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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
ozzy's avatar
ozzy
7,486 posts
 
chungjh,
Carver claims that his design makes the tubes run cooler and the tubes should last longer. I think his claim is something like 20 years. But, that is hard to believe.
Bob Carver has always been easy to contact, heck he even flew to my house when I was demoing his speakers. (I didn't like the speakers by the way).
The Lumin X1 with the new Leedh volume control direct to the amps is definatly the way to go.

ozzy
ozzy's avatar
ozzy
7,486 posts
 
And, by the way. Since you could sell your preamp, then get Critical Mass 1.0 footers for under the Lumin X1. I also have them under my Carver amps and Niagara 7000 power conditioner.
You will be amazed what they do for the image, frequency extensions, soundstage, etc.

ozzy
decooney
2,033 posts
 

As @decooney indicated, the heat is not my biggest issue. It is the time to warm up. My logic is that tube amps will reach the optimum temperature more quickly than Pass Labs or other SS. Tell me if I am wrong.

@chungjh
You are correct when referring to some of the higher end amps with massive transformers. Most of my tube amps   only take less than 1hr.  I was a 35-year solid state amp guy, back to mono tube amps now days. Today, 45 minutes of warmup, ready to go. I simply don’t have the extra time or patience to fire up my former solid state amps and let them run for 6 hours of pre-warming for a 1-2 hour listening session. Was not worth it, IMO.  

Some of the more modern output tube amp designs and tubes do not get overly hot. I can hold my hand directly on the transformers of my current Quicksilver Mono 120 tube amps for ten minutes straight. Warm, but never hot. The output tubes are warm but not scorching like my older tube amps were at times. Similar to Carver’s amp designs. Ask the designer-mfg-seller to put a laser heat gun on it and tell you what the transformer/tube temps are after 6hrs. Try the same with the Pass 250.8 at 1hr, 2hr, 6hrs and see what you get and when it sounds good to your ears.  If you go with tube amps, hang on to your Pass 250.8 if you can, its a lot of fun to rotate. 
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zavato's avatar
zavato
1,403 posts
 
I own an X250.8. I have had tube amps in the past- CJ and Rouge 

2 comments- my amp is fully warmed up in 1 hour. Next- having had tube amps for about a dozen years, with the X250.8, I do not miss the tubes at all 
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