1176 or LA-2A !!! :lol:

I always use a comp while tracking
Seb's choices are very good and very typical of the music biz

Urei 1176 - FET and discrete with some models being all transistors and transformers throught to some models being transforerless and contain opamps.

Teletronix LA2a - Tubes and opto based and use a T4B which contains the translucent element.

both units have copies and clones ... some are even very good.

Some people swear by DBX (VCA-based) and Aphex units for specific types of vocals and styles.

I think Kev summed it up (no pun intended). The only inaccuracy in his comments were regarding the UREI/Universal Audio LA 2 and LA 3 which use an electroluminescent panel with light-sensitive resistors in an enclosed module. The other optical limiters out there frequently use LEDs with light-sensitive resistors, or VACTECs, which have totally different ballistics to the electroluminescent panels and thus has a completely different compression characteristic. You can't beat an 1176. Now that utilizes an FET as a variable resistor along with a peak detector circuit. The LA 2, LA 3, et al. are not as well suited for limiting as they are more similar to the DBX, RMS detectors. The latter compressor limiters have more of a " soft knee" whereas the 1176 has a hard knee. The soft and hard knee indicate how smoothly the limiting/compression starts. Each one has its own character and you can only tell what you want through experimentation and experience.

I hope I have confused you enough here or is that hear???

Ms. Remy Ann David

I'm a compressor jukie so I don't thnk I could suggest ony one compressor, way to hard. The ones I use most often for vocals (tracking and/or mixing) is usually a 1176, LA2A, 160SL, Red-7, Elop & Var-iMu, Groove Tubes CL1s, Tube-Tech CL2A, API 525, Meek VC1Qcs. Many times it takes some combo of them to get what I am after.

As many as I have, I still find that I wish I had more such as either offering from Chandler. the new Fearn compressor, Atomic Squeeze Box, GT Glory, Daking, Avalon, Neve or clone of a 2254 and/or 33609, the all mighty Fairchild or anyting close to it, La-La or EAR units. One of them is gonna be mine this year.

Kev,

What do you think of Gyraf's 1176? I built the SSL, and I'm thoroughly pleased with it....a night and day difference from plugin comps.

What about the Bloo LA2A? Is that one good?

That dude on that board came up with a PCB version of the LA2A, which is what I am currently working on. I think it will work out cheaper (total approx $600) than the Bloo, but require more work. Might look into it. I haven't heard anyone complain about the Bloo though. G1176 is on my list of things to kill as well. 8-)

If you're going to do an optical, don't use LEDs. Go with the original electroluminescent panel's. You've seen those nightlights for your children that are completely flat and look like little TV screens. That's an electroluminescent panel and what is inside the L. A. 2 and L. A. 3. Now the nightlights are larger than they need to be but you can just cut them down with a scissors. Then you'll probably want to order some of the light sensitive resistors that Universal Audio is currently using. They are different than your run-of-the-mill types. I have rebuilt a number of LA 3s that way. I wasn't sure if the electroluminescent panel would work once I cut it? I put a little clear cellophane tape around the edges where I cut it. It's been working great for years. Now of course you will need to mount that inside a light proof can. You may need to also put a piece of paper with an iris like hole, to bury the amount of light striking the light-sensitive resistor for proper operation. You must do this all in very low subdued lighting. Once you believe you're finished, you should wait about 24 hours while this thing is in the dark before firing it up and seeing how it does.

Remy Ann David

...or just buy a T4B from here:
[[url=http://[/URL]="http://www.jblpro.c…"] Attenuator, Electro-Optical for the LA-2A [/]="http://www.jblpro.c…"] Attenuator, Electro-Optical for the LA-2A [/]

I use these primarily

Purple MC77
Crane Song Trakker
DBX 160VU

therecordingart wrote: What do you think of Gyraf's 1176?

The G-1176 is a fine compromise to a DIY project
... worth the build
additional info
HERE
output transistor choices

The Purple Kit (is it still available ?) is the meat-ier discrete output with trafo and can easily be made into the 76 to 77 ... ask Andrew for details.

I don't have a Bloo but am considering getting a complete kit from Steve just so I can do a write up on the Factory site.
Lots of DIY LA2s out there to try ... PCB, Turret and PtoP

and YES we have DIY T4B's as well
various methods and parts choices ... all different ... with different results that various people do swear by.

and for RemyRAD

I was trying to keep things simple and electroluminescent is such a long word.
the old Tech Talk and Group DIY right here at RO (had)
and now the new Group DIY (the LAB) have much info of DIY T4B's and the various methods of grading the LDR's and use of the Nite Lites or purchase of raw panel.
We spent much time on this and was ultimately a part of the krunch that took out Tech Talk.
Yes the LA3 is cool and we had a DIY write up on that all around the time it came krashing down.
funny that project seems to have vanished and there now is a commerial re-issue available ... ( I wonder ... :roll: )
Yes and there was talk of the transistor mis-bias deep inside the UA1176 .... :shock:
oops ... shut up Kev
and repeated in later production runs
SHUT UP Kev !!

I didn't mention the LA4 and other LED/LDR and various Vactrol combos so I'm not really sure where my inaccuracy was ?
The Group DIY site had near 20meg of data on this stuff and that's a little hard to put into one very short little post.

back to the topic of choosing a good comp
For those interested in the 1176 I think UA still have the history page.
Tracks the model line up of the 1176 through the LN and Black and Silver faces
It's not enough to just say I have a Black Face 1176
so be careful when on E-bay.
just don't get me started on API
... but at least Paul has other things to occupy himself now ... 8)
all so very cryptic - Kev
or the 1066 to 1081 line
woops OT again !
:shock:
shut up Kev

I wish I had bought a Crane Song Trakker when I had the chance.
I was offered one right at the beginning when the company wasn't known and the priced offered was insane .... :roll:
At the time I said
wot's this crap and waved the hand
Silly Me !!!!
I should have taken the time for so research and an email to Dave.

One of many I have let slip away
....... but you get that
:cry:

RemyRAD wrote: ...The other optical limiters out there frequently use LEDs with light-sensitive resistors, or VACTECs, which have totally different ballistics to the electroluminescent panels and thus has a completely different compression characteristic....

Hi Remy,

I read a similar statement of yours to the one above in another thread (which has been locked so I could not reply). Please do not assume ALL modern optical compressors use the Vactrol element. When designing the Buzz Audio SOC-1.1, the performance of the Vactrol did not sound right to me, so we make our own LDR/LED module for this task. It comprises of a 4 LED light block shining onto 4 seperate Light Dependant Resistors (LDRs) with a differential drive system.

You are correct in that the electro luminescent light source reacts differently to LED's in that the LED is a lot faster to turn on and off. However, the LDR's themselves are inherently slow to react and tend to dominate over the light source.

In the SOC-1.1, the sidechain has been designed (in AUTO mode) to react in a similar nature to the electro light source used in the older opto compressors. In addition, we have a unique little circuit that fools the slow LDR elements to be faster when switched to fast attack mode.

Just wanted to clarify this.
Thank you
Tim.

Hey Tim, nice to see you here. :D

yep
be nice to Tim and he may visit us more often

when you want to know what's inside the box, guys like Tim and Joe M will give you a modern professional view and opinion.

Yes they have their own boxes to sell but deep inside they have a DIY streak and an keeness to share when they can.
We are blessed with a couple of others like DanK JohnH and FredF ... so keep your eyes open for the little gems of wisdom and experience.

Hey Tim!

That's pretty cool information! When I purchased my pair of LA3s, I got them for an insane low-price, $400 US for the pair, 14 years ago! I was told they had been "highly modified" and were now also transformerless..... I thought to myself "dammit, somebody trying to reinvent the wheel again!" I opened up the cases and discovered some fool had stuck in a small circuit board with a 5534 as the input! But still in the box was the original transformer! The funny thing was, the 5534 output was connected to the input of the input transformer! Voila, transformerless! LOL! I quickly removed the 5534. That was actually a good modification for people using consoles that could not drive a 600 ohm load out of their inserts. I was very lucky in that the original input transformers were no longer available at the time. Probably also another reason why on the 1176 later units, they went with a 5534 input stage, instead of the original UTC "ouncer" transformer which also required a hefty driver since it was a 600 ohm input too. All this because of crappy consoles! tsk tsk tsk

My used LA3s did not sound like the other LA3s I had worked with in the past. So, I opened up the T4B and what I found was 4 LED's in place of the electroluminescent panel along with a couple of RadioShack light-sensitive resistors in addition to the original ones still within, similar to what you described. I rebuilt my 2 units, the way I described and also consulted with the folks at UREI before they were handed off to Harmon industries. That was about 14 years ago. I already had a pair of silver LA4s and so did not need another pair of LED units. I've been quite happy with the LA3s ever since.

Hey Kev!

I found your link very interesting about the DIY 1176. I have one original 1176 LN, that's 30 years old! It has that original class A output, with the original transformer, with the tertiary winding. It sounds considerably different from my newer 1176 silver faces which has the push-pull output and a conventional transformer. Still cool but I do love the old blackface LN. I really wonder what Bill Putnam Jr. has done with the newer units?? I haven't really looked into them. I also have some old Neve limiters whose circuitry appears very reminiscent of the 1176s i.e. FET across the input as a variable resistor, with a peak detector circuit. Hey, does anybody remember the trick of pushing all 4 of the buttons, together on the 1176? Definitely cool sounding once in a while.

I hope all of this blather has provided some historic insight to those folks looking for compressor/limiters, either new or vintage?? (I'm glad I don't have to make up my mind about purchasing any new units lately)

Shop talk is fun!
Remy Ann David