How bad can opto compressor be?

[JoaT]

I'm considering buying SM Pro Audio's 8 channel compressor thingy, OC8E. It's reasonably priced and would act as channel insert dynamics for my console.

Now the question is, where's the catch? These are not mentioned much anywhere, and yet they are cheap and reasonably versatile (Attack, release, treshold and ratio for each comp) optical compressors.

The obvious lacking thing here could be the sound. But how crappy can an optical compressor be? And is there any reason why they should not work on my intended application?

[Strut78]

Originally Posted by JoaT

I'm considering buying SM Pro Audio's 8 channel compressor thingy, OC8E. It's reasonably priced and would act as channel insert dynamics for my console.

Now the question is, where's the catch? These are not mentioned much anywhere, and yet they are cheap and reasonably versatile (Attack, release, treshold and ratio for each comp) optical compressors.

The obvious lacking thing here could be the sound. But how crappy can an optical compressor be? And is there any reason why they should not work on my intended application?

Hi, Not too sure about the model in question but there are some excellent optical compressors out there, I use the Pendulum OCL-2 in my mastering room often, great comp but it has a custom optical cell that responds much faster than most.

If you are doing gentle levelling (vocals etc) then optical comps can be great, but If you are trying to shape Percussive tracks like drums you might be better sticking with a VCA or FET based comp.

[JoaT]

Thanks for the reply! As I intend to use them as channel compressors, the gentle levelling is probably the most common task. I intend to buy a few other, more versatile compressors to use as bus compressors and other applications where more drastic squashing is required. These are merely for getting the dynamic range tamed a bit when needed so the material is easier to mix.
I think I will bite and get myself one and test it myself for the application...

[RiF]

Wow! That thing costs just EUR 299!! That's EUR 37,5 per compressor.
But... It doesn't have balanced connections and the gain reduction meter is just a single LED that goes from yellow to orange to red.
Adding to what Strut78 said, I don't really don't know how to use 8 opto compressors like this in a mix, though...

[JoaT]

As channel inserts it would compress the individual channels chosen.

Can be applied to 8 channels of your choice simultaneously.

I think the primary use for something like this nowadays would be live processing. Not much feasible use for this if you don't have a proper mixer.

But yeah, cheap as heck and the lack of balanced inputs is something I can well live without. Not running a high end facility here anyway (though I am heading to that direction. But that's distant future).

As other compressor choices I am going DIY with Hairball audio's 1176 (stereo pair), la2a and GSSL master bus comp. I think I'll get me an Art Pro VLA II too at some point.

[AaardVaaark]

RIF:

I don't really don't know how to use 8 opto compressors like this in a mix, though...

JoaT:

As channel inserts it would compress the individual channels chosen.

Scuse if I'm wrong, but I think what RIF was getting at was, "Why would you want to do this?"
The likelyhood of you needing 8 channels of the same cheap compression is pretty low IMHO, and you'd be much better off getting 2-channels of something nicer!

If you just need to level on mixdown it strikes me you could have compressed more on tracking, or, assuming you want the dynamics, you could use automation to even things up on mix .

If it's the sound you're after, you might as well get a good one, since you have the FET side covered with the Hairballs.

My 2c? You'll probably be better off going for the ART or saving for the LA2A.

HTH
AV

[JoaT]

AaardVaaark: Ok, this is a point of view I suppose...

Having the ability to tame the dynamics down on individual tracks is something I like as an idea. In fact, when working ITB I have accustomed to just slap a compressor in any track when I feel the need. The luxury of plugins, I suppose.

But with the HW environment every instance costs actual money. Therefore I can't afford 1176 on every channel and then some. I can mix without boatloads of compression too, and using buss compression is also a viable option. But for the price the 8 channel unit is surely tempting.

Because I don't know how good it is (never heard one myself) I named the thread as I did.

[nosebleedaudio]

Just to add what has been mentioned; an Opto based compressor can be very good or Not very good..All depends on HOW it is used..
Tube Tech CL1b uses an Opto in the circuit..
Some of the cheapest gtr pedals use Opto's in the circuit...

Same goes for VCA based compressors..

Like any gear..check it out..Listen..

[Sigma]

la 2 , 3 and 4's used optos ..the cool thing about them is they have a very fast attack time and a variable "return to 0"

you hit it past 3 ds of compression and it "slows on the return at -3 to 0 dB of compression

example i hit it with 7 dB of compression..it comes back rather quickly then slows down on the last 3 dB before 0 amount of compression

great on vocals and bass etc

some people don't like la 4's because of the cheesey op amp in them..but they and the allison gain brains were the only compressor/limiters we had at our studios for their first 15 years

12:1 and chopping off 3-5 dB of vocal peaks to tape they were sweet

[nosebleedaudio]

Originally Posted by Sigma

la 2 , 3 and 4's used optos ..the cool thing about them is they have a very fast attack time and a variable "return to 0"

you hit it past 3 ds of compression and it "slows on the return at -3 to 0 dB of compression

example i hit it with 7 dB of compression..it comes back rather quickly then slows down on the last 3 dB before 0 amount of compression

great on vocals and bass etc

some people don't like la 4's because of the cheesey op amp in them..but they and the allison gain brains were the only compressor/limiters we had at our studios for their first 15 years

12:1 and chopping off 3-5 dB of vocal peaks to tape they were sweet

The LA2 and LA3 use a VERY different type of Opto compared to the LA4..
LA4 use's an Opto with a LED..VERY fast compared to the very special lamp in the TB4...
Also where and how they are used in the circuit is also VERY different..
My point is saying the LA3 and LA4 are both Opto compressors is not the whole story..

[mexicola]

Originally Posted by nosebleedaudio

VERY fast compared to the very special lamp in the TB4...

It's an electroluminescent panel like that used in an alarm clock, not a lamp...and it's a T4B

[Sigma]

Originally Posted by nosebleedaudio

The LA2 and LA3 use a VERY different type of Opto compared to the LA4..
LA4 use's an Opto with a LED..VERY fast compared to the very special lamp in the TB4...
Also where and how they are used in the circuit is also VERY different..
My point is saying the LA3 and LA4 are both Opto compressors is not the whole story..

that's a giventhumbsup

the attack and decay of light source gives the attack and release characteristic of the opto as compared to other type compressor/limiters..i was commenting on the general characteristics of the opto and the non linear release characteristic of it when pushed

compressor designs are so differnent you head will spin...feed back ..feed forward ..opto... true tube etc etc etc

[nosebleedaudio]

Originally Posted by mexicola

It's an electroluminescent panel like that used in an alarm clock, not a lamp...and it's a T4B

Wow..you need to look up the word LAMP...
100% aware whats inside a T4B, repaired a few over the last 35 years...
A couple of LAMP's and a couple of photo cells...

[Eganmedia]

Originally Posted by JoaT

But how crappy can an optical compressor be?

I remember a model from Rolls/ Belari that sounded completely broken. Every one I've ever heard sounds like that.