NOS components on ebay, why?

[sipuser]

I see a lot of NOS components on ebay like these OLD OHMITE LITTLE DEVILS RESISTORs

http://cgi.ebay.com/3-OHMITE-LITTLE...6595922779QQcategoryZ7275QQrdZ1QQcmdZViewItem

I thought the idea was to upgrade the components with new parts. Can anyone clue me in to the why.

I see capacitors also.

http://cgi.ebay.com/NOS-Capacitors-...81132555QQcategoryZ111602QQrdZ1QQcmdZViewItem

When and where is it ok to replace with NOS.

A little confused on this subject...

 

[rulerboyz]

Quite simple. Not everyone is interesting in upgrading the technology of a particular piece of vintage equipment. To restore something in the purest sense would entail trying to use original parts with the goal of trying to match what the unit was like when it was originally made. And this can also mean that the most you can typically hope for it to get it to perform the way it would have when it was first produced.

 

[phidauex]

NOS is great sometimes, for the times when the future hasn't been good to a particular technology's availability or quality, or for when you are obsessed with originality, or have a collectors item that simply MUST remain original.

In the case of caps though... Sounds like a bad idea, some types of capacitors have a limited shelf life.

Same thing with rubber bits, NOS can sometimes mean a dried out, cracked little shrivel. But in audio, you don't see many of those, mostly thats an auto parts NOS worry.

Sometimes you get cool things too, that were hiding in the back of a shop somewhere, like the few Phase Linear 3500 Series II preamps still in their original packaging that have been on ebay recently.

peace,
sam

 

[tcdriver]

Nos

I have had some audiophiles tell me that they prefer the sound of carbon composition resistors and paper capacitors. That is the reason you see this kind of stuff advertised on the popular auction site.

Some other people insist on replacing these very same components with newer parts as an "upgrade" for older equipment. To each his own.

 

[blue_lateral]

A lot of old equipment was designed around carbon comp resistors. A long time ago carbon film was pretty much considered crap. They didnt deal with the surge currents in tube equipment very well and were considered unstable. In equipment designed around them this isnt a problem, and people are finding out about the good qualities of carbon film. Metal film is usually ok in tube stuff, but it doesnt look right in something old. Also film resistors are slightly inductive. This could be a problem in high frequency circuits. Tektronix (oscilloscopes) used to use Allen Bradley 10 ohm carbon comp resistors for fuses in their power supplies. No modern resistor substitutes well for this.

Ohmite little devils are still available new, BTW. I ordered some from digi-key a couple months ago. Mouser has Xicon carbon comp resistors which are rated 5%, but every one I have measured has been within about 1 or 2%. I really like those.

Carbon comp resistors can drift in value with age. Still the ones in that auction had the cabinets for the assortment, and if you were going to try to keep some around, the only assortments available new that I am aware of are 1/4 watt. Thats too small for most tube applications. Those ones in the auction went up to 2 watt also. You can only get up to one watt new AFAIK, and the one watt ones are expensive, about $2 each.

NOS capacitors are kind of scary IMHO, but if they were some technology that doesnt have a high failure rate (like silver-mica or mylar) then why not? I would warm to that idea pretty quick if whatever I needed wasnt available new.

John

 

[sipuser]

Good points all,

I guess I could slowly replace the capacitors and not touch the resistors unless theres a problem, listen and then decide.

The Fisher 101 sounds excellent now in orginal form not sure how much longer it will last with all orginal components.

Wondering now which has more impact of sound quality resistors or cap's? More reading....