Bias for Jolida 502 P Amplifier

I called Jolida the other day wondering about why my 502P has 3 screw holes on the sides with no screws. The guy I talked to (not Jarred forgot to ask the name) said those are for the tube cover (didn't know one was available) anyway while talking I asked him about using KT 120's and he said he didn't care for the sound because he found them a bit bright but that the KT150's were really sounding nice (if one could afford them...)

My amp came with the Tungsol 6550 and it's sounding just wonderful as it settles in. Really liking the 3d solid soundstage and great bass. Lush but detailed at the same time. The proverbial discovering all sorts of new things in well known recordings taking place frequently . Paired with my Mapletree preamp it seems an exceptional synergistic combination.

You all don't know how much I worried about going from a very powerful SS amp (CJ MF2300A) to a tube amp a quarter of the power, particularly with my Magneplanar 1.7's. I worried for nothing.

When I talked to the people at Jolida about the 120s a while back (almost 2 years), they hadn't tried them, but assured me 120s wouldn't melt the amp. That, plus the good reviews, made me try them. I also liked the 6550s that came stock, and a set of Sovtek kt88s I bought (cheap), so I have all those for backup or whimsy. Psvane 120s do look cool, but since I've seen 150s for about 300 bucks (Ebay) and I assume they also won't melt the amp, maybe I'll try those when my 120s finally croak. Maybe we can start a tube exchange club...loan me some 150s...somebody...

Hi Ejman

I have the tube cover/cage for the Jolida JD-502P and it is an interesting one. If I could post a picture here I would. I didn't see it on the net when I did a quick image search right now. Sometimes I equate the cage/cover to the Darth Vader helmet. It covers a lot but does allow for ventilation from the top. I don't think the tube cover would fit with the Tung Sol KT-150s in place. It barely covers the amp when the Tung Sol KT-120s are installed. There are actually 4 screw holes. 2 on each side.

Instead of a stock tube cage, I'm thinking of making a small prison fence replica someday...little guard towers with tiny barbed wire around my tubes. Impractical but cute...I might be able to score something from a prison doll house company.

I see where you are going Wolf - with a cute little sign - "You are now entering Stalag JD 502 P..."