I have a new M40, all others long gone.
Oh I forgot the Quatra (inca tech, stolen by Lescon), Oberon ( design again stolen and bodged by Relph), Sabre. Many pre-amps ID1P ,etc A design I did for AR stolen and made into the Magnum A Class and well a truly s Bodged up with cheap crap, many caught on fire. A speaker design for a company Mr. Kaufman owned. Inca Teck Dirk, and my fingers went into a few for others companies that they paid for nice companies
There is also a few 20W SECA amps built from kits by DIY audio/music lovers. And 1 50W SECA made by my friend James (RIP) I miss him, now owned by Mr. Charles C. James also whilst in hospital made a few cables I designed for him to hand make in his hospital bed.
The reason my designs got stolen is the same company that design the PCB layouts worked for me and the thieves and they sold them on see greed strikes again.
Now days I have my own CAD/CAM software and take great care on layout not to make it look like art but sound right. taking great care on track location, screening, mass of Cu, so not like the pretty box designs you see often.
So you inventors out there beware of people offering to help with money/marketing and other form of help, some are crooks, never trust a person who "say's you can trust me".
I was a fool I did trust them, never share 50% of you great ideas, listen to them wanting to be MD (beware) never allow them to add there friends to the directors list, never sale share to there friends, then hear a soft sob story later they need the money back but like a fool you allow them there 10% to keep. I did all this you must not.