I have owned my IRD-Audio MB-100 mono amps for about a year and felt there performance/value was unbeatable until I received by Khartago amplifiers. Both amps are built to high standards, but I would rate the Khartago as having more quality parts than the MB-100. The Khartago comes with cool blue heatsinks, WBT speaker connections, and Gronberg internal wiring.
Right out of the box with no break-in the Khartago outclassed the MB-100s by offering a more refined and better presence to the music. The soundstage had greater depth, better detailing and dynamics. The stage was less forward and had a warm perspective. These are my intial impressions right out of the box. If anyone were to ask me if the Khartago is worth the additional $212.00 over the MB-100s, I would say without a question! 6moons reviewed the MB-100s awhile back and on a scale of 1-10 gave the MB-100s a 6.5. On that same scale compared to the amps the reviewer was using, I'd give the Khartago an 7.5-8.0. And would add that diminishing returns seriously kick in after the $750 Khartago.