Jadis Defy 7: need advice

I'll try to help a little, although I never have owned the Defy 7 (heard a few marks of it often, particularly the original).

1 and 2. The earliest versions of these amps were fairly "ripe" in the bass--i.e., they had lots of mid bass, and sound like they're putting out a lot of bass, but the deepest bass was overblown and fat, the opposite of tight bass. The later marks of the Defy may have improved the Defy in that area, but I don't know if you really can get "tight" bass from any Jadis products; my impression was that the later marks really were more like better refined versions of the original. For example, my Jadis JA80s are a far better amp than the original Defy in terms of refinement, but the Defy has more raw power. The later marks of the Defy started to approach, but never equalled in my view, the 80's refinement and subtle detail. I don't think you can categorize any Jadis amp as having bright highs; most are rolled off in that area, although the Defys using 6550 tubes might have a little glare in the 1-2khz area compared to those using KT88s or KT90s (the original version of the Defy could only use 6550s, which have decent bass response but are not as good in the midrange, in my view, as other tube types; I think later marks could be adapted for other tubes, but I'm not sure of this).

3. The Defy should have no trouble driving a speaker with the sensitivity and resistive load you mention; my JA80s easily drove Duntech Princesses, which are the same load you asked about, and the Defy has more grunt than my 80s.

4. As far as noise goes, don't expect it to be dead quiet like solid state, that won't happen. Tubes will always have some noise (and the Defy uses a lot of them), and older caps and resistors in some used units may intermittently make some spitting noises; I learned to listen through those noises, but they will be there and dependent on the condition of the amp and of the tubes in the unit.

Hopefully some owners of the Defys will speak up, but these were my impressions.

I owned the 7 mk 4 version for about 3 years. Only thing I know about 1,2,3 is what I read in Stereophile. That pretty well matches what rcprince says. I have since moved on to CJ 8xs (el34's)version. To me one is music;the other ain't. Even CJ 5's (triode/el34s) makes more music than Defy 7 mk4. Mids to die for with the right tubes. And, pray you don't need service from the factory or US distributor if you go Jadis.

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