Best SMD resistor/capacitor for GC

[Ipanema]

Hi,

I am building my GC with SMD components, since GC sounds better with short signal path and less parasitics compoents as some claims. I know this is nothing new.

Pls advise me on the type of SMD resistor / capacitor that will sounds good for GC. I have in mind to use 1206 size thick film resistor and 0.1uF ceramic capacitor for PS decoupling since 1206 size is easier to handle by my hand.

I also come across thin film resistor, which is more expensive. May I know what is the difference between thick film and thin film or is there any other types of SMD resistor worth considering?

As for capacitor, some tantalum SMD types claim to have very low ESR. Will this be better than ceramic SMD?

Thanks for your advise.

[Ipanema]

come on guys. Anyone with experience on SMD parts.

[Arius]

Well, here are some comments....

1) Resistors. Metal film SMD is superior to thick film. See Vishay-Dale's site for a useful appnote with noise figures.

2) Capacitors. Ceramics are a no-no. Poor audio quality to due wide tolerance to temperature changes. Has microphonic behavior too. Tantalums - I don't use them due to poor reliability. NPO or film will do nicely. As for the necessary electrolytics - well, you need them. SMD versions tend to have a larger footprint.

Have fun with your GC.

[peranders]

Originally posted by Ipanema
come on guys. Anyone with experience on SMD parts.

I use SMD parts, just to scare people off.
Have you seen this?

[peranders]

Originally posted by Arius
1) Resistors. Metal film SMD is superior to thick film. See Vishay-Dale's site for a useful appnote with noise figures.

Noise is hardly any issue in a Gainclone.

Originally posted by Arius
2) Capacitors. Ceramics are a no-no. Poor audio quality to due wide tolerance to temperature changes. Has microphonic behavior too. Tantalums - I don't use them due to poor reliability. NPO or film will do nicely. As for the necessary electrolytics - well, you need them. SMD versions tend to have a larger footprint.

Tantalum isn't particulary bad. I have it in automative products with pretty harsh environment.

Ceramic caps is ok for decoupling but I avoid it in the signal path. In the picture above you can see a polyphenylene sulphide caps from RIFA, the big white one.

[peranders]

Originally posted by Ipanema
I have in mind to use 1206 size thick film resistor and 0.1uF ceramic capacitor for PS decoupling since 1206 size is easier to handle by my hand.

If you can manage 1206 you can also manage 0805, not much difference. 0604 and smaller requires some extra skills.

[Ipanema]

Thanks for your reply.

Hi Arius,

Have you use those metal film SMD from Vishay? Do you hear the difference over thick/thin film type?


Hi Peranders,

What type of SMD resistor and capacitors do you use? I mean material. Do you hear any difference with difference resistor and capcitor type?

Your board layout looks nice.

Regards.

[JensRasmussen]

Originally posted by peranders

If you can manage 1206 you can also manage 0805, not much difference. 0604 and smaller requires some extra skills.

At work I rework (by hand) SMT boards using 0603, 0402 and 0201 on a daily basis.

With some patience I find SMTs are easier than through hole components.

\Jens

[Arius]

P-A's right about resistors. Noise is hardly an issue with GC's. Just wanted to mention what folks think is the best (bulk metal foils aren't readily available in SMD, I think). BTW, I haven't used the SMD metal film glass substrates for audio. Merely referring readers to Vishay's AN0003.

Likewise, for caps, I use ceramics all the time to decouple rails but I do know many of the ppl here frown on ceramics for audio applications, even for supply decoupling. My company's design policy is not to use tantalums unless they are organic polymer tants. Those are more reliable and need less derating.

So in a nutshell, I mentioned what I deemed to be the better materials for SMD parts for audio use. Objectively, they will make a difference (albeit small) but subjectively, it's up to the DIY-er to experiment and listen.

This forum after all, have members who can hear the difference between brands of exotic resistors, capacitors, heck - even heatsinks. A reminder to folks to not to quickly brush off exotic parts. Nor am I a proponent of such parts. Happy DIY-ing.


PSST: Hey P-A, just wondering. In your SMD GC, why do you use 630V caps for the PSU diode snubbers? I use 63V caps for mine and I'm wondering if I missed something. Thanks.

[peranders]

Originally posted by Arius P-A's right about resistors. Noise is hardly an issue with GC's. Just wanted to mention what folks think is the best (bulk metal foils aren't readily available in SMD, I think). BTW, I haven't used the SMD metal film glass substrates for audio. Merely referring readers to Vishay's AN0003.

It is possible (more possible) that small resistors have more different properties than larger types.

Originally posted by Arius This forum after all, have members who can hear the difference between brands of exotic resistors, capacitors, heck - even heatsinks. A reminder to folks to not to quickly brush off exotic parts. Nor am I a proponent of such parts.

... who THINK they can hear... Most of such claims have never been done in blind tests, altough it might feel good with certain parts.

Originally posted by Arius PSST: Hey P-A, just wondering. In your SMD GC, why do you use 630V caps for the PSU diode snubbers? I use 63V caps for mine and I'm wondering if I missed something. Thanks.

I like the heavy duty RIFA caps and they can't be found with lower ratings. 63 V is a bit little when you have 24 VAC => 2 x 24 x 1.4 Volts.