A clarification and update: The MyRefs are monoblocks, so the cost for 2x units includes some circuitry that is replicated across both boards: The rectifiers, PSU filter caps, snubbers, chipamp bypass caps, speaker DC offset protection circuitry, speaker relay, opamp supply and regulator, etc. Together, the replicated circuitry accounts for about 75% or more of the board area of the MyRef. The advantage of this setup is that this gives very good channel separation and isolation between the two channels.
For more price-sensitive and space-constrained applications, I have designed and built another LM3886-based nested topology called the MiniRef 3886. This contains two channels on one board, and many of the expensive components are shared across *both* channels. This saves space as well as cost, and the MiniRef is a stereo board on one PCB which is about 25% larger than a single channel of a MyRef.
The current status of MiniRef is that the first prototype works and is under testing and evaluation for audible sonics. In simulation, it is comparable to a MyRef on most performance parameters, although the topology differs from the MyRef in several ways. Some minor tweaks may have to be done to fine-tune stability and/or sonics.
Those who want something that is proven and works/sounds great out of the box should stick with MyRef Rev C/E/FE monoblock kits. However, those who're willing to experiment and tweak a new design which is potentially comparable to a MyRef, but at a significantly lower cost for 2 channels, should consider the MiniRef 3886. The MiniRef also allows opamp rolling, so future opamp upgrades are possible. The MiniRef also shares about 90% or more of its parts with the MyRef, so there will not be any shortage or difficulty in obtaining most parts for the foreseeable future.
I have a few MiniRef bare boards as well as parts sets available - PM me if you're interested in prototyping/tweaking the MiniRef for use as a low-cost alternative audiophile-grade chipamp board.
