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Anyone have/ordered the Job 225?

There's almost no consumer impressions of this amp on the internet... but the 6moons review is intriguing.
girlsgeneration
srosenberg's avatar
srosenberg
209 posts
 
@grannyring...
what is the sensitivity of your speakers and the gain of the preamp you are using?  this matters much with the job's 35db of gain and 0.75V sensitivity.  i found that i also had a hiss with my 94db speakers and modwright preamp until i bled off quite a bit of gain at the inputs to the job.  after doing so, the noise floor was back to where i expected - ie, no noise whatsoever.

that said, my amp gets warm, but never too hot to rest my hand upon, even after several hours of use, so it's possible there may be more going on with your amp.
grannyring's avatar
grannyring
6,479 posts
 
How did you bleed off gain at the inputs? Speakers are 84db effecient and my tube preamp I am not sure about. It is not high gain however. 

The top cover is warm, however I am talking about the heat sinks on the back of the amp only. These sinks get very, very hot. 
georgehifi's avatar
georgehifi
10,312 posts
 

0.75V sensitivity for full output! With all this gain and 94dB speaker why use a active preamp with gain?? Most sources give out more than 2v these days, even phono stages, and the Job I believe is 100kohm input impedance, all this is a perfect match for a passive pre such as the $49 Schitt Sys

http://schiit.com/products/sys

Then you will not have any hum or noise problems and as a bonus zero colourations that all actives have.

Cheers George

  

devilboy
1,176 posts
 
Granny, I agree with George in that the 225 is very "passive friendly" as long as output impedance of source isn't too high. However, its input impedance is 51K.....not 100K.  Also, most every source has at least 2V output.
What concerns me is the tube preamp. I'm pretty sure Srajean at 6moons said to be very cautious pairing the 225 with a tube preamp. The 225 has no DC protection so any DC leakage goes straight to the speakers!  Not good.
IMO, the 225's specs SCREAM passive. I'm not going to get into the passive vs active debate hear. That's another topic for another thread. 
What puzzles me is at 84db, your speakers are not efficient. I would think you would hear LESS hiss and hum beacause of that. 
That said, I think your active preamp is putting out too much gain for your extremely sensitive, 35db job.
Like I said, im FAR from an expert with this here.  Just my 2 cents.
devilboy
1,176 posts
 
I read one if your other posts again. In it, you say the heatsinks get much hotter the louder you go. I'm wondering if the Job might not like seeing an 84db speaker. I find this hard to believe, though.  I've read that the 225 puts out more power than its 125 w/ch spec says.
Again, I doubt it. I'm just trying to think of any possible scenario here.

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