What has been your costliest mistake in this hobby?


For example :I recently learned a hard lesson- I accidentally ran voltage thru my $3000 MC cartridge (kiseki purple heart).  I have a TT with 5 prong connector and a phono cable with a 5 prong connector.  I accidentally swapped where they plugged into and ran electric thru the tonearm into the cartridge.  It was a stupid - not thinking- hasty mistake. When I corrected the problem the cartridge was fried.  An avalanche of four letter words followed!

So what has been your biggest and/or costliest mistake?
polkalover
costliest mistake in this hobby?  it's "Starting"...according to my bank account
Well years ago I had a fight with my exwife I came home to find my audio system destroyed and thrown out side only about a grand. I have bought used equipment that was no good about 600 and a nice preamp that listed for 6000 new,that I got cheap like 500 of course it lasted about 4 months .Hey it's only money.

I buy albums off of Discogs and didn’t notice that this one album was warped. Put it on my turntable and my JICO (Shure) VN5xMR stylus snapped like a dry twig. I was crestfallen....





@tinear124. I’ve got one that is similar. I was replacing a blown woofer in a set of “expensive” speakers. Removed without issue with a powered screwdriver... then upon reinstalling, the screwdriver slipped and yep... straight through the woofer. There have been a few others, mostly along the lines of spending too much money on cables etc... but the screwdriver through the woofer stands out.