Hello audiotom,
I just joined the HT3 club last week. What an incredible speaker Jim is building.
I had the pleasure of hearing the HT3 with 3 different amps, one of them being the Moscode.
The only preamp that was in the system was the Audio by Van Alstine Ultra SL hybrid. Please be open minded and do not judge this book by its cover or its price.
I have to tell you I have heard a lot of equipment over the last 5 years and have learned the hard lesson that higher price does not always mean higher performance.
The AVA Ultra SL preamp is amazing. I have no affiliation with Frank Van Alstine but may be ordering one myself in the near future. I understand he just recently made changes in the tube circuit of this preamp. I have never heard any previous version of it but can tell you it is an incredible preamp. If you can deal with its plain looks and modest price tag you may have just what you are looking for.
I am running Vinnie (Red Wine Audio) Signature 70 monoblocks with my cd player direct to my HT3 and loving every minute of it. I did have a chance to use my Sig 70 monoblocks with the Ultra SL preamp and the additional gain (20 db I believe) was welcome and really allowed my Sig 70s to shine with the HT3 speakers.
I look forward to seeing what preamp you go with and the result. That is a very nice looking and more importantly sounding amp. Great choice on the speakers