So what in solder "sounds" bad, and what can be done about it?

[Steve Conner]

My pet theory for speaker cable audibility is that audiophile solid-state amps are badly designed and not properly tested for stability. Some speaker cables make them give little bursts of parasitic oscillation at certain points on the audio waveform, but with other cables they stay stable. The oscillations cause distortion that is audible, maybe even euphonic to some single-malt-crazed reviewers.

The little output inductor used in traditional solid-state amps isolates the amp from the cable at high frequencies, preventing oscillation. But it seems to be frowned on in audiophile circles. According to my theory, this is because it makes their expensive cables sound the same as the cheap ones!

http://www.audiomisc.co.uk/HFN/Cables3/TakeTheLead.html

[LVS]

Making sure your component has good physical contact with the circuit it is being soldered to, instead of relying on the solder to make that connection for you.

In an Elektor article I once read a circuit board hole should be a tight fit for the component lead (iow, drills of the right size have to be used), for the best possible contact between the copper and the lead. Seems to make sense, though in hobby situations this is often not the case and I must say I never had any problem with it just as long as the solder joint was tidy. Btw, it makes me suddenly wonder if there's any direct contact between an SMT component and the board.

[RedHouse]

Some solder does work badly.
(and hence effect the sound)

I've traditioanlly used 60/40 rosin core solder, never really had a problem with Kester and Ersin "Multi-core" which are my favorites. About 6 months ago I was out of solder at a most inconvienient time (Saturday evening, emergency fix, etc) and I had to go down to a local place called "Fry's" and buy a spool so I could do the work.

The brand was "AlphaFry" (that should have been a clue) and the label read "Cookson Electronics Assembly Materials".
(60/40)

That solder was the weirdest stuff, every joint looked like a cold-solder joint, no matter how many times I re-flowed, it cooled with that non-shiney dull look as if it was a cold joint, and true to form the sound was suffering, it was making a connection but sounded crappy. So bad in fact that later that night I ran into a guy I knew that worked as a mobile auto mechanic and he had his truck outside so I borrowed some solder and re-soldered the stuff I had "fixed" earlier that night, sound quality came back.

The next week I took itr back to Fry's and told them about it, they offered replace/refund and I chose to try another spool thinking it micht have been a bad spool, nope, still had ther weird joints. MNow the funny thing is, another tech friend I know in the area has been using this stuff for a while without problems and he still has a spool, we compared them and his was fine but the stuff I had was shite, same brand, same store.

In 38 years of soldering I've never run into "bad" solder really, but it's out there.

[Alan0354]

yeah, skin effect is really audible, especially when those woofer frequencies are concerned!

[/sarcasm]

It make a difference in the high frequency side. I just hook it up like this because the speaker has separate terminals. Maybe two pairs for woofer is not necessary.

But whether you believe cable make a difference really depend on the quality of your speaker. I did the experiment 15 years ago. I used to have a pair of Kef that was $1000 pair, speaker cable don't seems to be that important because it is not of high quality. When I dished out over $4000 for a pair of JM Lab and hooked up to the exact setup, they don't improved that much as when I tested in the store( where I even brought my own Acurus power amp over to test the speaker). So I tried buying the 12 gauge speaker cable. It make a world of difference even just one pair. So I started experimenting with more pairs and I can hear the difference up to 4 pairs, after that, it really don't improve anymore. Maybe if I have a $20K pair of speaker, it will make a difference.

It is all about the quality of your system. If your whole system is less than $2000 using those Polk Audio, Infinity, JBL or even Kliptch speakers, don't worry about it. If you use audiophile quality speaker, then it become important.

[RedHouse]

It make a difference in the high frequency side

Yeah, it's well documented in the microwave region of the spectrum.

[Alan0354]

My pet theory for speaker cable audibility is that audiophile solid-state amps are badly designed and not properly tested for stability. Some speaker cables make them give little bursts of parasitic oscillation at certain points on the audio waveform, but with other cables they stay stable. The oscillations cause distortion that is audible, maybe even euphonic to some single-malt-crazed reviewers.

The little output inductor used in traditional solid-state amps isolates the amp from the cable at high frequencies, preventing oscillation. But it seems to be frowned on in audiophile circles. According to my theory, this is because it makes their expensive cables sound the same as the cheap ones!

Taking the Lead

There is a lot of truth about people in audio field don't know much about electronics. This is also true about guitar amp. Look at the top quality amps, they are all tubes and you look at the schematics, they pretty much remain the same as 40 years ago. People just copy each other, change a few values and call it their own design. Most circuits are just old Fenders and Marshalls. Then they get into the superstition things like vintage resistors, orange caps, CTS pots and all different funny things.

I was actually very very skeptical about the speaker cable, I did the speaker cable by blind testing using my wife also.

[RedHouse]

... Then they get into the superstition things like vintage resistors, orange caps, CTS pots and all different funny things...

Same with pickup makers then?, all that superstition about proper metals, bobbin cores, magnets, wire type and coating?

[FunkyKikuchiyo]

Some solder does work badly.
(and hence effect the sound)

I've traditioanlly used 60/40 rosin core solder, never really had a problem with Kester and Ersin "Multi-core" which are my favorites. About 6 months ago I was out of solder at a most inconvienient time (Saturday evening, emergency fix, etc) and I had to go down to a local place called "Fry's" and buy a spool so I could do the work.

The brand was "AlphaFry" (that should have been a clue) and the label read "Cookson Electronics Assembly Materials".
(60/40)

That solder was the weirdest stuff, every joint looked like a cold-solder joint, no matter how many times I re-flowed, it cooled with that non-shiney dull look as if it was a cold joint, and true to form the sound was suffering, it was making a connection but sounded crappy. So bad in fact that later that night I ran into a guy I knew that worked as a mobile auto mechanic and he had his truck outside so I borrowed some solder and re-soldered the stuff I had "fixed" earlier that night, sound quality came back.

The next week I took itr back to Fry's and told them about it, they offered replace/refund and I chose to try another spool thinking it micht have been a bad spool, nope, still had ther weird joints. MNow the funny thing is, another tech friend I know in the area has been using this stuff for a while without problems and he still has a spool, we compared them and his was fine but the stuff I had was shite, same brand, same store.

In 38 years of soldering I've never run into "bad" solder really, but it's out there.

Was it RoHS solder? I've found most solders I find walking into a hardware store or Radio Shack (no Fry's in my neck of the woods) are the lead free kind, which really take some getting used to. In fact, it sounds a lot like what you're describing. Reworking one kind with another can be a real mess too, if I remember correctly. I've used some that are okay, but they are pretty pricey. I won't make the switch until it becomes legally necessary, or someone proves to me that it is actually unhealthy to play a a guitar who's pickups are soldered in with Pb solder.

[Steve Conner]

The matt "dry joint" appearance certainly sounds like lead free solder. I hate the stuff too!

Some high-end hi-fi speakers dip very low in impedance at certain frequencies. Low enough that if you had long speaker cables, you could maybe hear a lack of output at those frequencies with 18 gauge lamp cord, and four 12 gauge runs in parallel would fix it.

Fine strands don't help skin effect unless they're separately insulated. If the strands are bare, HF current hops from one to the other to stay at the surface of the bundle. Jim LeSurf shows evidence to prove that in the article I linked.

[Jazz P Bass]

Component Hole Size

In an Elektor article I once read a circuit board hole should be a tight fit for the component lead (iow, drills of the right size have to be used), for the best possible contact between the copper and the lead. .

I will have to disagree with this statement.
The amps that I have "worked" on that have component holes that are a little bit larger than the component lead are a PITA.
#1: there is not enough room for the solder to wick up the lead (meniscus).
On a double sided board this will lead to failure.
#2: it makes it exceedingly difficult to remove all the solder when changing out a component.
Can you say "pulled up pad".
.022" (.55mm) larger than component is standard.
I have attached a nice PCB reference document.

[RedHouse]

No it was 60/40 lead solder (or so it says on the label) it could be mis-marked I suppose.

[Alan0354]

Same with pickup makers then?, all that superstition about proper metals, bobbin cores, magnets, wire type and coating?

There are certain truth, I don't believe in bobbin material. Fovar wire has thicker coating so the inter winding capacitance is lower, that is the major thing. Don't know enough about metal and magnet as I am not a pup maker.

Bottom line, you have to look at each item individually. I don't buy the CTS pot, I don't believe in vintage carbon resistors and I don't believe in caps, only need to worry about the voltage rating and the ESR.

[Alan0354]

Yeah, it's well documented in the microwave region of the spectrum.

I am an RF design engineer and I know how to calculate skin depth. AND I calculated the skin depth of 20KHz, it is about 1mm( I don't remember the exact number) or so. That is much less than the radius of a 12 Gauge wire.

The formula is:

Skin depth =1/{square root of [\pi*freq*mu*(conductance)]}

conductance of copper =6X10EE6. Double check the number.

Here is an article about this:

Skin effect - Wikipedia, the free encyclopedia

[RedHouse]

...Bottom line, you have to look at each item individually....

Actually the bottom line is ...things are the sum of their parts, whether you believe, or not.

[Mike Sulzer]

I am an RF design engineer and I know how to calculate skin depth. AND I calculated the skin depth of 20KHz, it is about 1mm( I don't remember the exact number) or so. That is much less than the radius of a 12 Gauge wire.

The formula is:

Skin depth =1/{square root of [\pi*freq*mu*(conductance)]}

conductance of copper =6X10EE6. Double check the number.

Here is an article about this:

Skin effect - Wikipedia, the free encyclopedia

(Alan's link has a nice plot about halfway down that verifies that the skin depth for copper is a bit less than 1 mm for those who do not want to check his calculation.)

It is amazing that actual effects get ignored or laughed at by the same people who swear by things that not only seem ridiculous when computed, but certainly do not stand up to real AB tests (like the difference between a ceramic and a polypropylene capacitor, especially with the full .5 Meg tone pot in series).

Few people realize that it is the mu term in the equation for skin effect that allows a steel core pickup to work. The loss in the cores is still very important, but without the mu term you would have a much greater loss in the midrange and lows. (The highs probably would still be OK because the inductance resulting from flux leakage is in series with the resistance.)