Parasound JC1's vs. Sim Audio W10

The sorry facts regarding the JC-1 is that they don't sound good unless you have 1200 - 1400 hours of play time on them. I heard a pair last year and frankly was underwelmed to say the least. They had a total of about 200 hours.
I would hope they sound great after 1400 hours, but me ( living in Australia) I am not going buy something I don't like the sound of, on the promise that it will dramtically change after 60 -90 days. If there was a money back guarantee - perhaps. I checked with the dealer today and the amps still only have 300 hours on them and they much prefer the W-5's. They thought I was mad stating that the designer asks you to put 90 days straight for it to sound decent.
To me Parasound should change the caps so anyone can hear 90% of what the amp is capable of after 200 hours of so.

Anyway I have given up on the JC-1 and will listen to a Pass X350.5 next week.

Anyway, my rant is over.

Uh oh. Ah...I hate to tell you this, but the Pass needs 2,000 hours to sound good.

I agree with Audioengr's comments about global feedback vs no global feedback. That is, the amps with global feedback will typically produce more "slam" and tighter bass than the designs that lack global feedback. Part of this has to do with the amps having global feedback having a lower effective output impedance. The drawback to this is that most amps with global feedback will lose midrange liquidity and tend to sound "closed in", "less spacious" and lack separation of notes in terms of midrange and high frequency response. The more global feedback that is used, the more noticeable this becomes.

This is why i've said that Pass amps ( new and old ) sound very nice but lack bass definition and oomph. Even though the newer X series have massive power supplies and great current capacity in the output stage, their circuit design i.e. non-global feedback and slightly higher output impedance is what limits their bass performance.

Too bad we can't get someone like Curl and Pass to work together on designing an amp and then have someone build it with good quality parts. I think that both of these guys are capable of stunning work and the end result would be a pretty fabulous product.

Sim Audio? Never heard any of it. Read some very nice things about their products, but nothing earth-shattering.

MBL 101's??? Good luck. Finding amps that are both good enough sounding and powerful enough to really throttle them as needed may be a life-long task. I wish you all the best and hope you enjoy the journey : ) Sean
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Downunder,

What was the audition of Pass Labs X 350.5 like? Being underwhelmed of Halo JC1 performance after shorter break-in, you announced turning to Pass. I am deadly curious to know on first impressions!

Can anyone compare JC1 vs new Pass X 350.5?

Thanx.

Zoran, Macedonia

I am picking the Pass X350.5 up tommorrow and will have it over the weekend.
I will give an update after that