Jadis JA-80: Tubes and speakers.

Having not heard your amp specifically generally speaking going to an EL34 tube from a KT-120 will give you a richer warmer sound. However it won't, nor would any tube change, rid you of the bloated mid-bass or lack of dynamics.


A higher sensitivity speaker that's easier to drive might do the trick and there are quite a few threads on that subject in the archives. A few notable brands would be Audio Note, Devore, and various horn speakers, Klipsch, Charney, Volti, and various others.

There are definitely a few Jadis fanboys on here, hopefully someone will chime in with more specific advice.

Did you try your speakers on the different impedance taps on the amp?   The EL34 tubes will give a richer and thicker midrange.  I am not a fan of the KT120 tubes as I feel they impart a bit of grainyness into the sound.  I would go with the Gold Lion KT77 tubes. 

Interesting that Jadis authorized the use of the KT120 in your amp, I would not have thought they would do that...
Nonetheless, I think the sound you are laying at the amps door is probably not the amps fault. As Jond stated above, it sounds like you have a classic mismatch of amp to speaker. So many folks just buy amps and plunk them down in front of their speakers without considering the all important synergy between the two. Unfortunately, this hobby doesn’t reward mismatches...and you are experiencing an amp/ speaker mismatch, imho. I guess you didn’t have the opportunity or desire to listen to this pairing before acquiring the Jadis.

Change the preamp.  JPL is like chocolate syrup.

Thanks for all the responses. rhljaz, I did try another preamp, the Luxman C900u. To my ears The JA80 sounded better with the JPL.
About speaker synergy, I also tried another modern speaker, the results were somewhat better but not what I was looking for. I will continue to experiment. 
Thanks. 

One last note to put the record straight. it turns out the problem I had with the Jadis was just tube matching. After measuring the tubes (KT-120) and matching them properly, it now works perfectly: no problem of bloated bass or speakers matching. It just sounds marvellous. Again, thanks for all the responses.     

Hi
Yeah I bought a  Defy with stock 6550's, and traded to kt90's, and  now running kt80;s,,i  will go kt150;s early next year.
for the 12AU7 section, dump the AU's and get E80CC.s does not matter which brand, all sound eactly same,,although i *think* the Valvo's might be a  tad superior, not by much, The E80's blow away even the Holy Grail Tele's.
Note the Jadis web siteshows the JA80's with ~~~KT150's~~~ which is a  confirm i will dump the 88's for the 150's. although i lsiten on low volume i am looking to get every sonic tweet in my system for the classical muisc i listen to.
= well worth the extra $800 for the 12 tubes.
Go with 150's. o
once you install the E80's, , it really makes all the dif , to where it really does not matter which brand of AX you run..although again I *think* i hear the Tele's a  tad superior to GE's, Siemens, but again not by much.
The critical tube in a  amp is the AU section, as noted by another member ina  recent post.
I am very surprised few audiophiles have not caught on the the E80 as a  direct replacement for the crappy 12AU7. Even my Tele AU sounds like garbage next to any  branded E80CC. 
man that JA80 sure looks sharp, on speakers, go 
SEAS Thors, with all M SGO caps, ask Madisound to upgrade xovers with all M 
 and as a  second set of speakers, have madisound build the SB Acoustics  again with all M SGO caps. 
Both speakers will match the JA80's super high fidelity. 

  http://www.jadis-electronics.com/en/ja80-mkii-21.php

@mozartfan Don’t get confused that the JA80 and the JA80Mk2 are the same amp! They are not. The JA80Mk2 is designed for the KT150 tube..the original JA80 is not. Same applies for your Defy7. The Defy 7 is NOT designed to utilize the KT150 tube. Check with Jadis first before trying the KT150, otherwise a blown transformer may be the result.
I have posted on several forums that swapping in KT150’s into amps that are not designed for this tube is asking for trouble...seems like the word is not spreading!

Jadis pairs really well with Magico.