Sovtek 6550 - Can they really be THIS bad???

Rob, I'm so happy about the JOR not having a "real" transformer issue. That would be quite painful.

You read me 100% correct in my saying "loose" meaing what you thought it meant. My idiotic ramblings are so all over the place, it's a wonder anyone can understand me sometimes. It's easy to see how a loose transformer could really buzz. The biasing of the amp should not involve loosening the transformers whatsoever, only reading a few resistors, and adjusting the respective potentiometers until the voltages on those resistors falls into spec. Still, I'm sure it could have loosened any number of ways.

Good luck with that JOR, it's one of the finest sounding amps I have ever encountered, if not the finest.

Joe,
I need to make a correction. I think the stock tubes for my CAT JL-2 are 6922--and I haven't changed them.
You're still welcome to come over and have a listen of course.
Bob

Well, after spending a few more days trying certain things, and talking to a few people, I wanted to update things.

In my situation, the crux of the problem is NOT the Sovtek 6550. I wanted to clarify that I have been listening to them in my DA30, and while certainly no match for the JJ KT88, they still allow the Jadis sound to assert itself. I feel obligated to let everyone know that while they are not going to become my favorites, they are not the root cause of the poor sound I am experiencing.

I guess for many, sadly, they would not think anything was wrong with the DA60. However, I have become quite familiar with the Jadis magic, and this amp does not possess that. Amplifiers from other companies simply do not have it. Someone not familiar with it might not be able to tell, but I was. And, it is through no fault of the tubes. While a legitimate Jadis, I have discovered the amplifier has been modified by folks who have somehow bled what is special about a Jadis out of it. And, along the way, have done a lot of wrong to the amp, manifested in the way it works. This was in no way devulged to me by the seller, and the amp was listed in very good - excellent condition. I am not sure what my recourse is. But hey, caveat emptor, I bought a used component. Though I have purchased new Jadis products, as I said, there was no way I could swing $11,800 for this integrated. Worst case scenario is that I have found a person expert in Jadis, and has the ability to get the DA60 to where it should be. At which point, I can accurately determine how it compares to my JOR and DA30.

But, again, I feel it necessary to make sure I apologize to Sovtek in regards to their 6550 output tubes. They are NOWHERE as bad I initially inquired about,
Joe

Sorry to hear about your DA60 - if the seller knew that the amp had been modified - and how could they not unless they too bought it used?? - he/she certainly should have revealed this. Hope your Jadis expert can get it back to "stock" performance for you.

Holly

I own a pair of CJ premier8s, used them for a year with Sovtek (16 of them!) tubes with no problems except wear. I changed to Svetlana C about 6 months ago and sonic improvements were not subtle.

Now, I have a friend with a Jadis amp (Defy7 in this case) and he got the best sound from it testing and measuting all tubes and install them in sets of 4 at the clostest measuring rate, since the Jadis amp works (I understand) in quads (serial) and does not have the autobias feature of my CJ.

Hope this helps.

Fernando