Another recommendation of the Dennis Had Inspire products. For much less cost you can acquire a used Fire Bottle amplifier and an Inspire preamplifier. All Dennis Had products are each hand wired and soldered. It’s the best of the best way to design and produce any audio product.
10-12 watts of power is far more than you need to operate your Heresy’s. Check out the audio forum audioaficionado.org for nearly 800 pages of comments from Dennis Had’s Inspire product owners.