picture posted above, stresses the conductor.
And no, I never tried your method. I see it failing at the first glance, no time to loose with it. I have designed products produced 6-7000 a day, let's call this experience.
Now I will stop here. We could have concluded the discussion a bit sooner. I personally have more important targets in life than being right on the internet.

 

[March Audio]

Editing a post for changing its content has to be highlighted, that's called netiquette.

For the rest, failure modes are obvious, misalignment and incorrect angle between conductor and teeth. The second, being visible on the picture posted above, stresses the conductor.
And no, I never tried your method. I see it failing at the first glance, no time to loose with it. I have designed products produced 6-7000 a day, let's call this experience.
Now I will stop here. We could have concluded the discussion a bit sooner. I personally have more important targets in life than being right on the internet.

None of that happens because the conductors are correctly aligned. The design of the connector ensures they are.

The top of the connector that compresses onto the lower half has guide grooves for each conductor which ensures they are aligned. There is no misalignment. These guides also clamp the cable entry into the connector so the connection itself will not get stressed by any external cable movement.

You would know this if you had ever had experience of assembling one of these connectors.

It doesn't stress the conductors in any way. The conductors are clamped as mentioned above and are flexible. They are stranded conductors. They are just bending slightly into the sleeve. They also have other bends on the way to the xlr socket, so unless you are going to say that cables can never be bent......

It doesn't matter how many products you have designed and produced, that doesn't make you correct or knowledgeable about this. You cite problems which don't exist and see it failing "at first glance". Yet proper examination shows it won't, a conclusion borne out by the real world usage.

So yes, let's stop there.

 

[rebbiputzmaker]

Editing a post for changing its content has to be highlighted, that's called netiquette.

For the rest, failure modes are obvious, misalignment and incorrect angle between conductor and teeth. The second, being visible on the picture posted above, stresses the conductor.
And no, I never tried your method. I see it failing at the first glance, no time to loose with it. I have designed products produced 6-7000 a day, let's call this experience.
Now I will stop here. We could have concluded the discussion a bit sooner. I personally have more important targets in life than being right on the internet.

You are actually correct that is not really the most elegant way to make that cable. Use of the ribbon makes the whole assembly stable when you crimp and lock the top the entire ribbon actually keeps it level and it does not cause any undue stress. The other solution also provides much more contact area for the cable being inserted in and crimped as opposed to being pierced with small pins. The only issue with the other cabling method is to shim the block slightly to stabilize and make it more secure within the connector. Not 100% necessary but a cautionary procedure.

Very true, there are much more important things than worrying about this but it is interesting.

 

[March Audio]

You are actually correct that is not really the most elegant way to make that cable. Use of the ribbon makes the whole assembly stable when you crimp and lock the top the entire ribbon actually keeps it level and it does not cause any undue stress. The other solution also provides much more contact area for the cable being inserted in and crimped as opposed to being pierced with small pins. The only issue with the other cabling method is to shim the block slightly to stabilize and make it more secure within the connector. Not 100% necessary but a cautionary procedure.

Very true, there are much more important things than worrying about this but it is interesting.

There is no stress for the reasons pointed out and the resistance is no lower with the other connector due to surface area. The contact design clamps tightly around the conductor and makes a good low resistance contact.

Without the tape the other connector is loose - that's precisely why he has to put tape on it to stop it falling out. That means the electrical connection will be subject to potential issues.

The tape may help to address those issues but it is hardly a consistent solution and will turn into a sticky mess over time. It would be better to use the correct, properly fitting connector.

 

[rebbiputzmaker]

There is no stress for the reasons pointed out and the resistance is no lower with the other connector due to surface area. The contact design clamps tightly around the conductor and makes a good low resistance contact.

Without the tape the other connector is loose - that's precisely why he has to put tape on it to stop it falling out. That means the electrical connection will be subject to potential issues.

The tape may help to address those issues but it is hardly a consistent solution and will turn into a sticky mess over time. It would be better to use the correct, properly fitting connector.

Yes there are two ways to look at it. Both solutions work, maybe it depends on one’s sensibilities. The other connector is not loose, the pins actually hold it tight but the tape allows a tighter friction fit within the block which just adds more security for shipping, and inevitable rough handling.

“Sticky mess” I think not, I don’t know what type of tape you have, but I don’t see allot of good tape with oozing adhesive in my travels.

Nobody is perfect, but maybe you should not be so harshly critical of other builders. Everybody is really trying to do the same thing, give listeners good products, and good value for their dollar. That’s all we want as listeners and I believe most honest manufacturers like yourself, vtv and others also desire.

P.S. I see you are running a May sale. Shouldn’t it have been a March sale?

 

[CDMC]

Nobody is perfect, but maybe you should not be so harshly critical of other builders. Everybody is really trying to do the same thing, give listeners good products, and good value for their dollar. That’s all we want as listeners and I believe most honest manufacturers like yourself, vtv and others also desire.

I think this sums it up very well. While these connections may have never made it out of engineering for a large company making tens or hundreds of thousands of units, expecting a small manufacture making dozens or hundreds of units to have a custom engineered part, while maintaining a low price is unrealistic. We will of course ignore that even large manufactures that spend a fortune on engineering and testing, still find out in the field that components don't always perform as intended, resulting in things like field fixes of "apply tape No XXXX around the connector prior to securing".

 

[rebbiputzmaker]

What happens when you label your amp fragile.

 

[boXem]

I think this sums it up very well. While these connections may have never made it out of engineering for a large company making tens or hundreds of thousands of units, expecting a small manufacture making dozens or hundreds of units to have a custom engineered part, while maintaining a low price is unrealistic. We will of course ignore that even large manufactures that spend a fortune on engineering and testing, still find out in the field that components don't always perform as intended, resulting in things like field fixes of "apply tape No XXXX around the connector prior to securing".

How did you come to the conclusion that a custom part would be needed for a perfect fit? It's an H-box connector, there are hundreds, if not thousands mating parts available on the market.
There are standard and non standard ways to use these connectors, the two we have seen here are non standard. Mine will probably be not standard either BTW, but I will not feel attacked if somebody notice it.

Your amplifier is a Ghent kit, with its defects and qualities. The design choices we see here are the ones from Ghent, at the exception of the tape added by VTV.

 

[March Audio]

Yes there are two ways to look at it. Both solutions work, maybe it depends on one’s sensibilities. The other connector is not loose, the pins actually hold it tight but the tape allows a tighter friction fit within the block which just adds more security for shipping, and inevitable rough handling.

“Sticky mess” I think not, I don’t know what type of tape you have, but I don’t see allot of good tape with oozing adhesive in my travels.

Nobody is perfect, but maybe you should not be so harshly critical of other builders. Everybody is really trying to do the same thing, give listeners good products, and good value for their dollar. That’s all we want as listeners and I believe most honest manufacturers like yourself, vtv and others also desire.

P.S. I see you are running a May sale. Shouldn’t it have been a March sale?

If the pins held it tight there would be no need for tape to stop it falling out. You are contradicting yourself.

An opinion was asked for so it was given.

Is it being unnecessarily critical to point out the safety issue (in the other thread), or the incorrect pin 1 wiring, or the polarity of the signal connector wiring being wrong, or the dodgy soldering?

Perhaps we have different sensibilities.

 

[March Audio]

I think this sums it up very well. While these connections may have never made it out of engineering for a large company making tens or hundreds of thousands of units, expecting a small manufacture making dozens or hundreds of units to have a custom engineered part, while maintaining a low price is unrealistic. We will of course ignore that even large manufactures that spend a fortune on engineering and testing, still find out in the field that components don't always perform as intended, resulting in things like field fixes of "apply tape No XXXX around the connector prior to securing".

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.