Jadis DA60

I used to own an Orchestra Reference, and currently have a DA30 and DA60. In my experience, in addition to being some of the most glorious sounding components, Jadis integrateds are as reliable as anything on the market. In fact, in my system, they've been flat out bulletproof. I've often heard Jadis transformers are warranteed for life, so if you bought the amp new, there should not be too much of an issue for you.

Since Jadis integrateds fuse each output tube, the statement of your technician doesn't seem especially plausible. In my JOR, I had a fully shorted KT90 output tube that caused absolutely no damage to the amp whatsoever. A bad tube would blow a fuse long before a transformer.

I realize this is not going to come across well, but my guess is that the problem is you. Do you have a load (loudspeakers) hooked up to the amplifier at all times? Running a tube amp without a load is a surefire way to blow the output transformers. The vast majority of tube amplifiers that have been built since day 1 have never had a problem with their transformers despite seeing a lot of bad tubes - look at all the vintage Dynacos, Fishers, Scotts, etc. that can be brought back to life even after decades of neglect.

Yoh,
Hmmm--Sounds like a faulty batch of output Trans poss'-- if you are doing everything right as Trelja states any fault arising from the Tubes will blow the 180R across the tube( you can see it large dark green one). I must admit not having heard of many output Trannies going south ,however Jadis Power ones set for 220v HGK market finding their way to Aust will hoof it with our 240/250 v surges.

Have you tried this Tech-- he poss could help in Sydney

joseph.barkoczy@audioconnection.com.au

Best,
DesW

I heard Treljas DA-60 and had to get one for myself. I thought of using EL-34s as it is my favorite output tube -until recently. I took Jim McShanes advice when retubing a 6550 amp . He said there is only one tube that I would like. It happened to be the Gold Lion Kt-88. I was never a KT-88 fan but he was very certain when I told him I wanted a forward midrange somewhat warm and of course euphonic sound.
I was extremely surprised by his accuracy it sounds great.
It is a very versatile amp. As Trelja says it doesn't seem to get unwound by anything.
Mine is rock steady. It is auto bias and so far has given me no problems. Even when accidently left on idle and despite screwing around with the input/pre tubes.

BTW Try 7613s for the 12AU7s and 5751s for 12AX7s. Personally I switch things around every so often. 7613s are all Heerlen Holland made Amperex tubes but usually labeled for computers they are quite expensive but truly different and truly better IMHO.
The 5751 story need not be repeated here but if you invest they are also expensive, some sound like garbage even if you pay for better tubes. Of note any blackplate will cost you more than a grey and 3 mica more than 2 mica.. It wouldn't hurt to try the Jan Sylvania/Phillips variety for $20. You will get the transparency thing I'm sure.
Last night I put in 2 Tungsram ecc82 and a 7613 in the center and left the Mullard ECC83s for the 12AX7s in place. It sounds great but tubes are a luxury and still and can cost you a lot of money for crap. Now prices are coming off slightly as the market is full of sellers not buyers. Soon they will be even lower but the supply of NOS is just about gone already.
Finally make sure you don't have a modded amp. There is some clown modding an amp that needs modding the least and ruins the sound.
Haven't clipped it so far and I like it loud. Keeping my fingers crossed though.

Thanks for your responses.

I naturally always have a load connected.

I myself have wondered why the fuse does not blow to protect the amp. The tech at the one Jadis dealer in Sydney said:

"It is true that there is never enough current to go through the valves to "burn out" the output transformer as such. In the instance of Jadis DA60 each valve is protected by a 200mA fuse, which means that if a current of more than 200mA going through, the fuse will blow.This is the theory. But in real life if one of the valve develops a flashover inside the envelop, it may not be high enough current to burn the fuse but the spike will cause a very high voltage back EMF on the primary of the transformer, which adds on the over 470 Volts already there, can and will puncture the thin layer of paper separating the layers of windings between the primary and the earthy potential of the secondary of the transformer."

Does that sound reasonable to anyone?

The transformers are not warrented for life, however Jadis in France did cut me good deal, but having said that they are still expensive.