RN65D Vishay / Dale Precision Resistors?

[Structo]

Anybody know why when you order the RN65D Vishay 1% resistors why it lists them as 0.25 Watt (1/4 Watt) on the order page.

But when you look on the catalog page it lists the RN65D series as 1/2 watt?

I got some a week or so ago and they were the same physical size as the ones commonly used in the ODS amps for plate resistors.

http://www.mouser.com/ProductDetail/Vis ... uk6A%3d%3d

The only RN65 one that comes up as a 1/2 watt is the 10M ohm one.

The CMF60 series comes up as 1/2 watt and 1%.

Just curious why the RN65D resistors are the recommended ones?

[angelodp]

Hey Tom , what are you building?

Ange

[jaysg]

It's a MIL-spec resistor, so it's derated. That causes confusion. Go with whatever the Vishay/Dale data sheet says for "nominal" and know that it's fine for a plate resistor.

[edit] You can see that it's a 0.5W part, therefore it's equivalent to a 1W commercial part.

[Structo]

I figured it had something to do with the military rating system.

I just thought it strange on one page it was rated as 1/2 watt then the next page said 1/4 watt.

Yet I knew it was a type of resistor that many here had recommended for the plate resistors since I had used them before.

So the RN65 series should be good enough for a mere mortal like me.

Hey Ange,
I'm going to re-wire my D'Lite.
I have changed values of caps and resistors so much it looks like a train wreck inside so I am going to re-wire it.

Also get the shielded cable all in the right spots and generally just clean it up.

[Funkalicousgroove]

all Mil spec pn#'s must meet or exceed the rated spec, so rather than create special parts they jus re-label 1W as 1/2W, 1/2W as 1/4W etc.

There are tons of JAN 5V4's out there that are actually 5AR4's re-labelled, you can still see the original glass etch on most of them.

[phsyconoodler]

It's probably been addressed before,but has anyone built amps with and without the Dale resistors?Any comments on tonal differences?

[jaysg]

It's probably been addressed before,but has anyone built amps with and without the Dale resistors?Any comments on tonal differences?

I thought I'd drunk the wrong Coolaid...it's an obvious difference, even A/B'd over time. I'm unsure how to describe it, other than that the signal doesn't seem to die as fast.

[talbany]

Anybody know why when you order the RN65D Vishay 1% resistors why it lists them as 0.25 Watt (1/4 Watt) on the order page.

But when you look on the catalog page it lists the RN65D series as 1/2 watt?

I got some a week or so ago and they were the same physical size as the ones commonly used in the ODS amps for plate resistors.

http://www.mouser.com/ProductDetail/Vis ... uk6A%3d%3d

The only RN65 one that comes up as a 1/2 watt is the 10M ohm one.

The CMF60 series comes up as 1/2 watt and 1%.

Just curious why the RN65D resistors are the recommended ones?
_________________
Tom

Tom

My partner works under water weapons systems and deals with Mil spec. constantly..
The main issue as it pertains to us here with regards to parts resistors caps tubes etc... labeled or sold as MS as we know it exists a large gray area...
Basically when the Military or Gov contractor.. requests a certain part or circuit designed for their application.. (This applies to many layers all the way down to packaging and even shipping)..So mil spec is not considered just 1 aspect of a particular component it's everything..
So with all that being said lets take the RN65 .Manufactures who actually fill the order for the most part can't and won't specify the correct specs design changes etc..because it belongs to the Gov..(The contract lye's in the part # designated by Gov.) Only the Gov can give up the specs...There are websites that you can go to to look them up here is 1...(Don't expect to find everything here)

http://www.dsp.dla.mil/APP_UIL/SpecsAnd ... ntentid=40

In the database you can find all the specs down to the packaging and in some cases find the manufactures that made them..
Here is where the grey area comes in... Manufactures would usually sell off the left overs to the general public being as they cannot advertise the actual mil spec the usually advertise different specs usually under the actual ones for insurance and get rid of them...Other manufactures who knew this loved these parts as they were around the same cost but were getting a far superior part... Why not.. This basically started the whole hype around Mill spec stuff and still goes on today.. For the most part mil spec is turned into a marketing ploy although it may have started as mil spec... demand has kept them in the pipeline although the pricing has changed so your not really getting a great deal..Manufactures don't want to change the name in fear of the demand for the part may suffer...
In the case with the RN65 it may be double the wattage you don't know for sure unless you see the Govt specs (if it in fact carries a Mil spec part#).. So be careful when someone says oh yeah that mil spec part can handle twice that easy...(Not that I am pointing fingers here)

Tony VVT

[Structo]

Thanks for the information Tony, that makes sense, sort of.

It's clear that bureaucratic government has a long reach.

I guess what I don't fully understand is why when I look up a resistor, why I have to be concerned with or care whether a part meets mil spec.
I guess they want you to think it is a real good part.

I think in the amp business, that Harry Joyce brought the mil spec to guitar tube amp building and set the bar pretty darn high with the Hiwatt amps and later his own brand in the way he built and soldered them.

http://www.harry-joyce.com/hjmilspc.htm

[talbany]

It's clear that bureaucratic government has a long reach.

I wouldn't consider it bureaucratic...The Gov hired a company to manufacturer a product with there requirements... company agreed and sealed the deal with their part #...We do the same thing with Mercury Mags..Boogie and others have done it with STR's

I guess what I don't fully understand is why when I look up a resistor, why I have to be concerned with or care whether a part meets mil spec.

You don't!!...

I guess they want you to think it is a real good part. Wink

That and your getting a good deal...

I think in the amp business, that Harry Joyce brought the mil spec to guitar tube amp building and set the bar pretty darn high with the Hiwatt amps and later his own brand in the way he built and soldered them.

No doubt being military trained Harry's technique was mil spec.. one look at his amps leaves little doubt..I don't know if much of the parts he used were mil spec..were they?...Back in the 60's and 70's surplus parts for his amps were more abundant...In today's digital software driven microprocessors...what we are doing with respect to Mil spec now a days is antiquated...with the exception of caps and resistors...

[Bob-I]

It's probably been addressed before,but has anyone built amps with and without the Dale resistors?Any comments on tonal differences?

When I first started building these amps I struggled to get the chirp and shimmer. Scott Lerner told me that I needed to use the RN65's for plate loads and the amp just came alive.

Since then I've A/B'd several plate load resistors and the RN65 always comes out the clear winner.

Resistors are cheep, experiment. The second best (and wayyyy ooofff in the distance) is Xicon 1W CF.

[JD0x0]

It's probably been addressed before,but has anyone built amps with and without the Dale resistors?Any comments on tonal differences?

When I first started building these amps I struggled to get the chirp and shimmer. Scott Lerner told me that I needed to use the RN65's for plate loads and the amp just came alive.

Since then I've A/B'd several plate load resistors and the RN65 always comes out the clear winner.

Resistors are cheep, experiment. The second best (and wayyyy ooofff in the distance) is Xicon 1W CF.

I just ordered a bunch of RN65's are they okay to use throughout most of the amp (with exception of the areas that need higher wattage resistors)

Dumbles are so picky im just worried that the RN65's only "work" very well in some places on the amp

[heisthl]

IMHO - I think you will discover the only place to use them is on the pre and OD plates (V1 and V2). They don't work as well as carbon films for anything the signal passes through, you can hear the difference. I don't even use them on PI plates because they sound different than normal metal films. I've seen people use them as the slope resistor but that doesn't sound good to me either.

[Funkalicousgroove]

It's probably been addressed before,but has anyone built amps with and without the Dale resistors?Any comments on tonal differences?

When I first started building these amps I struggled to get the chirp and shimmer. Scott Lerner told me that I needed to use the RN65's for plate loads and the amp just came alive.

Since then I've A/B'd several plate load resistors and the RN65 always comes out the clear winner.

Resistors are cheep, experiment. The second best (and wayyyy ooofff in the distance) is Xicon 1W CF.

FWIW, I've never seen a Dumble with RN65's in any value but 100K, IE Anything with different plate resistor values did NOT have RN65's.

[talbany]

IMHO - I think you will discover the only place to use them is on the pre and OD plates (V1 and V2). They don't work as well as carbon films for anything the signal passes through, you can hear the difference. I don't even use them on PI plates because they sound different than normal metal films. I've seen people use them as the slope resistor but that doesn't sound good to me either.

Henry
Totally agree


T