Parasound JC1's vs. Sim Audio W10


I am looking for amps to drive some MBL 101d's and wonder which of these two monoblocks would work the best. Or any other suggestions that you might have.
husk01
I have no doubt these are fine amps when the breakin time is up, judging from the great endorsements I have read by so many folks. What bothers me is that should I buy a pair, and I am interested, I will have to play them on average 10 hours a day for 4-5 months before they deliver the performance I have paid for. That is a Hell of a long wait and if they sound lousy during that period, I don't think I would buy them, for that reason alone.

Can you please explain if there is a way to speed up the burn-in,and comment on the sound quality during this period. Will I enjoy my music during this time, or will I get discouraged?When I see these for sale on A-gon, I wonder if that is in fact the situation that has befallen the seller.
Thanks, Carl
Shane,

I know a number of people who have these amps (including myslef), and I am pretty sure all of them will tell you that prior to about 1200 hours, they relly do not shine. After that initial 1200 to 1500 hours they are a totally different amp. Feel free to e-mail me if you want to discuss them over the phone.
Break in time. Bob I am going to have listen one more time to a pair of JC-1's in the next couple of weeks.

What is the minimum play time until these amps will show most of what they are worth and sound pretty nice.

I had a listen to a pair 6 months ago and frankly was underwelmed - they had about 100-150 hours on them and I ran them in for another 50 of so. The dealer in total has probably only put about 300 hours max even now. He much prefers the sound of the moon W5 and has dismissed the JC-1's as he believes the long play time as garbage.

Bear in mind that the dealer is not going to let me play these amps for 1500 hours, and I am not going to buy anything on the promise of fundamental changes in sound at a later stage.

I would appreciate your honest oipen opinion as always.

cheers Shane
Bob,

Is it ok to turn the JC-1's on and off every day or does it take to much of a toll on them? I prefer to do this but certainly do not want to hurt the amps. Thanks for your responce
Hi Shane,

In low bias the unit will go into AB mode at about 10w which is audible with my Rockport speakers and isn't in high bias which allows about 30w of class A. I normally run the amps 24/7 in low bias and flip the switches to high bias when I want to listen to anything above tuner level......This saves a bit on heat and electricity and is a useful feature on this large amp........
Bob. What is the difference between high and low bias on a practical and sound quality level?.

thanks Shane
Cadougie - there are a couple of reliability things that could use improvement, mostly in older used JC-1's. Parasound is aware of these and some of these have been improved in the newer versions. I'm surprised that you had problems with a recent amp - perhaps it was from an older build lot.

I resolder all of the power transistor solder joints because some of these are not good in the older amps. The open-frame pots used for the bias adjustment seem to drift (or the other components drift), and finally, the inrush limiters do not have a lot of margin, so I use higher current versions. Once these things are changed, it is a very robust amp. I have had mine for several years and use it every day.
Gladstone, I run my JC-1s in high bias 24/7 and have for a couple years for both my Rockports (an easy load) and my Sound Lab M-1s (tough load) and curious what speakers are a tougher load than the Sound Labs? I chose the parts in the units and will say that those cheap Superior Electric posts cost five times as much as what is normally used by Parasound, are the originals that everyone copied and eat things like the WBT, Edison Price and Cardas binding posts. They were chosen for their performance, not their pricing. The JC-1 is what it is, a very powerful amplifier that can be machine built in Taiwan using specified parts that also sounds very good.........Sure we could do better if the retail pricing was 25K/pr........

Bob Crump
CTC Builders
Nothing wrong with the build quality of the JC-1! It is nothing short of amazing to get the parts quality inside that those bad boys (for the money or any other way you want to express that)exibit. I have seen a lot worse out of some much more expensive products.
I didn't warm up to the amps (but it could have been an issue with breakin, want deny that) but they were a couple of the best built amps I have seen.
Mahandave
As an owner of a pair of JC1's which I run through a Moon P-5 pre, I would have to say that you have no idea about the JC1. Please open the top of one of these and see for yourself whats inside before rushing in to comment about them!

Since I already had the Moon P-5 pre before I bought the JC1, I naturally looked at Moon Power Amps. Having chosen the JC1 over the W6 should indicate the quality of the JC1's. In fact most magazines, including Stereophile who gave JC1's a fab review don't even have any ads endorsed by Parasound in their magazines. This should also be indicative to the build quality of these amps & their sound. Go ahead hear them have a look and then you are more than welcome to comment!!
My apologies Krevzeik. Daltonlanny, you are correct. I meant to direct my comments to MahanDave.
The JC-1s are good. On a demanding speaker, however, they must be run in low bias mode, which does sacrifice some sound quality.
i had recently bought a pair of jc-1s and also had a negative experience. after hooking them up, noticed a low level buzz coming from one mono block when you were close to it. called parasound and was told this was "normal". when i told rep. the other was dead quiet, his response was,"well, that one is beyond spec." a second problem was one of the standby lights on the front panel did not function properly, and this prompted the dealer to take them back and get me a new pair. i hooked up the new pair, and played them for about 20mins, and heard a loud pop. one of the monoblocks had "blown" (not a fuse), and quit working. at this point, i had had enough. they went back to the dealer and i am currently waiting on a new amp from a different manufacturer. the parasounds may be great sounding amps, but my experience speaks to the overall build quality and quality assurance.
Timo,
In all due respect, I think you meant Mahandave instead of Krevzeik as the one criticizing the JC-1's.
Krevzeik defended the JC-1's.
Thanks Timo.
I will also give the JC-1s my highest recommendation based on extensive listening to my best buddy's system which includes a pair of these amps. I certainly won't say they are the best amps available, but they certainly ARE among the very best available at ANY price, IMO. They are well built, with very high parts quality (just pop the lid on one of these puppies to see what I'm talking about).

Krevzeik: I think you should refrain from making such bold statements like you did in this thread without first, knowing all the facts and second, you better be able to back up what you say or you should specify that your statements are based on your opinion and not fact. You shouldn't trash a product without first knowing the facts. Please do your homework before typing.
As a very satisfied owner of the exceptional JC-1 monoblock amps, I must defend them from the undeserving attack about the build quality, and parts quality by the first responder to this thread!
The JC-1's have no "junk" parts on the inside or outside!
They are built like a tank, and use some of the highest quality and best sounding parts currently available!
I have no problem at all with the Superior Electric binding posts. The JC-1's have received rave reviews from the audio press as well as audiophiles for their excellent sound, PARTS QUALITY, and build quality! As Brian Walsh said, they are factory hot rods!
And you MUST give them their required LONG break-in period, or you will never know just how exceptional they can sound!
Mahandave, those binding posts on the Parasounds were chosen for a reason, that overall they sound better than anything else... Superior Electric binding posts are the original, much imitated with a lot of cheap lookalikes that don't sound anywhere close to the same... If you still can't get over the appearance then I suggest you take a look inside and you will be surprised... More importantly, find a dealer who has fully broken-in JC-1s that are available for home trial and listen for yourself... One of the nice things about the JC-1s is that they don't need to be hotrodded, as they come that way from the factory...

Brian Walsh
Before you start trashing a product, get your facts straight. The "cheap plastic" binding posts on the JC-1's are Superior Electric binding posts, and they are not cheap junk, and were chosen by co-designer Bob Crump as sounding superior over numerous other choices. I hardly think that the numerous massive Nichicon Gold Tune caps or the Vishay resistors inside qualify as anything other than parts among the highest quality and cost available today.
I look at the back of the Parasounds and see the cheapest plastic 5way binding posts and wonder what else is junk inside if thats the quality on the outside? the Sims are pure quality but you can do better musiclly. A McCormack DNA 500, Belles Ref.150 in mono,Ayre(the big one),BEL-Brown Electronics Labs mk5 in mono,Clayton mono's all will beat the Mark Levensons, Krells, Pass,Jeff Rowland Plinius,Classe etc,etc. I don't believe stereo or mono amps will effect the soundstaging nearly as much as the speakers output being exactly the same. And though I am fully ballanced with my system, I don't put any advantage or dissadvantage in going ballanced or single ended.