It’s a good question. Since 2006-ish Sound Lab introduced new generation of extremely rugged, durable panels and with the newest super glues – basically the panels are extremely reliable. Many Quad owners must have repair work after few years because they are rather susceptible to breakdown (I mean no disrespect).
New Sound Lab panels especially since after 2012 really do not require repair – the insulation is excellent. Taken care of they will last for years and years – one of my pairs are 13 yrs and no problem. Should there be an accident and need repair, it is best to send back to Utah. They are all custom made, made by experienced family staff and hand crafted, not mass produced at all. Extremely easy to talk to and to receive support from Sound Lab.