Please help a new tube user!

Hi, I'm new in tubes!!!! Iwould like to help me someone with bias adjustment of the JADIS ORCHESTRA (EL-34).
Many thanks
john

don't forget - the new tubes will need burn-in.

To all who pitched in-- thank you for your help! I'm very excited about moving to tubes... like owning a vintage motorcycle; sure it requires some care, but that's all part of loving the experience. Thanks again! d

I've owned most of the big names in tube equipment and have the Jolida 502B in my bedroom system. Jolida has about the best price/performance ratio of any tube amp. That said the original chinese tubes sound BAD. When you get the unit if those are the tubes that come with it I would retube immediately if your budget permits. The KT-88's referenced above make a major improvement to the sound, especially in the bass. I have also retubed the small tubes with high quality NOS tubes and it does make a very noticable difference. I've been very happy with the NOS tubes from Kevin at Upscale Audio. A full set is rather expensive ($80-$120) but I do think it is worth it. Biasing is easy.

Sorry to have neglected your second question. Buy a multimeter, as you can do so much more than a voltmeter with it. A good one(and you don't need anything great) can be had reasonably(less than $100). Biasing a Jolida is simple. Not the easiest(like the CJ red LEDs), but really easy. There are connections on the topside of the amp for your meter. Simply make the connection(you measure and bias one tube at a time) for each of the four 6550s(replace them with JJ KT88 during your eventual retube), and measure. If it is out of range, adjust it into range. Child's play. In fact, I have a piece of literature from Jolida where they wanted to convey how easy it is. They took a bunch of women who work there(not sure why they needed to stress that), and set them up with an amp, a meter, and the Jolida instructions. None had a problem biasing an amp(so they say). You can also experiment with the bias; definitely changes the sound. Don't go light years away from the specs, but you may like the tube biased a hot or cold.

i agree with trelja. pull, box and carry the tubes into your local hifi shop and have them tested. if they're okay, put 'em back in and have a listen. while you're getting familiar with your new amp (and recovering from the purchase), do your output tube research, then buy. an added benefit of this stratgey is that it gives you the opportunity to fall in love with your new acquisition a couple of times--when you take delivery and start listening and later on when you retube (rather than consolidating the two events into one). that's what i did when i bought my current amps (used cj permier 12) and i'm happy i did it that way. in answer to your second question, i've been listening through tubes for about 5 years or so and have not needed any special or unusual tools to tinker with my amps or pre-amp. welcome to tubeland and enjoy.

Forget about changing the tubes until you evaluate the amp as it is. The first thing to do is to look at the tubes. See if there is a name on the glass. After that, set your system up, and LISTEN. Nothing wrong? Why change? I do recommend that if these are the original Chinese tubes in the amp, you replace them(at some point) with JJ(Tesla/Teslovak) KT88. The Chinese tubes seem to slow down the music, and muffle everything. To my ears, the Russian tubes do not have as nice a tone as the Czechoslovakian made tubes. But, so long as the tubes you get are OK(even if they ARE Chinese), they will do no harm. You can use the smaller tubes from Sovtek, JJ, Ei(best?), or the like. Next up is moving to a better power cord...

You could test the tubes, but I would also be inclined to re-tube if only for the peace-of-mind effect. Definitely talk to the manufacturer to get their take on what works best with their products based on actual experience. Be very careful to find matched tubes with the correct combined values for each channel. Doing the NOS thing can be iffy and expensive -- there are some really good new tubes available today. Good luck.

I would retube the unit. Try thetubestore.com fast friendly quick service large selection lots of tube info. I am also new to tubes and use cj equipment. I have had a couple of defective tubes; one burned out and the other was very noisey. So when to replacement was easy. I do not know anything about Jolida equipment you may want to write or call them. If they are anything like cj they will be more than happy to answer your questions.