ntp limiters

Hi there,

Do you have the schemo? I have it somewhere if you need it, but I am not sure where . . . I am not sure what you mean by "Logic Selection". - there are some switch selections for release times - single release time and dual release times. Also, channels can be linked for stereo, and a 1ma meter can be attached to show gain reduction. I shall look for the schemo if you like.

Good Luck!


ANdyP

ps. - don't tell too many people how utterly outstanding these are. Mine sit permanently at the end of my mixing/mastering chain. I consider them to something of a secret weapon. I like to j-u-s-t see the meter moving. If I bypass the NTP's I have to reduce the output of the SSL by up to 6dB, Yup, that's 6dB folks . . . Almost entirely inaudible over this range, any discernable effects are merely that of a tightening of the bottom end/Kick. these puppies are no panacea, though, - your mix has to be pretty much outstanding BEFORE it hits the NTP's, or everything will go well out of shape. Keep shtum, and perhaps they can still be picked up for a song! These puppies were thousands of pounds when new . . . . . :green: [/i]

:green: :green: :green:

just hope I can find that schemo!


:thumb: AndyP

dimebag,

I found 'em! Please be patient, I don't have a scanner. I'll have to think who to go to.


PAtience, my freind!


AndyP

Dimebag,

I have not forgotten you. Today I went to scan all the paperwork I have on 179-400 Limiter(16 pages or so!). - F@@king PC's, i just couldn't get it to work. Please be patient, I'll get my wife to scan it on monday/tuesday when she is back at work.

Keep the faith!


ANdyP

> the selection of the recovery times. i'm a bit stumped

According to the data: you need three SPST switches for Attack, three more for Recovery. The switches short pins A, B, C to ground, or go open. Ground is "0" and open is "1". The table in Note 2 tells what you get for each of the 8 possible combinations of 3 switches. All 3 shorted is 4S recovery, C shorted and A, B open is 400mS.

Instead of 3 switches, you get a "hexadecimal switch" or "BCD decimal switch" such as DigiKey 401-1037-5-ND. (Do NOT get "complement".) Connect switch pin "C" to ground, switch pin "1" to limiter "A", switch pin "2" to limiter "B", switch pin "4" to limiter "C". Ignore switch pin "8": what you really want is an Octal switch, but they don't make them any more, you buy a 10 or 16 way switch and ignore the excess.

It would also be possible to do this with a simple 1-pole 8-throw switch. Ground the wiper. Start connecting diodes, band-end to the switch, to the ABC terminals marked "0" in Note 2. Position 0 has no diodes. Pos 1 has one diode to pin A. Position 7 has three diodes, to A B and C.

You could also use open-collector TTL chips to interface to a PC printer port... total overkill for one or two such boxes.

@strangeandbouncy: Do you change your recovery time settings often? Or do you leave them on one setting?

If you don't change them a lot a dip switch on the back will do the trick as well I guess, although I really like PRR's solution with the rotary switch.

I can´t open that .doc... Do you have the schemaic already? I have a not so readable one.

Radience,

I pretty much only use mine at 0.1s release, with no second time constant set(ie, no Auto function). Sometimes I even go for 0.3 secs, but not very often. The beauty of these puppies is you can push the output from your analogue gear into your digital domain, with very few artifacts at all! I have to lower the output by @6dB to avoid clipping, if I remove my NTP's. Over this range(about 2dB or so visible on my GR meter(Do use one of these btw - very useful!)) the limiter is virtually transparent, with just a hint of tightening of the bottom end, as you would expect. I have got a 100uA meter instead of a 1mA one, so that the needle actually registers the kind of GR I want to see, ie 1/2 ofa dB/1dB/ 2dB up to 8dB or so. Stock 1mA is not sensitive enough for me. I consider these to be one of my secret weapons, and hate mixing without them! They definately need a very good balance going in to them, unlike say an SSL mixbuss compressor, which kind of sorts the balance for you. I mix without, and add them when I am ready to bounce my final mix.

Guess It depends on what you want them for. I did have them strapped over a pa for a club for a while, where setting a very very long recovery on T2 (ie 10 secs) stopped the dj's from pushing it too far, since it took a while to get up to level again. Mean I know, but very effective!

Enjoy!(eventually!)


ANdyP

Rafa,

i have all the documentation for this, incl schemo, but have been unsuccessful at scanning so far! Keep your eyes peeled for them this week(I Hope!)


ANdyP

> I can´t open that .doc

You have to hit "Cancel" at the password prompt.

Here is a PDF version: NTP Photos PDF, 1.3 Megs

On both recovery time 1 and 2, position 0 and 1 are fixed. What does that mean? fixed?

Here it is, Folks,

download it from my .mac account. It is as a pdf.


http://homepage.mac.com/strangeandbouncy


Enjoy!


ANdyP

strangeandbouncy

Hi!

You say you've got a meter on your 179-400 NTP. Can you tell me how it works? Does it indicates "0dB" when no limit occurs and then goes down when the NTP limits the signal (like a "normal" GR Vu-meter), or does it works another way?
I've to set a Vu on mine and it makes me problems I still haven't solved...

Thanks

Hey!

It should be 1ma GR meter, and it works "the wrong way round" to, say, an 1176 meter - just like a G-SSL, or Pye or A+D . . . . I actually have a more sensitive meter, giving double the sensitivity of the corrrect meter. This is because over the range of gain reduction I like to work with it, There is very little movement with stock part!

vu meter won't work(immsm)

All da bestest!


ANdyP

Thanks for your answer, but my poor English don't understand what
" (immsm)" means !!?

manarm,

Simply use a 1mA DC meter.

Jakob E.

immsm . . .

if my memory serves me

OK Thanks

Just have to make it admit to my customer !!
Another side of the job ... :thumb:

Hi folks,
I´m in the middle of racking some NTP 179-400 limiters.
Everything is working fine so far besides the Bypass and Stereo Link - Switches.
If I get it right Bypass is engaged when pin 16 ist connected to pin 31 (or ground in my case) and Stereo Link is achieved by linking pin 28 of two units. What could I have done wrong?
Thanks in advance, Emre

PRR said:

> the selection of the recovery times. i'm a bit stumped


It would also be possible to do this with a simple 1-pole 8-throw switch. Ground the wiper. Start connecting diodes, band-end to the switch, to the ABC terminals marked "0" in Note 2. Position 0 has no diodes. Pos 1 has one diode to pin A. Position 7 has three diodes, to A B and C.

Click to expand...

Hi PRR !

Do you have a shemo or something to do that ? I must confess that I don't see the picture to realise this excellent trick !

Cheers !
Bruno.