John Curl's Blowtorch preamplifier part III

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Lead free solder is a poor substitute with higher melting temperature, worse flow, worse cleaning.
I am not interested to argue about this crap.
Hey, you made a statement of your opinion, I am just interested to know why you have such objection and make such a blanket statement.
Reality doesn't matter to Max. You're right that lead-free is objectively worse in pretty much every way except RoHS compliance.
Reality matters entirely, I asked the question of McH because his opinion does not accord with my experience.
Chris please grow up and quit the personal barbs at every opportunity, there was no justification for you jibe and I would appreciate your apology.

Lead free is not that bad though if you have a good oven. I use the Kester NXG1 paste.
.......which is Sn96.5/Ag3.0/Cu0.5.


Good iron, good solder wire and LF works fine for me.
Perhaps those who complain about LF are not practiced enough to use it correctly.
Yes, the Sn99.3/Cu0.7 solder that I use is quite different to use than lead-tin solders and it may take some practice to 'get the hang of it'.
Temperature, solder time, pre-tinning requirements are different but once mastered I find that this LF alloy produces solder joints equal if not better in wetting/tinning/appearance and strength to lead solders.


Dan.
 
I guess I'm late to the party, but I'll say I really like my TS100 soldering iron. With the cone tip that's not needle sharp nor excessively rounded (but impossible to order because it is name swapped with another tip and the reference images don't convey scale), I can solder to almost everything. Big cap pins going to ground planes without thermal relief still cause trouble though, for that I use the butane iron. You can increase power output with a 24V PSU but I haven't done that yet. I prefer 350C with 63/37 solder.

A lot of big looking bench irons aren't as powerful as the TS100. The power in combination with precise and fast temperature control makes it easy to use.
 
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Yes, and wire wrap. 😀
Last century it was common for 'consumer hi-fi' to use tinned copper solid core internal cables and wire wrap pins.
Under abuse/non ideal conditions (ie much dust, high humidity, seaside environment etc) I have found this WW method long term to be not totally reliable.
The solution was to apply liquid flux, heat and solder, even flux/solder/desolder/resolder to restore reliable connection BUT I found the application of solder changed the sound of such amplifiers AND according to the solder alloy used.


Dan.
 
If connection quality is your reason for using crimps then you should not use crimps that don't pass the pull test. The crimp connection should be stronger than the wire itself, IE the wire breaks, not the crimp. Typical plastic shrouded crimps can just be pulled apart with pliers. I haven't gotten hardware store type crimps to pass the pull test, would be interested to know if others have gotten good crimps on fast connectors with affordable tools.
 
Objectively or subjectively and why ?
Both. Strong bond, last a long time, no or minimum amphoteric metal. It was years ago, we spot weld several interconnects, sounds slightly better compared to 3 % Ag Cardas soldered but rather cumbersome to make, decided not worth the effort. We could not measure any difference.
... Under abuse/non ideal conditions (ie much dust, high humidity, seaside environment etc) I have found this WW method long term to be not totally reliable...
Some coating like varnish do help for use in slightly corrosive environment.
 
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Both. Strong bond, last a long time, no or minimum amphoteric metal. It was years ago, we spot weld several interconnects, sounds slightly better compared to 3 % Ag Cardas soldered but rather cumbersome to make, decided not worth the effort. We could not measure any difference.
'3% Ag Cardas' lead based or lead free ?.
How did you go about performing the spot welding on what kind of wires/connectors ?, ie can you give more details/pics please ?.

Some coating like varnish do help for use in slightly corrosive environment.
Yes, it's called conformal coating, standard equipment on IP rated gear, definately not standard on audio gear of the time.

Dan.
 
'3% Ag Cardas' lead based or lead free ?.
How did you go about performing the spot welding on what kind of wires/connectors ?, ie can you give more details/pics please ?...
I think it was lead base but I could be wrong, it was quite a while ago.
We used something like this but the electrodes were tungsten. Copper electrodes will stick to wires.
 

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Both. Strong bond, last a long time, no or minimum amphoteric metal. It was years ago, we spot weld several interconnects, sounds slightly better compared to 3 % Ag Cardas soldered but rather cumbersome to make, decided not worth the effort. We could not measure any difference.
So many things having a greater impact on the sound quality, in audio electronic !!!!
I found lead free solder boring to use and 60/40 faster and easier.

I do not know if the lead-free solder will allow us to live longer, but, for sure, the time spent on our workbench seems longer with it ;-)

Although many of us have been more exposed to soldering iron smokes than the man in the street, I think that what will kill us more surely at the end is ... life.
 
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