Gareth Magennis wrote:


This really annoying, but a good opportunity to learn something useful.

I have an old Urei Power Amp that needs its DPDT 10A speaker output relay
replacing.
It's annoying because the relay fitted has a totally non conventional pin
configuration, so the usual generic cheap replacement is going to involve
drilling holes in the PCB and isolating pads and using glue and stuff
because some solder pads will have to go etc.

So I thought about maybe using Solid State relays, which should be
physically smaller and lighter, and could be mounted in little patches of
available free space.


I've never seen a solid state relay in a Power Amp. Maybe there's a good
reason for that - AC transmission, Inductive loads, back emf etc.
A quick look at Farnell shows you don't generally get DPDT ones, so you need
2 for a stereo amp, and they are not that cheap.


Any experience welcome.


** Don't let the name fool you, SSRs are not replacements for regular relays.

SSRs use triacs or SCRs and are intended for AC supply switching and the like - where voltages are high and fixed and a discontinuity around zero is not a big problem.

Simply will not work with speakers.


..... Phil