DIY Audio 1: OLA5-DIYRE
Born from the ashes of the Urei LA-4, this is DIYRE's first foray into the world of opto compressors. Ever since college I have been a following their work. Unlike the other kits of theirs I have built, this little guy had a lot more component density and some handy design work.
If you look up on their page you'll see the whole reasoning to why they chose the LA-4 instead of the LA-2A or LA-3A, but either way I was pretty interested in the LA-4 as I have used them on multiple recordings. They are pretty nice compressors just lacking a bit of character and sound slightly veiled. And since only the compression portion of the circuit is based on the LA-4, the DIYRE was able to upgrade the gain stage. I went for the transformer output instead of the op-amp based output because I was really hoping for a bit of distortion from this guy. For the DOA I chose one of the CAPI 2520s, mostly because I had one built already and lying around.
Firstly, the build was simple, it's a decently dense pcb and it took some time filling in all of the components, but their layout makes this pretty easy. Follow the instructions for sure (I jumped ahead on the LED portion and had to redo some steps, so follow the instructions...). The hardest part was definitely soldering the DOA, which you can opt for a IC op amp instead. Once completed I fired it up and ran through the tests and then I thought I had messed something up. I was noticing a lot of gain staging problems, I was metering the wrong level on the input back into pro tools. There goes $300 bucks right?
Turns out I was wrong... about being wrong? Went back and forth a bit with Peterson Goodwyn (by the way awesome guy, super helpful about everything) but I ended up figuring out that it was my summing mixer. The passive Folcrom RMS216 actually was causing the level to be slightly different than where it should be. Once I wired the output directly into the Orion 32 it was working perfectly.
Ok on to the sound...
First off, the compression characteristics. The attack is decently fast too fast for snares or kicks, but vocals and instruments like sax or bass sounds good (I bet it would do real nice on room mics actually). The limit function hits pretty hard. If not dialing compression in and flipping the standby switch you can hear a bit thicker low-mids, which I am guessing is from the trafo. When you push it hard the OLA5 it breaks up a in a nice way, it is transistor based distortion with a bit of transformer distortion sprinkled in. I would say its a pretty musical compressor, not loaded with character like its 3A brother, but unlike the LA-4 it isn't veiled. I'm excited to use it a whole lot more.