Neumann High End Limiter.

[concretecowboy71]

Since we were all talking about groove geometry the other day, another topic I think would be interesting to discuss would be how everyone uses (or not) the high-frequency limiter in the cutting rack.

I try to be as conservative as possible with it, but rarely bypass it. Is it necessary on all cuts, or is it a "problem solver" to use only when needed.

Does anybody have info such as the frequency range, attack, release and ratio?

I have seen some masters drive it into fits at conservative levels and then other barely even make it tick. I know all masters are different but would love to give my clients more guidance regarding this piece of gear and how it might "change" their master.

[opcode66]

Sustained highs will drive it nuts. I just cut some reggae and the needles didn't even move.... But, cut some girl singing and they are bouncing up a storm.

I set my switch to "On". I don't use the Program Control setting. I never set mine higher than 3 for left and right. Anything more than 3 will make the music sound really dull and lifeless.

That in combination with the correct low pass filtering in my audio chain is all that is needed to get good cuts and maintain cutterhead protection.

[Nickou]

the best thing to do with the acceleration limiter is to do not use it !

in my rack , it is not connected to the audio path , and since , I am very happy with it ...

[montalbano]

The acceleration limiter is a great protection for the cutterhead but it can be a real track killer as well.
We never turn it off; we usually monitor the cutterhead to check its behavior and if necessary, we set the correct eq settings in the transfer console in order to reduce its action.
This 9 times out of 10 preserves the "fresh" sound and at the same time strongly reduces the action acceleration limiter - in my view it is the smartest way to go because it keeps the customers happy and your cutterhead safe at the same time.
And - most important - you get a crispy clean cut.

[jjgolden]

To my knowledge it acts as a high shelf with the knee starting at around
5-6k. When it has to dig in hard your hearing gain reduction in frequencies even lower than 5-6k which really dull things down. Kind of like riding a treble knob on a hi-fi stereo I guess.

Anybody have accurate numbers for the AL frequency curve?

JJG

[JayDC]

To my knowledge it acts as a high shelf with the knee starting at around
5-6k. When it has to dig in hard your hearing gain reduction in frequencies even lower than 5-6k which really dull things down. Kind of like riding a treble knob on a hi-fi stereo I guess.

Anybody have accurate numbers for the AL frequency curve?

JJG

sounds like it works like a desser, just effects a little more then just the sssssssss...

I always hit my dessers hard, i hate sizzle.. I hate pre-mastering things that have so much sizzle that it hurts your ears.. sizzle to me is like low frequency mud, funny though most people think the sizzle adds clarity, and I believe it clutters up the high end.

[Nickou]

yes it is a deesser
it means than you can use any multiband compressor to do that

[gengy]

I don't never use the acceleration limiter in the neumann rack!

[concretecowboy71]

Thanks. I have been leaning towards using plug-ins for de-essing also. I have done a few jobs where I use a de-esser coming out of the computer and then a lower setting on the AL in the rack.

I was taught a long time ago by mix engineers that two compressors working in smaller increments is more transparent than one slamming away.

[JayDC]

yes it is a deesser
it means than you can use any multiband compressor to do that

A Desser reduces the effect of sibilance, and you probably could use a multiband compressor, they usually add to the sound as oppose to subtract from the sound. I wouldn't..

I would more then likely use both, desser then a multiband compressor or EQ. This way you remove the sibilance, and raise the volume of the highs to compensate. You loose the sizzle, but the highs will come through nice, sharp and clear.

I would be interested in trying this neumann limiter, but I would change it's position in the signal chain. I'd put it before the riaa encoder..

neumann limiter -> multiband compressor or EQ -> limiter -> RIAA -> limiter -> amps -> head

You guys can't afford my method of calibrating the last limiter though. I set the last limiter in the chain to the highest peak -0.5db's from the point that my fuse blows. I would be afraid to do this on such expensive equipment.

Everything in my chain stays below -1.0db, and I have the gain on my amps high. I find that running the computers audio card into the yellow or red may add to the THD..

[jjgolden]

Hi Clint,

Yes, turning back to your original question.
Using an outboard de-esser or de-esser pluggin gives you more precise/musical control over sibilance.
The Acceleration limiter on the SAL/VG rack is mainly (now days) to protect the cutterhead, especially the SX68's and older.
Knowing the tolerance and limits of your system, it is possibly to turn it off for certain cuts, but when in doubt at all, leave it in just as a precaution.
Also, Keep that helium going especially if you've got sustained high frequency stuff like speed metal high hats, etc...


JJG

[dietrich10]

Nothing more to add but anyone selling their Acceleration Limiters please drop me a line. Friend has rack missing them and looking.

sorry to spam your post Clint!

[markrob]

To my knowledge it acts as a high shelf with the knee starting at around
5-6k. When it has to dig in hard your hearing gain reduction in frequencies even lower than 5-6k which really dull things down. Kind of like riding a treble knob on a hi-fi stereo I guess.

Anybody have accurate numbers for the AL frequency curve?

JJG

Hi,

I think you are correct about the operation of the limiter.

The entire protection scheme, including a graphic showing limiting action vs. frequency and level for the Neumann system is very nicely described in the JAES paper found on page 277 of the Disc anthology Vol 1. It is titled:

Essential Equipment for the Transmission of High Peak Levels in the Disk-Cutting System SAL 74/SX 74.

I would not, as JayDC states move this in the signal path as they have taken into account the presence of the RIAA and the current response of the cutterhead in the design of the limiter.

As a hobbist, I'll never get to use an Neumann system, but its very interesting to see how well designed these machines were given the state of the art at the time. I suspect, if used lightly, the limiter would not be noticable. If you are really pounding the thing, it probably means you need to back off or use some other method to control the source material.

Mark

[Bonati]

I don't use them, but I also...don't have them. I own a pair but they are uncalibrated at the moment and out of the chain. I use a Maselec MPL-2 here for the high-frequency limiting work. This unit or the MDS-2 (no peak limiter in this version) are the best "third-party" hardware solutions I know of. I've never been able to make plugins work as well.

[JayDC]

I use the Waves Desser included in the diamond bundle.

The only advantage you have using hardware over software is the ability to overdrive your equipment, which if you do in the digital environment, will create all kinds of horrible distortion (not the good kind, like if you overdrive a tube amp).

For the price of that one unit, you can get a whole suite of professional tools.

The disadvantage I see in hardware is wire noise, ground loops, and expensive costs.

I really like this Maselec unit, if I found hardware to replace all the plug-ins in my chain I would consider converting. At this time however, I cannot see spending 3K to have audio come out of my audio card, though this unit, then back the computer, through more plug-ins, then back out of my computer to the amps. That would surely raise my noise floor...


Hmmm... Looks like I found the hardware I want, all by this company..

A Maselec MLA-3, MDS-2 or MPL-2... Just need to find a good limiter

[opcode66]

Most plugins are way too agressive in my opinion.

As Mark correctly stated, if used lightly they are hardly noticeable. But, still provide the protection you absolutely want in order to keep your cutterhead safe.

Knob set to "on" and the left and right set anywhere between 1 and 3 seems to work well for me. I've been cutting loud dance tracks with loads of highs with no problems.

The only issue I've had was with respect to overexcited highs. I fixed that in my mastering chain. Now, everything is butter.

[dietrich10]

My AL is always 'IN' but unless needed knob not turned at all. Sometimes it does add the 'sound of vinyl' in my opinion which can be needed on metal/punk with pushing 3k-12k.

At some point it will get 'Muthed'

[montalbano]

Opcode and Dietrich I definitely agree-
Keep in mind that the AL reads the CURRENT coming from the feedback circuit and operates consequentially. A deesser (physical or plugin) will read the content of the signal accordingly with the set parameters and will dynamically reduce the output level on that frequency range.
Of course it will be better - acoustically speaking - because you will have more control, and it will even have a positive effect in terms of less stress for the cutterhead, but you will not have the same direct control on the feedback current which effectively you have with the AL.
This is why I think that the best is to combine both things (eqs and desser and THEN the AL) in order to keep the AL working a very little or not at all but without bypassing or removing it.

[Nickou]

Opcode and Dietrich I definitely agree-
Keep in mind that the AL reads the CURRENT coming from the feedback circuit and operates consequentially. A deesser (physical or plugin) will read the content of the signal accordingly with the set parameters and will dynamically reduce the output level on that frequency range.
Of course it will be better - acoustically speaking - because you will have more control, and it will even have a positive effect in terms of less stress for the cutterhead, but you will not have the same direct control on the feedback current which effectively you have with the AL.
This is why I think that the best is to combine both things (eqs and desser and THEN the AL) in order to keep the AL working a very little or not at all but without bypassing or removing it.

the acceleration limiter is plug after the input stage ( transformer for the sal or opamp for the sal 74B) and before the input of the RIAA encoder



so I don t know how the acceleration limiter can read the current comming fron the feddback coil or feedback preamplifier ... in fact , it does not have any information coming from any thing else than the input transformer of your rack ( exactly after the transformer there is a adaptation of impedance and the signal is going to th AL and to the monitoring)

if you use vst plugs to do that , of course you can think than the sound is not so good ... but probably the best is not using vst plug to make mastering , but you don t need to buy a weiss DS1 mk3 or thing like that ( even if this one is the best tool to this task ) , there is some plug for DSP system wich are working perfect
I still have the acceleration limiter inside the rack , but it is not plug in the signal path , and I won t replug it
Actually I use the AL for production : I instaled on it balanced input and output and it is nice for voices ... but for mastering no , except if you love the GZ sound ...

As Flozky said , the best for it is bypass , and I dont think " the vinyl sound " comes from the AL , for any style of music
to be more precise , a lot of bad sounding records has been done using this rack

[mossboss]

Great thread This is the way to go guys plenty of input as well as points of view
AL is always on iin all our cutting rooms
It has done a great job protecting the head over many years
We have never cooked one as yet even though we blew about 20 odd output trannies on the main amp in Aus
3 or 4 of the output cards went down due to deliberate static on a doom metal track, only once and all at the same time
Scary stuff
So unless you have plenty of spare cash for another head or an expensive rewind do take it off
Else leave it there
It was put there for that reason alone
Well, any doubters can ask around, there plenty of horror stories about cooked heads out there thats for sure
You need to do a lot of cuts to cover that kind of cost, despite all the reasons given here you got to be a brave as well as a rich man to take it off line
Cheers