Jadis Defy 7: need advice

So how do I know if it's the 1st, 2nd, 3rd or 4th version? Which are the recognizable signs for each one of these versions?

Thank you.

I think, other than relying on your seller's honesty, you could get the serial number and ask Jadis via their European website, they take a little while but generally will respond to an inquiry like that. Avguygeorge is right about servicing, although my recollection from an old post is that you may live in Europe, where the repair services may be better than in the US.

Avguygeorge, how would you describe the bass in the Mk IV? Did that improve in the last version or is it still a little full and fat? Your description of music vs. no music sounds to me like the difference between EL 34s and 6550s, which was one of my main complaints about the original Defy--the JA80s could use 6550s, EL 34s and KT88s with no need to readjust the amp; not so with the Defy. Did they change that by the Mk IV, or did it still come stock with 6550s?

Have a Defy mk3 giving the juice to an older pair off watt/pups.......big, fat, poweful bass...but not super tight.The highs are not hot. Just had my amp retubed andtuned up by Jadis Guru Tech Da Hong Seeto in NY. Service is doable.....very reliable amp so far. Mk 3 and after is what you want. Bigger, better transformer. Mk3 transformer is SAME depth as outside transformers...earlier versions center one is smaller. Amp is Very gutsy and breathes life into my Quad esls as well as the watt/pups. For the money used mk3s sell for....a very fine value.
dan