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  3. 161353-98013

Pass Labs x250.8 vs tube amps

I have a beautiful system. Lumin X1 > BAT Rex 2 pre > Pass Labs x250.8> Sound Labs M545 (ESL) in a tiny room (9x 11 ft).  This system has the most glorious SQ: smooth, detailed and powerful , along with great bass. I would say this sound equals or betters any ultra high end system. HOWEVER, I have a problem. My system takes 6 hours of music playing to sound this good. I had X250.5 and I had the same issue. Leaving it on idle overnight doesn’t solve the problem. It is 15 W class A, so it generates quite a bit of heat, and yet I have to still play music. Because my room is small, I don’t crank up too much- maybe this is the problem, but the temperature doesn’t complete stabilize for 5-6 hours. The top reaches 107 deg in 2 hours, but the front plate doesn’t reach 107 until the 6 th hr when it starts to sound glorious. I have never had a tube amp and I am wondering if I can reach that thermal equilibrium and the glorious SQ faster with a tube amp? I worried about the heat generation with a tube amp in this small room, but X250.8 generates 450 W just idling. This is no worse than tube amps like Audio Research 150 Se, which I demo’d and was impressed by. BTW, I need power in the amp because of the esl speakers.
What do you all think?

128x128chungjh
richmos
124 posts
 
Since you have the BAT Rex pre, maybe you should consider a BAT power amp like the VK 255se. Yes it's class AB but it has plenty of power for your panels. I have Apogee ribbons running on a BAT VK 42se pre and the BAT VK 250 amp. Great balanced combo.
richmos
124 posts
 
But to add to your post...really no warm up time required.
zavato's avatar
zavato
1,403 posts
 
@ chungjh 

the main switch on the back is always left on; the switch on the front is turned off after a listening session 
oldschool1948's avatar
oldschool1948
502 posts
 
@OP. My listening room is 13x12x8.  I have a PS Audio BHK250, which is a hybrid class A amp with a tube input stage and SS output stage.  My speakers are 89db Tannoy DC8Ti speakers.  It pushes them with ease.  I confident it will push your speakers with ease as well.  

When turned off with the remote, the BHK250 goes into standby mode where the SS circuits stay charged.  I give the tubes about 45 minutes to warm up before doing any critical listening.  It is a great amp.

+1 on the LTA ZTOL40.  I auditioned it for about a week.  It is a wonderful sounding amp.  I believe it will also push your speakers with ease. It tubes last between 5000 and 10000 hours.

I settled on the BHK250 because it sounded better with my PS Audio BHK preamp and DSD DAC.

Both PS Audio and LTA have 30 auditions and no questions asked return policies.  You might want to give them a try.
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toug27
8 posts
 
I own a Ref150 SE, it is at its best in 35-40 minutes but I must run an AC unit 12 months a year to be able to stay in the room ! LG 12MBH mini-split with low ambient kit for winter months, use it with Magico V3 ( not the easiest speaker to drive) never used it with ESL though... excellent sounding amp IMO
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