Best SMD resistor/capacitor for GC

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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. :D

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.
 
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.
 
Arius said:
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.

Arius said:
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.
 
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.
:D
 
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.
 
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.
 
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.

Duh! I did forget something. Diodes/caps in a bridge sees twice the voltage. My GC is OK. Running 2 X 22VAC but my soon to be ready Leach clone has 100V caps off 40V AC rails (rest of PSU caps are 63V). I'll get that fixed. Thanks.

Back to the topic, I tried fiddling with a SMD layout for GC but found that it's hard to be more compact than my current layout using 1206 resistors & other SMD parts.

The attached placement has a Zobel, both high/low freq decoupling caps, bypassed feedback cap, input HF filter all in a nice, tight space.
 

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PA150 means three 3886 paralleled, able to deliver ~150W into 2 ohms.

It is an inverted configuration, the trimmer is to adjust the DC offset. I measured the DC offset to be < 1mV after adjusting each trimmer.

My plan is to bridge 2 of these broads using DRV134, to deliver 300W into 4 ohms.

P.S. I have to admit that most of the idea came from this Jeff Rowland Model 10, which also use SMD parts.

model10-2.jpg
 
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. :D

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.


This topic was open almost 12 years ago. Today, what do you think about SMD audio caps?
 
NP0 ceramic are even more available for audio duty.
X7R are still available for local supply rail decoupling.
Both of the above are now widely available in MLCC and give much higher capacitances than were available 12years ago.
Metal film in 1% are more widely available but there is a big variation in pricing.
Metal film 0.1% are still expensive, but fortunately only required in very few locations.
Metal oxide 1% 100ppm/C or 150ppm/C have become more available at quite cheap pricing.
Take care to check datasheet for maximum voltage and maximum dissipation. You do not want to get to close to their limits and amp performance is demonstrably better if you operate well below maximum limits.

There are a few doing film caps in smd, but they are difficult to find stockists and prices can be high due to low turnover.
 
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