wirewound non-inductive 1% resistors

[jewilson]

Both mills and RCD make great non-inductive wire wound resistors. I have test these resistors using impulse and square waves at 4 MHz and they look good. Of course they maybe some inductance in the resistor but that true for most all passive components at some frequency.

As for carbon compositions, I stay clear of them for audio. Having said that, they work ok for Guitar amps and some high voltage application.

[fdegrove]

Hi Jay,

If a resistor reacts against a magnet bar, what do you call this resistor?

That would be a magnetic resistor, it could be inductive or not.
The magnetism comes from the use of ferrous content, either in the resistive layer, wire or endcaps and leadout wires.

So, in theory, you could have a non-inductive yet magnetic resistor.

In my current Aleph setup I use Painton wirewound (made in England) for the MOSFET Source. This resistor doesn't react against magnetic field, as opposite to Dale resistor

The Painton WW resistors were said to sound really well. Unfortunately they're out of business for a number of years already. There may be some NOS left but not much IMHO.

And anybody know why it has to be wire-wound?

It doesn't have to be WW types.
It's just that the higher power dissipation resistors inevitably are of that type if you want a single component.

As with anything else, here too sound quality can vary alot.
Although I feel they should be non-magnetic, the fact that most are inductive isn't a big problem.
A good, ear-tuned x-over can take this into account as most use inductors already.
This, however, will be entirely design dependent and I can well imagine that replacing these inductive resistors with non-inductive ones would alter the perceived result sonically.

Exactly the same effect as it's use in audio circuits. I wonder if anyone have ever tried this resistor in crossovers and would report the result.

To my mind, there's no reason why one wouldn't here the same differences amongst components in x-overs.
This is a known fact amongst the better speaker designers,so it's likely not just your imagination.

Cheers,

[SimontY]

most use inductors already.

Apologies for being anal, but what speakers use an inductor in series with the tweeter??

I have tried only two tpyes of resistor in speaker x-overs: the crap white ceramic ones, and MOX (metal oxide) from Audiocom ( http://www.audiocom-uk.com/ ) (their new site is only half finished ). MOX is a fair improvement over the nasty white ones.

What does one buy to upgrade from MOX?? There must be something better...

Audiocom sells:
Precision foil resistors (£4/5 each,50ppm temp.,1% tol.,3w)
Vishay VSRJ Bulk Metal Foil (£5 and up,4ppm temp.,1% tol.,?w)
Precision Wire Wound (? details ?)
MOX (1 or 5% iirc, and ~ 60 pence each)

Anyone know what any/all these sound like in x-overs?


Cheers,
Simon

[fdegrove]

Hi,

The sentence says x-over, not just tweeter section.

A good, ear-tuned x-over can take this into account as most use inductors already.

Anyone know what any/all these sound like in x-overs?

I assume they sound pretty much the same as when used in active circuits.

Probably the easiest way to find out is to try some equal value/wattage resistors of various makes and technogoly in series with the speaker cable and have a listen.

Cheers,

[Jay]

Thank's for the great answers, Frank.

[QUOTEApologies for being anal, but what speakers use an inductor in series with the tweeter??[/QUOTE]

Most old amplifier designs use inductor (usually in parallel with resistor) in the output to combat oscillation or uncertainty with the speaker/crossover impedance (This approach is still used in modern hi-end amplifiers). And this inductor is in series with the tweeter. (If only this is relevant to the question)

[SimontY]

Aha, very interesting! I've heard of the amp inductor, I'll just keep quiet now...

Fred, putting them in series with the whole speaker sounds like a great way of testing them out... except I'd have to spend a fortune to do it, and the ones I didn't use would be wasted

Maybe this is possible for others.

One more thing: I don't know what they sound like in active circuits either


-Simon

[fdegrove]

Hi,

Fred, putting them in series with the whole speaker sounds like a great way of testing them out... except I'd have to spend a fortune to do it, and the ones I didn't use would be wasted

All you need is a pair of each to do some listening tests...
Otherwise I'd take the advise of other members here and try Mills,Welwyn.
Almost any quality WW resistor sounds better than those horrible white sandcast affairs to my ears.

Btw, my first name's Frank not Fred, unless you were addressing someone of course....

Maybe Russ Andrews can head you in the right direction?

Cheers,

[SimontY]

Hi,

All you need is a pair of each to do some listening tests...

-Yes, but when a pair is ~15Euros!!!

try Mills,Welwyn

-Ok, I'll look 'em sometime soon, thanks

my first name's Frank not Fred

-ah, sorry Frank, I guessed... you can't see the name things when writing posts

Maybe Russ Andrews can head you in the right direction?

-Russ doesn't sell resistors, but next time I order something from them I will ask what they like... they might have something to say, who knows! (they're very knowledgable)


Thanks Frank,
-Simon

[BigMacX]

WRT to the original message, when I was building my Watt/Puppy clones I got some Caddock resistors from here

http://www.rhopoint.co.uk/

And as they're an industrial supplier there also a fair bit cheaper then your typical hi-fi part supplier

Mac.