Solder-less Connections
The concept of solder-less connections is an intriguing one, and possibly one that will save a lot of work for the casual hobbyist. Every so often the casual hobbyist or experimenter is encouraged to 'learn to solder' at some point. I have done some soldering, most recently soldering the audio input wires to a amplifier board of the TEA 2025 amplifier I use.
I see two problems with soldering: the first is the presence of noxious gases when soldering: one is asked not to breathe in these fumes. The second is the inconvenience of heating up the soldering iron and working with the soldering iron, solder and the component.
There have been some alternatives that have been available for some time. One is the crimped connection which I am familiar with in the line of my work. When working in the IT department of a company, part of my job was to crimp RJ-45 connectors for networks. Soldering would not have been practical in that situation. Many car audio installations use solder-less crimping connectors.
I plan to avoid using solder in all my audio projects. At present my laptop PC system is connected using solder-less connections.
Electrical Connectors
There is a a range of electrical connectors and standards listed in Wikipedia:
Euroblock
"Board to wire connectors" Ali Express
Nilabara Electronics (Sri Lanka)
The RJ-45 connector is on the left in blue. The other connectors are used for telephone lines.
No soldering is involved, and connection is done using a crimping tool ( not shown ).
Solder-less Connections terminal Blocks in Use
https://shopee.ph/Practical-6Points-Terminal-Block-Set-Screw-Terminal-Blocks-i.82268435.3841440362
Solder-less Concepts in use
Many of the connections used in Hi-Fi are in fact solder-less: RCA jacks, mini RCA stereo jacks, USB connectors. Many speaker wires are connected to the amplifier using solder-less connections with screw terminals or banana plugs.
Is it possible to use solder-less connections internally? There is an amplifier kit listed here that features solder-less connections in its construction. Many of the boards available for amplifiers feature on board connectors that can be simply plugged in using a suitable plug.
Here is a paper published on on solder-less connections
(Pan Pacific Electronics? Symposium)
www.circuitinsight.com/pdf/past_present_future_solderless_smta.pdf
https://www.researchgate.net/publication/7809381_Materials_science_Electronics_without_lead
Links
https://phys.org/news/2017-07-harmless-elements-toxic-electronics.html
Some solder less Projects
ECF -80 Valve amplifier on a breadboard. High Voltages.
http://www.r-type.org/static/bread.htm
https://runtimemicro.com/Construction/Permanent-Solderless-Breadboard-Projects
http://msx-elektronika.pl/en/screw-terminal-solderless-breadboard-plug-in-ark4
Partly Solder-less - the transistors could have been connected using solder-less connectors
https://tronicspro.com/diy-d718-stereo-amplifier-homemade/
A tube amp with screw terminals for the amplifier tube base
https://deathtube667tubeamps.com/se-dc-breadboard-amp
https://www.jensign.com/60dBLowNoiseAudioAmplifier/index.html
Wire Wrap technique used successfully for rapid prototyping without solder. Requires special tool.
https://runtimemicro.com/Construction/Permanent-Solderless-Breadboard-Projects