Bias for Jolida 502 P Amplifier


Just got my new Jolida 502 P yesterday and I'm enjoying it a lot - great sound! (Thanks Wolf and Jedinite for your posts re the Jolida amps) I'm surprised at the amount of bass and slam I'm getting with my Magneplanar 1.7's In fact I'm thinking that for a lot of music I probably won't even turn on my HSU sub.

On setting the bias - how important are small variations? When I got the amp I checked with my multimeter and the amp was set at about 560 mv for all tubes. Moved the bias back to 500 mv per the manual but I'm not sure if it really matters all that much for these small changes? How critical is this?
128x128ejman
Wolf
In my opinion the kt120's sound much better in the 502p.The 120's are more extended top to bottom with with better separation and a fun energetic presentation .The Gold Lions have less extension top to bottom and seem just ever so slightly congested when compared to the 120's the GL just seem more laidback and relaxed. FYI I had the gold lions in for the last 6 months and the 120's for about a month now.
Man all this talk about the KT-120s makes me want to put them back in my Jolida 502P. That or check out the PSVane KT-120s. They are pretty looking. Anyway I've been enjoying the music in a nearfield set-up for the past couple of months with JJ KT88 Blue Glass tubes, JJ 5751 tubes and Mullard CV4024s.

I have to look through my notes. One tube enthusiast by me strongly preferred the solid plate Penta Labs KT88SC vs the Gold Lion KT88s. I think he liked them better all around and the Penta Labs KT88s had better reliability in his experience.
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.