Sydney Recording Studio LA2A Fire Up

Sydney Recording Studio

We are please to announce that our first in-studio built DIY LA2A was fired up and used in the Sydney Recording studio yesterday. It sounded fantastic. We used it to compress a lead vocal that had already been pre recorded. We simply sent the signal out, via our apogee symphony IO, into the new LA2A and back into the computer. There were a couple of modifications that we made prior to using it in the Sydney Recording studio. Firstly, we changed out the pots, and secondly, we swapped out the optical attenuator. Let’s elaborate on these details and how they have positively impacted our mixing capability in our Sydney Recording studio.


Originally, we had used PEC potentiometers for our gain and peak reduction dials. Whilst these did work, we found that the amount of gain that we were getting was far too great for the amount of pot rotation. Similarly, the peak reduction required far too much rotation to actually hear the peak reduction. As it turns out, the original units had used the old Allen & Bradley potentiometers. They made a huge difference the Sydney Recording studio unit. Both the gain and peak reduction stages were working as one would expect and they felt much better to use.

Optical Attenuators

The optical attenuator, or “opto”, is the hardest component of the unit to attain. We were lucky enough to purchase an original T4B opto for our Sydney Recording studio LA2A from the USA. It was extremely expensive; roughly $2000 Australian dollars for just the opto. We also purchased a new Kenetek Optical attenuator. These are designed for DIY LA2A’s. We were surprised at how much smoother the original T4B sounded when compared to the new one. This Sydney Recording studio investment was well worth it.

Transformers, Caps and Resistors

Our LA2A also has original UTC HA100X and A24 input and output transformers. These are similarly difficult components to find and the investment was extremely steep. The capacitors are all audiophile grade, large and extremely expensive. The resistors were overkill. We used Audiophile grade AudioNote resistors, most of which were large 2 Watt resistors.
Ultimately, the good sound quality is the sum of all the high grade components. I’m certain that our new Sydney Recording studio LA2A will be making wonderful records for many years to come.