UREI LA-4 by ElectroNick
This is a review of the Urei La4 blackface. Note that there is differences between the Urei La4 blackface and the Silverface version, the blackface been the first and original version.
Some facts :
The topology of the Urei La4 blackface and the silverface are differents :
The Blackface use 2 X RC4136 chips in his topology, the Silverface use 3 X RC4136.
The Blackface have a better quality VU Meter than the Silverface.
The Blackface have big ELKO capacitors in the power supply and not the Silverface.
The Urei output transformer number might be different in the early Blackface and the later Silverface unit.
There is 3 differents La4 unit :
1- The original La4 blackface
2- The original La4 Silverface
3- The later La4a Silverface
The Review :
The one thing i like about the Urei La4 blackface is that it does not mess with the bass content of the audio program and that is something that not all compressors offer. It is a clean Leveling amp that can give you some super natural compression and also add some glue to a mix or some grab in the upper mid of a signer or an electric guitar.
The controls on the La4 are really simple but in a really complex way. You will need to play and experiment with it to get used to the palette of sounds you can create with this unit. The one thing that is super important to understand with La4 is that the gain structure before hitting the compressor have a big impact on the sound and how the compressor react. There is only a threshold, output volume and ratio to control the sound but don't forget about the hi and low switch in the back, using that and playing with the gain structure before hitting the La4 will give you a clean or saturate sound, a fast or a slow compresion mode. There is a red light in the front of the unit that indicate went the input is saturated so you will know that if the light go in the red you are in a slow mode of compression. If you want to be in a fast compression mode you should not see the red light glowing so it is very important to build your gain structure in front of the unit in consequence of what kind of compression caracter you want to acheive...
There is a lot of modifications possible with this unit. I've wrote in a gearslutz forum about all the modifications i did to mine so you should follow thoses and many more if you want to lurn more about mods and enter this territory...there is a lot of options and lots of peoples offering differents mods but i can tell you that if you have a solder iron and a screw driver you should be able to do all of them by yourself and lurn in the process.
The La4 is a perfect all around compressor/limiter. Just let me tell you here that there is nothing that the La4 cannot do, big thank you to the low and hi impedance switch in the back of the unit. You can use the La4 as a DI with great results, you can used balanced or unbalanced line and you can even use the unit as a mic preamp (using a hi output mic like a tube mic) with or without modifications. Since the unit is super clean it will work well with all kind of material and there is nothing you cannot throw at it, super great all around unit and first compressor to get !
The bang for buck here is enormous cause La4 is the cheapest Urei leveling amp available and is also the cleanest. If you want a compressor with a sound or a compressor to pump and smach your drumkit look else where but if you are looking for a super clean tracking compressor a leveler for mixing to give some grab or pressence to your voices and instruments...or maybe you are looking for a stereo buss compressor for your drumbuss or Master buss at mixdown, here's your ticket !
I want to point out that the blackface unit don't suffer from the slow slew rate peoples are talking about from the silverface unit. In fact i can use more than 15db of gain reduction and not affecting the hi freq in a bad way. I tend to use a lot the 4:1 ratio compression with around 15db of gain reduction...it seem a lot but the unit is so transparent ! The 20:1 ratio give you a pretty agressive sound that can be helpfull to beef up some track. The 2:1 is the most natural and neutral setting of course, it's like only using a fader almost... I use the 2:1 ratio when i use the La4 as a mic preamp with a tube microphone and to help out with very dynamic signer or screamer don't worry, even if it goes to 20db of gain reduction in the way in it will sound natural and sit perfectly in the mix without any artefacts or bad peaks.
I would say that the La4 is the perfect first compressor to get cause it's still cheap, it will handle anything to throw at it, it does not mess with the bass content and that is very important in modern productions like Rap or Danse music but most important it will make anything you throw at it sound better and bigger !
If you have any question you can PM me,