I've got one and there is little info available. There are some Harmony Central reviews out there if you do a Google search. Also the Rocket 440 is a close relative and some info related to that is relevant to the the 44.
I think they were produced around the late 90s to early 2000s.
I love mine, they are loud and sit in the band mix well but also sound good at low volume. It easily keeps up with my bandmate's Marshall JVM 410 and 4x12 box - in fact I think it pulls a better sound than his rig. The cleans are very good and reasonably Fendery, but you also get two foot switchable distortion sounds as well - regular overdrive (sort of a fat singing Mark I sound) and contour which applies the scooped V Boogie EQ tone to the regular overdrive tone - this gives a more modern Metal tone - or an over the top sort of lead sound. They all sound great. In fact you can get nearly any classic tone with this amp. Shared EQ is not too much of hindrance IMO. I can get great cleans and killer dirt all on the same EQ settings. The amp responds well to distortion pedals too - I've used a Tubescreamer clone, an EHX Double Muff Fuzz and a Boss DS-1 in the front all with good results.
Silent speaker option is cool for recording or headphones. Reverb is spring but solid state driven and a little weak though adequate. The FX loop is a parallel type so you set your effects to 100% wet and then mix it in via a knob at the back of the amp - I actually like this arrangement but as you turn up the amp you have to adjust the mix knob.
There is also a seller on eBay who sells full tube sets worldwide - made up of JJs and Valve Arts - at a good price. A full retube with these cost less than $100US. The amp only weighs about 20kgs and is about as small and portable as a 1x12 valve combo gets. When I got mine S/H there was an undisclosed problem from the seller and this was to do with some faulty component in the power supply circuit that was causing the amp to switch automatically between regular od and contour by itself. The problem was difficult for my tech to isolate as it was intermittent and took a lot of labour time to repair because of the PC board design. That was 12 months ago - no problems since except for an intermittent reverb which was due to slightly loose plugs on the input and/or output plugs on the amp's reverb circuit which I fixed myself pretty easily.
Enjoy it - it's a very cool and versatile amp. Not very well represented in the Mesa timeline though!
