FirstWatt SIT-3 or Pass Labs XA25 for Avalon Indras?

In addition to suggestions above, if you still have interest in Pass design, look up reviews of the SIT 4, particularly a video of Steve Guttenberg (SG), a stereo unit, due for release in mono block --twice the power. SG suggests "notably more powerful sound than specs suggest". Of course there is only one way to find out. Enjoy the search.

I own both the XA25 and SIT3 but can’t add anything meaningful to the conversation because I don’t know your speakers.  My speakers are all 8 ohm and high sensitivity and I use multiple subs so low level listening is very enjoyable.   These are quality amps when system matched properly. 
 

@whiteknee "These are quality amps when system matched properly".

Exactly. And yet the OP keeps asking about the lower powered SIT-3, regardless. The more operative question would be has anyone heard SIT-3 paired with your 87db 4ohm Avalon speakers. I’d venture to guess most likely not as it would not be a recommended match and pairing. Proper amp-speaker matching makes a real difference.

ulul

I've never heard any First Watt amplifier, so I'm no help there.

I bought a "lower" power solid state amplifier earlier this year (a CODA S5.5), if you can find a dealer near you to demo one, I think it would be worth your while.

50WPC pure class A, more in A/B; 100 amp current delivery, and in my system (Aric Audio Motherlode XL driving: vintage Infinty RS Kappa 7s, Buchardt S400 MKIIs, Clayton Shaw Caladans, and Thiel CS 2.3s. It is stellar with each speaker, and the Infinitys and Thiels are not easy speakers to drive. I also do not listen at loud volumes, and love the presentation at "reasonable" listening levels

As you may know, CODA's Doug Dale and Eric Lauchli were with Nelson Pass at Threshold, until Nelson left to form Pass Labs and later First Watt.

Worth a listen if you have a dealer within driving distance of you.

avanti1960

SIT-3 at 8ohms delivers 18W not 8W (30W at 4ohms).