Circuit board components


#1

I’ve been reading audio mags since the early 80s, and have gotten lost in the tangle of lists of tubes, caps, resisters, diodes, where to use which type, and I’ve been wondering how the new smt components compare with the older tech. Has anyone compared tolerances? How can those gnat-sized caps possibly hold an adequate charge, compared with some of the leaded (and huge in size and cost) caps? How about the new types of solder and glue? Any thoughts on this? How can manufacturers lure us with megabuck products when they’re using seemingly almost identical circuits found in inexpensive mass market stuff?

I’m not an e.e. or tech, but has anyone delved into this? Just wondering.

Tomajj.

P.S. First time poster, be gentle.


#2

Welcome, Tomajj!

An interesting query.

I know capacitors can be made smaller as their constituent parts are now able to separate charges with psychically smaller but equally effective dielectrics.


#3

Well, of course companies must charge megabuck prices if they make the components psychic . . .

I realize that Elk was the victim of a spell checker run amok. But the way things are going (Siri, Cortana, etc.) how long will it be before our playback software can pick music based on our mood at the moment, our tastes in past listening, and so forth? Not really psychic but to me a little disturbing, which is why I keep those digital assistants turned off.


#4

But you must recognize psychically smaller is a Good Thing. :slight_smile:

I cannot blame a real-time spell checker for this one, just an old-school error on my part.


#5

Well, I was hoping that someone ( Paul, or other solder slingers who are at the bench now and then ) would chime in on this. I haven’t soldered anything since… we’ll, a couple dyna kits Dyna 400, and a Dyna preamp, and a couple of caps to load an ORTOFON MC cartridge. Is all that smt stuff working at lower voltages? No more resister or cap shootouts? Oh, man how do I shut off this #%&÷@₩ spell checker?

Hey, Paul, any of your techs have any stories to tell? You know, from the trenches ERR benches?

T.


#6

Your question is kind of wide open.

For higher power products, e.g. amps or power conditioners many of the components will need to be fairly big, they might have to dissipate a lot of heat and probably thru hole works best.

For lower power audio frequencies either thru hole or SMT work well.

For higher digital frequencies SMT is the way to go. SMT is much denser. The parasitics of SMT parts are much better (lower inductance from shorter (or no) legs and smaller sizes, lower capacitance from smaller sizes, smaller loop areas to transmit or receive RF, everything is closer to ground so things are quieter…)

You can get essentially as good or better resistors, inductors, ceramic caps, etc. in SMT as thru hole. The raw capacity of capacitors is related to size but (outside of power supplies) the capacities available in SMT packages are fine. Tho it didn’t used to be as true there are some fine capacitors available for audio, e.g. film caps with good dielectrics…

For the DirectStream SMT was the only way to go. Noise matters a lot and things would be much nosier without SMT. Many of the parts I use just aren’t available in non-SMT packages. I use 0.1% +/-25ppm / degree C thin film resistors and 2% caps at all critical places. They aren’t cheap but they are quality parts.

Not being able to do reworks as easily is a problem in SMT, so I had to just not make many mistakes and/or make friends with a good tech.

Glue isn’t an issue if you only put SMT components on one side of the board (they are kept in place until they’re soldered by the surface tension of the solder paste.)

I have no interest in working with non SMT designs - I can get what I need in SMT, the boards are smaller and more reliable (e.g. less stress on smaller components when a board bends or vibrates.)


#7

To add another view to Ted’s, when it comes to older analog designs like you might find in BHK we did the opposite. Relied upon good old fashioned through hole components. For the higher voltage tube-based circuits the ability to use hand-selected resistors (which we pay a king’s ransom for) and capacitors was critical to the success of the design. So, Ted could not build modern DACs as good as his designs are without SMT and Bascom couldn’t do his work without traditional through hole.

I suppose in the end it really depends on what you are doing and why. Part of your question is interesting. If we’re using essentially the same parts as older designers did how come the costs for equipment skyrocket? It’s a good question. In our case our products always reflect a direct relationship between the cost to build them and their retail price. In that way we can stick to one of PS Audio’s core principals: high-value. Other companies may price their products in the stratosphere because the market will bear it or the higher price adds that stamp of luxury. Imagine paying $1,500 for a Rolex. It would no longer qualify as a luxury item.

Our interests don’t line up with building luxury items. We’re all about performance, value, and community.

But, that’s just us.


#8
Paul McGowan said

Our interests don’t line up with building luxury items. We’re all about performance, value, and community.

But, that’s just us.


And we greatly respect and appreciate you, and your philosophy. Truly.

Thanks Ted and Paul for your comments. Fascinating reading and a great initial question.


#9

I have to agree, excellent insight into the real meat and potatoes of the right components for the particular circuit being built. Your answers were the knowledge I was seeking. I understand larger components for higher voltages, as I took the plunge into tubes with an Audible Illusions mod 3 in the mid 90s, first CD player pd 65, and a counterpoint solid 2- knocked my socks off!! First time I could actually hear the hall, players turning their sheet music. And that was on those reissues of Reiner, CSO made in the 50’s. Had NO idea that they had the ability to pick up all that detail with 1950 era recording equipment. Now I’m retired, and I can’t even pick up the counterpoint anymore. It weighs 85-90 lbs! Sincere thanks for sharing all that info (especially from the boss).

Best Regards and ttfn, Tomajj


#10

I am a newbie and have just discovered PS Audio over here in Blackpool UK … I have just registered myself with the site after being totally blown away by the pre amp I purchased second hand from a dealer Fanthorpes in Hull UK … A PCA-2 Pre Amplifier,

The dealer showed me the amp on a day out across the country in North Yorkshire. I must add that he did say they were not PS audio dealers…

As I was walking past the shop I heard Miles Davis and had to see what was giving such a real and live recording… It sounded like the Artist was on the premesis…

The PCA-2 was running into 2x Krell power amps… Anyway I was not leaving without the pre amp at least as I had leak amplifiers and discussed using the pre with them. The rest is history… The pca is now powering a pair of Leak TL12 mono valve amplifiers and sounds glorious…I have a Linn Basik Turntable for front end’ I have just put a new akito arm on it a 2b as the old one had bearing issues years ago. I have owned it since 1990…I have owned all kinds of audio eq and have never felt really happy

I have been waiting for years to find a sound that is genuine and emotive… Just like to say thanks to all at PS Audio for such great dedication to true audio. Have looked at some of the very informative you tube video’s and find the whole company well informed and a breath of fresh air. 103_gif103_gif103_gif

Yours very very happy…


#11

Great report and welcome to the forum!


#12

Welcome, ducakrugs!