[DCameronMauch]

Been messing around with some surface mount pcb layouts. But I have no knowledge about the audio qualities of the various choices for SMD passives. There seem to be lots of options for resistors. Thin film. Thick film. All kinds of materials and substrates. I imagine metal foil would be the best. But too expensive. Looking for something under $1 each. Thanks!

 

[JohnFerrier]

I use Vishay bulk metal foil resistors. Though I'm not sure of the audible effect, I'm aware that in general the larger components (say a 2516 package v 1206 v 0805) tend to have slightly better specs...like lower noise, smaller tempco. I suppose that it's like how parallel devices tend to have a sqrt of N reduction in noise. Also, Tantalum Nitride resistors are well regarded and less expensive than bulk foil.


JF

 

[DCameronMauch]

Hello. Thanks for the response. You talked me into going with 1206s. I got them to fit by flipping them to the back side of my board. Also, four resistors need to be 750k and 0805s only seem to be available upto 300k. I saw Vishay does have some Tantalum Nitride SMDs. But some others had even better noise specs. This who topic is still very unclear to me. Anyone else have any experience with SMDs?

 

[aos]

Wait wait wait, Vishay bulk metal foil resistors in SMD?? Where from?

 

[JohnFerrier]

Quote:

Originally Posted by aos Wait wait wait, Vishay bulk metal foil resistors in SMD?? Where from?

Texas Components for one:
http://www.texascomponents.com/

Vishay's selection
http://www.vishay.com/resistors-discrete/metal-foil/

The ones I use (the VSM series, 0.01%, 0.6 PPM) are built to order, so have 14 week lead times. Non-reference grade versions may be more available.


JF

 

[JohnFerrier]

Quote:

Originally Posted by DCameronMauch I saw Vishay does have some Tantalum Nitride SMDs.

IRC also makes "TaNFilm" resistors. Beyond cost, presumably the Achilles’ heel of the bulk foil NiChrome parts is moisture can deteriorate them if the passivation layer is compromised… Though the circuitry is cleaned in a dedicated dishwasher, I've not ever noted a problem...

http://www.irctt.com/pages/tanfilmvideo.cfm


JF

 

[aos]

How do you manage to get them? From what I see minimum requirement in most places is 1000, and even so only a very limited set of values is offered - most distributors don't stock this stuff. Texas Components doesn't have a minimum order though.

 

[JohnFerrier]

I recommend calling Texas Components. Though perhaps not the quickest to respond all the time, they are one of my favorite vendors to deal with. They deal with lower quantities. Also, FWIW they are a Vishay approved mfg so they laser cut and package the components local (rather than Vishay Israel).


JF

 

[aos]

I was under the impression that the bulf foil are made in USA. In fact until a year or two ago the only way to get them was straight from the manufacturer - which was most definitely a US division - and they sold to US only, leading me to believe that these were restricted military grade components. Vishay as a whole had a lot of distributors, but that particular plant was selling direct only.

What are the prices like? 10 bucks per each or more?

 

[JohnFerrier]

$7 to $15 depending on value and tolerance...