NTP 179-400 Limiter - 32 pin assignment ? (updated)

[ToniTonmann]

Hello,

can anyone help me out with a pin assignment for the NTP 179-400 card ?
I found schematics with pinouts here at the forum, but these are for 64 pin connectors, my cards only have 32 

Does anyone know more about these units ? I've read somewhere that there are different versions, with those pre 1990 had a different/more complex layout (and sound?). These here are from 1985.

Thanks,
TT

 

[jensenmann]

This is a schematic with 32 pin connector: https://www.gearslutz.com/board/attachments/geekslutz-forum/377736d1388330853-ntp-limiter-what-rectifier-ciruit-block-doing-schematic-ntp-179-400-schematic.jpg

 

[andow]

On some modules only the even or odd numbers are used. So maybe that's how the numbers translate: 1-1, 2-3, 3-5, ...

 

[ToniTonmann]

Thanks a lot jensenmann !! How could i've missed that post at gearslutz 
The resolution of the image is subterraneous unfortunately, but i've send it over to the technician in the hope than he can work with it.  I'll report later, should anyone come across that card as well.

 

[ToniTonmann]

Meanwhile i found a higher resolution version of the schematic, but i'm still lost with this.
It says input is 1+2, but which is hot/cold ? And i suppose 3-5 is input ground ? 24V is 31 (+) and 32 (-) ?
Also, the pins on the connector are not numbered...i assume that pin 1 is close to the "ZFT" module ?

I'd be very very happy about any help, my knowledge is limited (no pun intended) to soldering the cables

In case this is important, on the board it says NTP 179-4040-2, on the backside manufacturer label it says Type 179-400.

If anyone is interested in a detailed schematic for this limiter (with diagrams and parts list etc), let me know.


Thanks again,
TT

 

[musika]

I recently had the same question regarding power to the 179-400 in a previous post:

https://groupdiy.com/index.php?topic=62056.msg786356#msg786356

The module is not bipolar, it uses +24V and ground.

There is lots of good information on this NTP limiter in the forum,  Once you sign in to the forum, search on '179-400' and you will see all the past postings.

 

[PRR]

> The module is not bipolar, it uses +24V and ground.

This module uses a 24V UN-grounded power supply. NOT shared with any other circuit. Note that neither side of the 24V actually goes to shared ground!

Internally it really uses +/-9V. If you put it in a rack with shared +/-15V supplies, it can be modified, but not trivially if you are only a wire-man.

 

[ToniTonmann]

Thankls for the input, though i'm more confused actually...not bipolar..ungrounded....

Musika, following your link, you wrote :


"OK. Thanks.

+V at  pin 29

0V at pin 31

N/C at pin 32 then?"

So did this work ? Or leave 0V ?

I have a TAB N324 24V PSU spare that i could use solely for these modules. So i would only connect the  24V ? And what about the in/outs, how did you figure out the hot/cold pins ? How do you like these limiters, Musika - are they still in use ?

 

[musika]

ToniTonmann,

Connected 31 and 32.

Check out this old post:

https://groupdiy.com/index.php?topic=12092.msg154963#msg154963

That power supply you describe sounds like a good fit.  Yes, still in use.  I use them with a rather large 100uA meter pair, and mostly for the final analog to digital conversion, since my studio gear is almost all analog.  It depends upon the music content, but they are very transparent especially if used sparingly with a .5 to 1db on the meters  They tend to push down the frequency content as a whole instead of chopping or flattening the dynamic transients - somewhat more musical compared to other brick wall limiting.

 

[ToniTonmann]

ToniTonmann,

Connected 31 and 32.

Check out this old post:

https://groupdiy.com/index.php?topic=12092.msg154963#msg154963

That power supply you describe sounds like a good fit.  Yes, still in use.  I use them with a rather large 100uA meter pair, and mostly for the final analog to digital conversion, since my studio gear is almost all analog.  It depends upon the music content, but they are very transparent especially if used sparingly with a .5 to 1db on the meters  They tend to push down the frequency content as a whole instead of chopping or flattening the dynamic transients - somewhat more musical compared to other brick wall limiting.

Thanks Musika,

just to make sure (like PRR said, i'm only a wire-man): for the power supply i connect the +24 V from the PSU to pin 29, omit the negative wire and connect pin 31+32 on the module ?

Thanks for the link to the other thread, i've read through all of it and similar others..the problem i face is that there are many tips and hints, but none is ever confirmed to work. There's lots of talk about bringing out the controls, meters and changing resistors (which is way beyyond my understanding). I'm just looking for the info on how to connect the i/o's...so i hope to get some specific help from people like you who actually made these modules work.

Do you by any chance remember how you connected the audio I/O ? (e.g., in one of the threads some guys reported that when connecting the outputs as described in the schematics, there is a massive low end roll off ?)

 

[[silent:arts]]

Don't think too complicated, wiring is easy:

Input:
hot = 2
cold = 1
screen = to chassis, not to the card

Output:
hot = 20
cold = 19
screen = to chassis, not to the card

PSU +24V = 29
PSU GND (can be floating or connected to your chassis) = 31

Connect the cards Pin 32 to your chassis

Happy limiting.

 

[ToniTonmann]

A million thanks !

Grossartig, klarer gehts nicht. Tausend Dank und frohe Weihnachten

 

[Pan_work]

Hello Hello,
So nice to have all this informations... I have a NTP 179-400 "as is" so without chassis, and I want to connect it to try it. I have read all the post and im shure about what Im gonna to do, if I don't use a chassis to connect the ground ? Can I just try with only the Point 29 for +24 ? Another question trivial is... where is the 1 instead the 32 ? the one is near the ZFT Module or the opposite ? Thanks for helping

 

[Pan_work]

Finally, I use my DBX chassis 900 series. I jump a cable from the 24V entry and go to 29 pin , considering that 1 is on the side ZFT Mod. Then I put 31-32 on ground by connecting to chassis. Everything seems to be ok ! Just another question : on the card, there is two blue vario. Do someone know what these trims for ? thanks

 

[jensenmann]

IIRC it changes the release times. But check the manual, it´s described in there: NTP