# Best type of solder for audio quality



## mojo

I have been experimenting with different kinds of solder for use in audio. My experiments have all been on cables but presumably it affects PCBs as well.
   
  I mostly use 60/40 leaded solder. IMHO all the lead-free stuff is crap, takes too much heat to flow properly and make a really good join plus the fumes are worse than the leaded stuff. There is still some variation between types of leaded solder though.
   
  The main type I use is Goot SE-06008 as it flows well but is also malleable enough to make bridges when doing matrix board or cable joins. It is 60/40 183-190C 0.8mm multicore I believe with flux built in. I also tried some Goot SD-60 which has much more flux and consequently is more "wet" and hard to make bridges with. It flows very easily and is good for making very "close" and minimal joints. The SD-60 is designed for SMD work so is not ideal for making cable joins from an ease-of-use point of view, and I am still in two minds about the sound quality. I think a good metal-on-metal joint with SE-06008 is superior most of the time which I think could be down to the SD-60 working in between everything and thus forming a layer between the two surfaces. On the other hand in situations where it is hard to make that type of connection with normal solder such as wires direct to SMD ICs it might be better.
   
  I suppose it really depends on the application then. I also have some Almit KR-19 which is 0.65mm and less wet than the SD-60 but still quite clingy. It is easier to work than the SE-06008 but seems not to make as good joints, but I have not done any ABX testing so it may just be the result of inhaling whatever they put in it... Seriously, it smells floral!
   
  Anyone else noticed any differences between types of solder?


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## FallenAngel

Use eutectic solder like 63/37.  Personally, I'm a huge fan of Cardas Quad solder, melts at low temperatures, stays liquid as long as you need and has enough flux to make good joints every time easily.


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## Uncle Erik

I love regular Kester 60/40. It makes wonderful, shiny joints.

Radio Shack 60/40 is pretty good, too.


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## daveDerek

when Merlin Music Systems was forced to go to lead free solder to comply with EU regulations, they unexpectedly found that it took their speakers to a higher level of performance. i'll bet that this type of talk will make some roll their eyes.  some folks hear no differences amongst cables while others hear differences ranging from subtle to significant. i think you'll find the same with solder.


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## mojo

Well I am quite sceptical about cables generally speaking. There is a difference between the cheap ones and reasonable quality ones, but not between good £10 cables and £500 cables. My suspicion is that a combination of poor soldering and low grade plugs is what ruins the cheap ones. The quality of hand-soldered parts from Chinese factories in particular nose-dived when ROHS came in. I'm all for removing dangerous substances but it's frustrating that no-one has managed to make a good lead-free solder yet.
   
  The claims by Merlin don't match my own findings. I suppose there were unlikely to say that it made the sound worse since that would mean all their products received a downgrade. The biggest problem seems to be the amount of heat required to melt it. With leaded solder you can easily heat the parts being soldered to the 180-190C required to melt solder so it flows well around them completely. With lead-free the parts need to be in the 300C+ range which is difficult when you are using a normal iron. Really hot air or flow soldering is required. You end up with poor, dry joints and the loss of sound quality is audible IMHO.
   
  A note on upgrading existing soldering. Remove the old stuff first and don't mix solder types. Also use an old iron/bit for removal because it will get trashed pretty quick with cheap PCBs.


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## El_Doug

The best sounding solder will invariably be the one that you find easiest to flow into solid, perfect joints.  No amount of silver/palladium/voodoo will make a cold joint work better than a shiny, well-flowed connection.


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## Lil' Knight

Quote: 





fallenangel said:


> Use eutectic solder like 63/37.  Personally, I'm a huge fan of Cardas Quad solder, melts at low temperatures, stays liquid as long as you need and has enough flux to make good joints every time easily.


 

 X^n for Cardas Quad. Cheap but works like charm. I tried some WBT and Mundorf Silver/Gold solder, they are both great but don't do anything better than the Cardas.


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## Rdr. Seraphim

Maybe some folks eyes would roll, not mine. One of the pleasures of the Merlin's is Bobby provides upgrades throughout the life of the speaker. I purchased TSM-MX and over the course of a their seven year life had them updated twice at minimal cost. They continue to be very highly regarded. When I move back to a big rig, the VSM's will be contenders up front. 
   
  Back to the solder thingy, the difference with the MXe update (RoHS compliant) was significant in my system. I've used Kestor (in the late 60's and early 70's for my Dynaco and HK kits), Cardas, WBT, Mundorf (more recently), RS. The Cardas flows the best, I think.
   
  Quote: 





davederek said:


> when Merlin Music Systems was forced to go to lead free solder to comply with EU regulations, they unexpectedly found that it took their speakers to a higher level of performance. i'll bet that this type of talk will make some roll their eyes.  some folks hear no differences amongst cables while others hear differences ranging from subtle to significant. i think you'll find the same with solder.


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## Uncle Erik

I agree that the point of solder is to make a permanent, physical connection. I've experimented with the boutique stuff, but nothing flows as well as 60/40. I don't like the higher temperatures, either. It's too easy to damage components unless you do a lot of heatsinking, which is a pain. 60/40 lets you get in and knock off a clean joint faster, with less heating.

An excellent joint will perform better than a boutique cold solder.


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## sml1226

The only reason for ever using anything special is if you have an all silver setup (wire and connectors), silver solder will help keep the uniformity of it all (forget what I read exactly, but silver will oxidize if not treated or done properly unlike gold, so it may be a concern to some applications, other than that, anything works as long as it's not resulting in a weak cold-joint. 
   
  I've always used Radio Shack 60/40, but then again, I don't have that great of a selection without special ordering everything. I may try something different with my next setup as the spool of it I got this last time has terrible flux.
   
  If you live somewhere that demands everything be RoHS though, you're kinda stuck with the harder to work with stuff.


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## Lil' Knight

Quote: 





sml1226 said:


> The only reason for ever using anything special is if you have an all silver setup (wire and connectors), silver solder will help keep the uniformity of it all


 
  That would make more sense if you could find a PCB maker that can offer silver traces :~)


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## sml1226

Quote: 





lil' knight said:


> Quote:
> 
> 
> 
> ...


 

 Well yeah... I guess that only applies to cables. But if you can get a silver clad board, you _could_ do a PCB in silver 
	

	
	
		
		

		
			





 
  (You'd waste a ton of silver through the etching process. But... you would have a silver PCB)


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## FallenAngel

Then you'd shoot yourself for not going point-to-point


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## mojo

Quote: 





> Originally Posted by *Rdr. Seraphim* /img/forum/go_quote.gif
> 
> Back to the solder thingy, the difference with the MXe update (RoHS compliant) was significant in my system.


 

 The problem I have with that sort of thing is that there is no way to compare before and after directly since you have to send the speakers off to be modified. With cables although I have not got around to double blind testing I have used one type for left and another for right stereo and can hear the difference. I'm not saying that solder in speakers doesn't make a difference, just that the amount and nature of it is hard to determine without direct comparison.
   
  As an experiment if I can find some lead-free solder I will try to compare directly. It is entirely possible I am prejudiced against it because of the difficulty I have have working with it (I used to do electronics repairs and they got a lot harder when RoHS came in).
   
  For PCBs one trick people used to use before PCBs were coated was to put a thin layer of solder all along the traces. Apparently it made a measurable difference in radio equipment (reception rather than audio quality presumably).


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## holland

Quote: 





fallenangel said:


> Then you'd shoot yourself for not going point-to-point


 


  but you'd need component leads that are silver too. 
   
  I actually like Radio Shack solder, like Uncle Erik.  I currently use Kester, as I have about 10 rolls of it.


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## FallenAngel

I've got the following on my table:
  RadioShack 60/40
  Kester 60/40
  Kester 63/37
  Cardas Quad
   
  Those are listed in reverse preference order.


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## tangent

Quote: 





lil' knight said:


> That would make more sense if you could find a PCB maker that can offer silver traces :~)


 

ExpressPCB's RoHS process uses 99% silver. It's still copper underneath, but it may make sense to use silver-bearing solder like the common 62-36-2 eutectic blend for such boards.


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## Avro_Arrow

Tangent speaks the truth.
  In industrial process, the boards have very thin copper
  on them before they are etched. Saves on copper and time.
  Then they are plated back up to whatever thickness is required.
  They can be plated in any coating the customer requires; tin,
  silver bearing tin, silver, gold, unobtainium (if you can afford it)
  or whatever else they have up their sleeve.
  Other than the copper layer, most of the more exotic stuff is
  plated on after the solder mask is applied so only the exposed
  pads are plated with silver, gold or unobtainium.


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## MacT

olso use cardas solder, never had any problems with it. Totally unaudible


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## FishHead




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## laughingbuddha

I know this is an old thread but jewellers solder and solder paste seems to have the higher silver content they reckon your average silver solder paste has 5% solder content


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## John F Hendry

I have found what I think is the best non-leaded solder as it's almost as easy to work with as leaded solder. It's  "blended" and made by Sparkfun and is 96% tin, 3.0% silver, 0.5% copper, and 0.15 antimony. Best silver bearing solder I ever used. I'm not much of an electronics buff compared to the real deal but I do need to solder something once in a while and this solder is GREAT stuff!


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## tangent

Yes, Sparkfun, legendary house of metallurgy. 
	

	
	
		
		

		
			




  
 This is just another of a great number of lead-free solders. One that subs in toxic antimony for toxic lead, by the way.
  
 I find it odd that the product page doesn't say whether the alloy is eutectic. Also, it mentions water-soluble flux as though it is purely a virtue, when in fact it's a warning sign: you _must_ clean that sort of flux off your boards, because it is caustic.
  
 (Reminds me of the "triple organic" sign I passed on the road the other day. Ooooo, that _must_ be better than just _double_ organic!)


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## wakibaki

Every industrial establishment that used 63/37 multicore eutectic that has been forced to abandon it did so reluctantly, because anything else is harder to use, or more expensive, or both.

The pins on modern devices are coated with such diverse metals that it is nigh on impossible to pick a flavour of solder that can be guaranteed to be long-term compatible with all. As long as the solder wets, your luck's in, because long-term means years or decades. Unless you're planning on stereo in orbit.

If you've got time to worry about this, you've got too little to think about.


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## GoldenGate

This is a useful thread, to which i'll bookmark it for later reference. I love the ideas that are swimming in my head right now, coming up with options for projects i want to tackle.


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## GreenBow

I just started looking at this.
  
 I decided plump for CARDAS QUAD with 2% silver. I googled, and searched on ebay. They show a reel of the stuff and then some on a plastic bag. I mean, how are we supposed to know if the stuff they send is what they say.
  
 I have one tiny job to do.


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## MisterX

The Cardas Quad Eutectic melts at 370° and the flux has a rather distinctive smell.
 Could also check to see if the retailer is listed on the Cardas site as a distributor.


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## Metalsmith

The best connection is a solid mechanical connection, in a proper joint solder should be seen more as a glue and sealant to maintain said mechanical connection and not as a conductor. 

Also, I don't see any reason to go with exotic solder brands, you're paying mostly for the name. With research you will find the chemical makeup of the exotics is almost identical to a leadless Kester as it is silver bearing as well. But any "silver" or leadless will require temperatures of or near 400 degrees C or 750 degrees F for proper flow.


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## N0BOX

These 96.5% Tin, 3.0% Silver, 0.5% Copper solders are referred to as "SAC305".  I have the version Adafruit sells, though I've bought a bunch of random stuff from Sparkfun, too.  
	

	
	
		
		

		
		
	


	




  I don't have any issues getting this SAC305 RoHS solder to flow, but I do have a Hakko soldering station (FX-888).  I get good results with the temp set to 270C (I'm not sure how accurate the temp is, though, since I've never had the opportunity to calibrate it).
  
 I'll have to look up this Cardas Quad, though.  The stuff I have ends up corroding everything if I don't clean it with 90% isopropyl when I'm finished.  It claims to be a 'no clean' (rosin core) solder, but I've had conductive crystals form between headers and the pins of nearby ICs on breakout boards and everything I soldered together when I first started looks 'crusty'... sort of like a white rust, sometimes with normal rust mixed in.


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## MisterX

Typically the white stuff is from the "activator" in the flux.
  
 https://en.wikipedia.org/wiki/Flux_%28metallurgy%29


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## johnjen

No one has any experience with 'Wonder Solder' from TRT?

It is what I have been using since the 70's when I first ran across it.
I use it for all my audio related solder jobs.

http://www.partsconnexion.com/solder_trt.html

Flows well, is nice and shiny and comes in 2 sizes.
Also pay attention to the temperature as it tends to help burn off the flux.

JJ


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## FallenAngel

johnjen said:


> No one has any experience with 'Wonder Solder' from TRT?
> 
> It is what I have been using since the 70's when I first ran across it.
> I use it for all my audio related solder jobs.
> ...


 
  
 Yep, tried it. Easy to work with and works well.
  
 Honestly, after some years of experience, 63/37 works very well when you know what you're doing. I don' remember the last time I had a cold joint or any other issue using it.


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## FallenAngel

Question for the older guys: have you seen low melting point solder melt and not stick to the materials? I remember using some Cardas solder flowing across larger connectors (think Cardas RCAs) and then breaking off as if it never stuck. That's one of the reasons I use 63/37. Both materials should be hot enough to stick.


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## MisterX

I have seen that with the Cardas rhodium plated connectors but those are a pain regardless of the solder.


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## GreenBow

misterx said:


> The Cardas Quad Eutectic melts at 370° and the flux has a rather distinctive smell.
> Could also check to see if the retailer is listed on the Cardas site as a distributor.


 
  


metalsmith said:


> The best connection is a solid mechanical connection, in a proper joint solder should be seen more as a glue and sealant to maintain said mechanical connection and not as a conductor.
> 
> Also, I don't see any reason to go with exotic solder brands, you're paying mostly for the name. With research you will find the chemical makeup of the exotics is almost identical to a leadless Kester as it is silver bearing as well. But any "silver" or leadless will require temperatures of or near 400 degrees C or 750 degrees F for proper flow.


 
  


n0box said:


> These 96.5% Tin, 3.0% Silver, 0.5% Copper solders are referred to as "SAC305".  I have the version Adafruit sells, though I've bought a bunch of random stuff from Sparkfun, too.
> 
> 
> 
> ...


 
  
 Thank you for these replies. I just discovered what the temp is that my iron works at; 390'C. It is an Antex XS 25, http://www.antex.co.uk/soldering/precision-range-soldering-irons/xs25/
  
 It is an excellent iron with bog-standard solder.
  
 Anyway I have been rethinking the job I was going to do. My intention was to open some speakers of mine, the Q Acoustics BT3. They are power speakers and connected by a length of cable. I relaced this cheap black cable with some Chord Clearway and saw the improvement. 
  
 I was also thinking that the cabling inside either the master or the slave speaker, was cheap cable. Anyway on further thinking I guess opening the speakers would void warranty. Therefor I can't do anything until I find out. Even so though I wonder if they are soldered at all. They may use connectors.
  
 I would need to replace cable from amp to speaker, inside the powered speaker. Also the cable from amp to sockets out for the slave speaker. The slave speaker maybe the cabling too.
  
 I guess I need to contact Q Acoustics, and look for repair vidoes on youtube. Though I doubt there will be repair videos as there isn't much on these speakers on youtube.


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## Cidious

I use WBT 4% 0.8mm silver for all my serious projects. For testing and some smaller work I have some simple Chinese 0.6mm flux core solder which is actually not bad I guess..


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## MrMojo1

I use Kester 44 63/37 .031 and .020.  I use the .031 for most projects but do use the .020 for SMD soldering.  For around $30 you can buy a 1 lb. spool!  That's enough for a long time if not a lifetime depending on how many projects you do.
  
 Based on high recommendations from many online, I bought some Cardas Quad Eutectic for my last audio project.  It was kind of expensive (~$27 for 100g) but it was nice to work with like people say.  My initial impressions are that it flows well and my joints were nice and shiny : )  I don't know if it makes the sonics better but it doesn't hurt ; )
  
 I have also heard Wonder solder is good but I have not tried it yet so I can't comment.


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## sceleratus

I have always used Multicore / Loc 0.5mm 5 core.    I get great results.  I learned to solder SMD using Dave Jones (EEVBLOG) 3 part tutorial.
 This is the solder Dave recommends.  SMD is not a problem.  I can't imagine that some exotic or solder with say Ag would make much sonic of a difference.
  
 My son had limited soldering experience.  After watching the tutorial, he's building a dense SMD differential preamp.


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## ShinAyasaki

Switched from WBT 4% to Cardas Quad Eutectic because of the cheaper price 
	

	
	
		
		

		
		
	


	




 Actually It not too bad comparing with the WBT, except the smell of lead is strong with this one.


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## FallenAngel

shinayasaki said:


> Switched from WBT 4% to Cardas Quad Eutectic because of the cheaper price
> 
> 
> Actually It not too bad comparing with the WBT, except the smell of lead is strong with this one.




That's not lead


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## tangent

fallenangel said:


> > Originally Posted by *ShinAyasaki*
> >
> >
> >
> ...


 
  
 ...or if it is, I want to know how you got the solder to 1,749°C.


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## UnknownAX

tangent said:


> ...or if it is, I want to know how you got the solder to 1,749°C.



Not implying that what he smelled was lead but sure enough, soldering fumes do contain lead. At 400°C the lead concentration of the air around the tip would theoretically be around 1.9x10^-8 mol/m3. Much of that will bond to the fumes so at worst you could have 4ug of lead in 1 cubic meter of fumes...


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## ShinAyasaki

The Cardas Quad Eutetic contains lead, and WBT Silver Solder doesn't (http://www.musicdirect.com/p-7735-wbt-silver-solder-lead-free-42g-09mm-dia.aspx)
  


 And the smell of the WBT silver solder is much better than the Cardas, so I guess the difference is because of *the-amount-of-lead-was-contained* in the Cardas solder.
 But of course, the ingredients of the WBT solder and the Cardas one are much different, so maybe it's not about lead but the other thing, who knows?


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## b0bb

misterx said:


> I have seen that with the Cardas rhodium plated connectors but those are a pain regardless of the solder.


 
  
  


fallenangel said:


> Question for the older guys: have you seen low melting point solder melt and not stick to the materials? I remember using some Cardas solder flowing across larger connectors (think Cardas RCAs) and then breaking off as if it never stuck. That's one of the reasons I use 63/37. Both materials should be hot enough to stick.


 
  
 The Cardas RCA connectors have a lot of metal in them, I pre-heat mine with a hot air wand to about 240degF
  
 Flux is required to get the solder to wet the Rhodium plated connectors, I apply it and use a big tip to do the soldering especially for the ground connection.
 The solder flows nicely and the connection is very strong (cannot pull it apart using pliers)


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## EtyDave

I'm a big fan of Kester 63/37.  I mostly use 0.20" and 0.025" but occasionally use smaller for SMT work and larger if I'm soldering larger joints.


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## Rei87

I would to first state that I have absolutely no experience working with solders, or soldering for that matter. What I do have, is a little bit of experience playing around with the use of different solder in the upgrade cables that I purchase. I have personally sent my cables to be reterminated, mutiple times, using a different solder each time, and using fresh parts (I dont reuse the old parts). 

 So I would just like to make a strong statement in that solders do make a large difference in altering the sonic characteristic of the cable. I've tried oyaide audio grade solder, wbt and mundorf supreme silver gold. My personal take would be that mundorf provides the best sonic characteristics, with tighter lows and sharper highs that extends slightly higher. It is, an extremely revealing solder for lack of a better description. However it does come at a cost, as it is, according to those who have worked on my cables, a b**** to work with, and prohibitively expensive. 

 So solder does make a difference. But is it worth it? Prehaps yes, and maybe not. Its a balance of how far you wish to push your audio game, and how deep your wallet (or energy spent testing) extends.


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## Jonathan40

I use Kester 60/40, I believe. It's the "industry standard" as far as I know. I like a nice thin string of it for more control of solder volume.


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## melen1717

I've been using either Cardas Quad or Kester 60/40 for quite a while. Both flow nice and smooth even though Cardas does need a little more heat but it's not a big deal.


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