Neutrik / Rean High-Current Jack NYS225

[Gone To Lunch]

Re Neutrik/Rean High Current Jack NYS225

Are they the same diameter as a standard Neutrik Jack, because I need to use a couple of them in one of those adaptors 2-into-1 Y-adaptors, because I am intending to connect the speaker output to an ART Split Mix 4 switch box with a single stereo input so I can hear the signal through different speakers?

[James Perrett]

The Splitmix4 isn't designed to work with speaker signals. (Unless you are talking about line level signal but then why would you want to use high current jacks with line levels?)

Speaker level signals should be connected directly point to point. Any switching or routing should be done before the power amplifier.

[ef37a]

I had not heard of those "high current" plugs so I looked them up and found a specification pdf.
This document tells you every mortal thing you could possibly want to know about the product EXCEPT the current rating!

That is academic anyway because the weak point in the connection is the jack itself, unless that has heavier contacts with greater contact forces the current rating of the 'system' will not be improved.

James, I agree that it is not a good idea to switch speaker signal levels and definitely not with something not designed to do so in a 'quality' audio setup. However, in the "ball of string and lump of chalk" world of guitar amplification speakers and amps are regularly switched using nothing better than 5 amp mains switches!

Dave.

[Gone To Lunch]

The Splitmix4 isn't designed to work with speaker signals. (Unless you are talking about line level signal but then why would you want to use high current jacks with line levels?)

Speaker level signals should be connected directly point to point. Any switching or routing should be done before the power amplifier.

Thanks very much for this!

I realise I need a dedicated speaker switch box, all of which have those spring clip connections for speaker cable. I think I will go for the QED SS40...

[ef37a]

The Splitmix4 isn't designed to work with speaker signals. (Unless you are talking about line level signal but then why would you want to use high current jacks with line levels?)

Speaker level signals should be connected directly point to point. Any switching or routing should be done before the power amplifier.

Thanks very much for this!

I realise I need a dedicated speaker switch box, all of which have those spring clip connections for speaker cable. I think I will go for the QED SS40...

I suppose it is just about acceptable if you want to switch in remote speakers in the kitchen or the bog but you should never put speakers in series in a high quality system. Once again, in the rough **** world of gitamps, done all the time!

Dave.

[Nazard]

If you want to go the DIY route, Hugh posted this very helpful piece:

https://www.soundonsound.com/sound-advi ... -power-amp

Incidentally, I think it's always a good idea to use connectors for their intended purpose, e.g. XLR low-level balanced, etc., as when you look at a connector you immediately visualise what it's doing and if it's performing a different function, that's when expensive mistakes can happen!

[Wonks]

The NYS225 plug has the same dimensions for the insertion part as other 1/4" jacks, so no compatibility issues there. What it is designed for is thicker wires, 12 AWG as opposed to 24 AWG for their standard jacks. So basically for fitting to speaker cable.

As ef37a says, there is no increased current handling capacity in the jack itself, it's all about being able to use thicker cable that's appropriate for speaker use. So you'll find these jacks fitted on speaker cables from lots of sources. I've got them on speaker cables I bought from Thomann. If mixed in with similar length signal cables, the larger jack body also shows at a glance that it's a speaker cable.

As speaker jacks sockets tend to be widely spaced, the extra width of the body isn't an issue there, but if used for signal cables, e.g. on the rear of an interface, you may find that the socket spacing is too narrow to fit multiple jacks of that type.

I would hazard a guess that the Pure Tone jack sockets with their double sets of contacts would handle more current than a standard jack socket, but it's not something I'd wish to try, and would much prefer to use Speakons.

[ef37a]

I am obliged Wonks for you mentioning Pure Tone Jacks. I had read of them in a post (here?) some months ago but this old brain had forgotten the name.

I have a Strat clone with a dodgy jack and intend to replace it but when I do I want to fit something better than bog standard but I could not remember the piggin'name!

I have seen the current carrying capacity of jack and their plugs debated in other forums in relation to guitar amps and cabs but I think people are being unduly concerned.
Probably worse case is a 100W amp into a 4 Ohm cab. That is about 5A rms and might be beyond the specification of many jacks. However 'music' signals are not the same as a 1kW kettle! The dynamic nature of the guitar amp signal means the connectors and cables are quite capable. You could probably get away with a 'curly git cable' on a speaker if you had to (but maybe 4R and 100W would be pushing one's luck!)

The bottom line is, "does your speaker plug at either end get hot or even a bit warm?" If not, KCACO if it does maybe look at Speakons!

Of course, beyond 100W and for serious quality high power systems better connectors make abundant sense.

Dave.

[sonics]

I realise I need a dedicated speaker switch box, all of which have those spring clip connections for speaker cable. I think I will go for the QED SS40...

What you really need is something like THIS.

Not cheap...

[ef37a]

I realise I need a dedicated speaker switch box, all of which have those spring clip connections for speaker cable. I think I will go for the QED SS40...

What you really need is something like THIS.

Not cheap...

Ooo! Nice! The book does not say so but I am sure that unit uses relays to effect the switching. Relays make the ideal speaker switches, they are very fast and provided the right contact material is chosen, they introduce no resistance or non-linearity into the circuit. They can also, as in that unit, easily be remote controlled together with logic to keep thing safe.

Dave.

[sonics]

Ooo! Nice! The book does not say so but I am sure that unit uses relays to effect the switching. Relays make the ideal speaker switches, they are very fast and provided the right contact material is chosen, they introduce no resistance or non-linearity into the circuit. They can also, as in that unit, easily be remote controlled together with logic to keep thing safe.

Yes, tasty Swiss engineering, eh?!

I do actually have a switcher for my monitors, but it's a lowly Wharfedale WPR-26. Still rated at 3000W, though!

[Gone To Lunch]

Thanks for your comments everyone.

The amp in question is a Thomann S-100 giving 65w into 8ohms, all three speaker pairs are 8ohms, and I found this QED MA33 switch box:

https://support.qed.co.uk/portal/api/kb ... nline=true

[Wonks]

I do actually have a switcher for my monitors, but it's a lowly Wharfedale WPR-26. Still rated at 3000W, though!

A strange choice of rating, given that relays are rated in amps and a maximum voltage. You might multiply say 300v by 10A (10A AC is a common relay contact rating) and get 3000W, but you can get 3000w by an infinite combination of volts and amps, a lot of which will exceed 10A.

I’m sure the product itself is just fine for normal applications, it’s just their choice of rating that gets me. Plus the wide variety of ‘watts’ available also makes the rating very vague indeed.

Given that an 8 ohm speaker provided with enough voltage to give a 10A current is using 800W, 3000W is around 19A and the contacts will almost certainly have fused together (if 10A rating and they aren’t using contacts in parallel).

Not a problem for 60-100W of studio monitor, but you can tell the marketing men have triumphed over the engineers.

[sonics]

I’m sure the product itself is just fine for normal applications, it’s just their choice of rating that gets me. Plus the wide variety of ‘watts’ available also makes the rating very vague indeed.

I thought you'd enjoy that spec. The (rather skimpy) manual refers to "3000W plus". It provides no further details, but does tell me that the IR modulation frequency is 38kHz. I switch less than 50W with it and it does a good job, but so much for the "Professional" moniker.

I may open it up soon, just to see "what's in the box"!

[ef37a]

"19A and the contacts will almost certainly have fused together (if 10A rating and they aren’t using contacts in parallel)."
I have read Wonks (D Self) that you cannot 'uprate' relay current capacity by paralleling contacts? That is, two sets of 5A contacts cannot be used to switch 10A because they won't close/open at precisely the same time.

I suspect this is wrong because almost all loads are inductive to some degree, speakers certainly are and so although the total,final current might be 10A it will take a finite time to get there and so each contact will not experience the full current?

Any relay experts on the strength?

Dave.

[Folderol]

Not an egg-spurt, but have read a fair bit about them. You're right about not paralleling contacts, but as well as the 'make' situation you have to consider the 'break' one. Inductive loads will give a greater arc, and relays are usually slower to break than to make, so I wouldn't like to guess on the effect of differential contact breaking.

Just to make things interesting, some relays have bifurcated contacts, with just the last part of the 'leaf' split. This is to increase the contact area and reduce bounce, but is mainly intended for very low voltage/current reliability.

[Wonks]

I didn’t think of that, Dave, though I’m not 100% convinced that relay contacts in parallel don’t have some small benefit in increasing total current carrying capacity, but you might need all four poles of a four pole relay to do so, and then probably not by much and certainly not doubling the capacity. Worst case current for welding contacts is breaking DC, where 10A AC contacts are normally derated to 3A DC, so you might possibly say that 12A AC might be possible with 4 poles in parallel given that each contact is only carrying 3A max when starting to open. Also, given the much more variable and dynamic nature of audio waveforms, the current will almost always be less than peak current.

I can see that contacts from different relays in parallel could always have individual relays opening in a similar sequence and so one would always be the last to open, and so have to break against the total current at that moment in time.

As a professional reviewer/approver (and often re-designer of control panel drawings), with each panel sometimes involving hundreds of relays and contactors, I can’t say I’ve ever seen relays in parallel to increase current capacity done, and I’d certainly have insisted on a higher rated relay (or a swap to a contactor) rather than parallel contacts being used. I certainly wouldn’t be happy with contact ratings only slightly higher than the contact rating being used. But you don’t know what other circuit designers might do if pushed for space and switching capacity.

[ef37a]

Hi Will and Wonks. Yes, I can see the problem with arcing on switch off but if we stay with high current, low voltage audio I don't think there is much of a problem? AC is self extinguishing to a large extent anyway.

I would also not rate doubled contacts per contact either but I think there is some room to increase the overall current rating?

Dave.

[Wonks]

I was just thinking aloud that given the '3000W' rating they might have tried to increase the current capacity of a typical small relay somehow, but I doubt it. But without taking one apart, we'll probably never know.

True that AC is self-extinguishing to an extent, but push the current to its limit and the arcing can first cause pitting, and then the reduced contact area reduces the current capacity and then you are more likely to get micro-welding/tacking keeping the contacts together, and then you have no switching.

[Wonks]

Looking at the manual for the Wharfedale WPR-26 MkII, the current capacity per channel is given as a max of 15A, which is feasible with the right relay choice.

15A gives 1800W into 8 ohm speakers, so a reasonable amount (though I wouldn't like to push it right to the limit). The primary design use for the unit (from the manual) seems to be hi-fi or A/V showrooms to select different speakers rather than demoing big PA systems, so it's very unlikely people will be putting anything more than a couple of hundred watts through at most.

[Folderol]

I wonder if snubbers would be any benefit under these conditions - with smaller resistors and fatter caps. I can't recall seeing it done.

[ef37a]

I wonder if snubbers would be any benefit under these conditions - with smaller resistors and fatter caps. I can't recall seeing it done.

Funny you should say that Will! I once built a simple speaker switcher for guitar cabs using a 5A changeover foot switch (one amp in, select either cab)
As the amplifier was a valve OP stage some people were worried about the fact that for a brief instant the load would be disconnected. I fitted 100nF caps (630V, total over kill but wot i had) across the contacts so that at least some current could flow for the O/C instant.

In theory of course the caps did cause a degree of crosstalk into the unselected speaker. Not acceptable perhaps to the hi fi breed but this was of course "only Rock and Roll"!

We had a much more complex relay switcher and that had no such 'bleed' caps and that must have switched speakers thousands of times and no amp problems ever ensued AFAIK. Mind you, 'our' valve OP stages had a bit of a trade secret magic that gave some protection against an O/C load.

I also understand that a common form of failure in 70's Japanese transistor hi fi amps was the DC protection relay in the output circuit? But I have no idea of the nature of the fault. Welded contacts?

Dave.

[James Perrett]

I also understand that a common form of failure in 70's Japanese transistor hi fi amps was the DC protection relay in the output circuit? But I have no idea of the nature of the fault. Welded contacts?

In my experience the contacts go intermittent and eventually stop working completely. I've had a few Japanese amps that require a sharp tap before they'll start working.

[Folderol]

I also understand that a common form of failure in 70's Japanese transistor hi fi amps was the DC protection relay in the output circuit? But I have no idea of the nature of the fault. Welded contacts?

In my experience the contacts go intermittent and eventually stop working completely. I've had a few Japanese amps that require a sharp tap before they'll start working.

That was my experience too. Although in some cases of you kept 'aggressively' switching them back and forth they'd sometimes start working again... for a while