To repair, rebuild, or toss?

If you want something right now and decide to go slow consider something like this inexpensive  (see link below) well reviewed 100-200 watt power amp that comes with a 5 year warranty.

It can also be returned within 15 days for a 5% fee (plus I assume return shipping).

If it hits the spot then two can be use as mono blocks if you feel the need for even more power.

The Marantz you are using as a preamp is also well reviewed (even for 2 channel), but if you don't need or use the other functions then research preamps.

https://www.schiit.com/products/vidar-2f

DeKay

I concur with jl35 and lanx0003.  Time to move onward.  Perhaps fix and flip as a option B.  Audiogon has lots of fine, lightly used amps for sale....check out their listings!  Good Luck!

I think it is a good summary about RB 1080 By John A.: https://www.stereophile.com/content/rotel-rb-1080-power-amplifier-measurements

You also might be surprised how much you can sell it for on ebay...I’ve sold a few problematic or not working pieces and was surprised at the offers...probably guys who can fix it themselves and make a profit...my preference for the Vidar and Khartago over your Rotel is based on having owned all three...and I like Rotel, have had a RMB-1095 amp in my home theater for 20 years...

@lanx0003 

Unfortunately, compromises in tonal balance and subtlety are sometimes encumbered as well, and the resulting tonal inaccuracies are often flaunted as a distinctive "character."   ~ Stereophile

Your quote seems to have been taken from the same Stereophile article referenced by @westcoastaudiophile .  It is immediately followed by

No such compromise was evident in the Rotel RB 1080.

Does this change your conclusion from not worth it to worth it?