Ntp 179-120

[pucho812]

Does anyone have photos of this unit outside of a chassis.
I know we have schematics in the tech doc section
But I was given a pair to look at in a desktop box. One works, one doesn’t. Aparently they both worked when the owner first received them from eBay. Not long ago, like a couple of months.
I haven’t made any test measurements yet. But hoping to see one as this desktop case looks nearly impossible to take apart.

 

[Youngwhisk]

Are you able to post a couple of pictures of the case?

 

[pucho812]

Here is a front shot. I pulled this off reverb as I am away from the unit. But it is this case

 

[pucho812]

Here is a back shot with rear panel removed

 

[Youngwhisk]

It would have been nice if they had left enough slack to pull out the unit with the back still in place. It wouldn't have taken much more wire.

 

[Viitalahde]

There seems to be a Youtube video:



I absolutely *love* my pair. I don't service them myself. My NTP guru is Elberg-ELT in Denmark. The pair I have was very problematic with all of the op-amps acting up, and what not. Elberg has swapped all of the op-amps to his M100 variation, calibrated them, and they've been running smoothly ever since.

As far as I know the FET's are a problem. No replacement. I do have 3x cannibalized NTP limiter modules around that should have the same FET. Someone told me the FET's used in the limiters are the ones who fell off the spec, but who knows. I hope I don't ever need to start looking at alternatives.

 

[pucho812]

There seems to be a Youtube video:



I absolutely *love* my pair. I don't service them myself. My NTP guru is Elberg-ELT in Denmark. The pair I have was very problematic with all of the op-amps acting up, and what not. Elberg has swapped all of the op-amps to his M100 variation, calibrated them, and they've been running smoothly ever since.

As far as I know the FET's are a problem. No replacement. I do have 3x cannibalized NTP limiter modules around that should have the same FET. Someone told me the FET's used in the limiters are the ones who fell off the spec, but who knows. I hope I don't ever need to start looking at alternatives.

Thanks for that information

 

[pucho812]

Finally get to this. Dude dropped it off early in case I had time.
Both units power but it does some strange behavior on the right side unit.
Cuts in and out.
Hard to tell if it’s dirty switch contacts or if it’s capacitors or bad solder joints. maybe bad opamps?

 

[gyraf]

I'd check 1)switch contacts 2)the tantalums (if broken, replace with tants also) and only 3) the opamps

 

[pucho812]

Reseating the module seems to temp fix the unit.

 

[pucho812]

i have both units now running but there is still an issue. Feed the units a 1k sine wave. One unit outputs the nice wave the other unit outputs a more squared off wave. Sadly I currently do not have a test jig to run modules away the unit.