Differences between Link 1, 2 and 3 DACs?

Well I plan on using the Link DAC with 2 different sources, so I will need to run optical to the DIP and coax out, then into the Link, as well as optical straight into the Link from my other source.

I hope going from optical to DIP to coax and into the Link won't hurt the signal... too much.

Yes consider the inputs/outputs of the Monarchy. I don't think it has an AES/EBU output, whereas the Audio Alchemy DTI Pro (32) has one (and I've found that the Link Dac does ALWAYS benefit from jitter reduction). But with my Link Dac II, I found that an AES from transport into the DTI Pro, and then a Canare Digiflex RCA cable from the Pro into the Link sounded good. Sometimes the digital cable into the jitter device is more important than the one OUT of the jitter device (very odd but true). In most cases optical does not sound good ever (compared to any coax) but there may be exceptions. In any case I agree with the other advice -- try to just find a Nelson Link used, since it's the easiest/cheapest way to get the whole package that does have an AES/EBU input.

I have MSB Link DAC II and I have MSB Link DAC III !!!!
Basicaly thay arethe same ??? But not realy. Sond is quite similar but I prefer DAC III definitely. Monolith suplly is needed !!!! If you have dejiter than find used MPS, it will make DAC sound much better. Dan take next step and upgrade MSB DAC with better parts inside. There are quite a few to swop that will make huge improvement in sound !!!! Just go for it !!! Use the Linear Tehnology and Analog Devices .