How to physically move large heavy 100lb amplifiers easily (up and downstairs)

I agree with those that suggest a hand cart that's made to climb stairs. As suggested one or two additional straps are necessary to keep the item being transported in place. My hand cart has an additional extension that folds down increases the size of the platform from 18" wide x 6" long to 22" long. I've used this to move heavy amps and very large, heavy speakers up and down long flights of steps. No problem. It's surprising how you will use it for moving many other items at home etc.

My friend got a hernia from helping me move a Mark Levenson 336 up 2 flights of winding staircase.

Be wise hire a mover.

Best of luck!

Longer this thread goes, with all good suggestions, more correct geoffkait seems to have been. (Sell the amp, buy a Discman.)

https://www.collegehunkshaulingjunk.com/labor/

(no matter what they charge, it is worth it)

Dolly with padding and straps or duct tape. I don't know how any household does not have a dolly.

"A keg is a lot bigger and heavier than an amp, and we were able to carry one cross-country with two people just about any distance over just about any terrain."

After a long head-scratching period, one has to admit there are bragging rights in the disclosure above.