Hi,
There are few versions of the YBA Integre that were made over the years. On each of them as an added option was the famous DT version. Exactly the same as the basic version but with another C-core transformer. DT stand for for Dual Transformer. This gives the amp more punch, better dynamics and all around more control. The other options were a built in phono stage and remote control.
Beyond the first YBA integre produced he had also made minor modifications
to the circuit over the years. This can be found by a small Greek symbol right after the lettering Integre on the amp. First was the Alpha α, next the Sigma version Σ, and lastly the Delta Δ.
At the time of Alpha version the Integre started to use the YBA Gold badge on the front faceplate. Although some earlier Alpha versions still have just the lettered printing on the faceplate.
Another change, I believe during the Alpha, is an extra set of recessed banana speaker connectors next to the five way ones. These are to be hooked up if you wanted a softer more tube like sound.
Later on there was the YBA integre Intial meant to come in at a lower price point. This version only has one transformer and instead of six smoothing capacitors it only has four.
After this came the Passion Integre amps that were far more money and had more power.
Then the YBA owned, Taiwanese made, Audio Refinement brand emerged The Complete integrated amp was based on the Integre but coming in at a much lower price.
YBA is now owned by the Chinese company Shanling. Although Yves-Bernard Andre still is the chief designer and if not partial owner of the brand. All components are now made in China for the exception of their top of the line Signature gear which is still made in France.
Hope this helps!