Hello! I’m Jooyoung Kim, mixing engineer & music producer.
Today, I’ll talk about what I did after the article, Record Before Modifying the Stam Audio SA-2A, and how sound changed.
First, let’s review the problems I encountered.
- Output gain is similar to input gain, when the GAIN knob is too low.
- Compression is started when PEAK REDUCTION knob is too high.
- It sounds so dull, like high frequency response is cut off
Otherwise, The Compress and Limit switch was positioned incorrectly. It was simply solved by wrench.
1) Potentiometer Changed..1
If you take off the cover of SA-2A’s knob, you could see a100k potentiometer at each parts. So, I thought that if I change a100k to a50k for gain knob, amount of change is more lower. Also, change a100k to a250k for peak reduction knob, compression would be change more earlier.
So I changed them first.
The green line is SA-2A hardware, the pink line is Waves’ CLA-2A.
It doesn’t seem bad at all! Otherwise, output gain is similar to input gain, when the GAIN knob is too low yet, I ordered A25K and A10K potentiometer too.
2) Vacuum Tubes Changed
I changed my 12AX7 tubes from jj electronics to mullard.
Frequency response and compression curve was not that different compared to jj electronics’. But it sounds much better than before. Harmonic distortion seems to have changed many aspects of the sound.
3) Changed Potentiometer Once Again..2
Upper image is a25k, The lower image shows the a10k potentiometer. You could see frequency response improved when the lower value of potentiometer is used! The problem isn’t solved but it sounds really good.
Red curve is UAD LA-2A Silver face, pink curve is WAVES CLA-2A, green curve is SA-2A.
Compared to UAD, it’s nice that it doesn’t add such an overwhelming saturation. And compared to Waves, I like that it doesn’t have that overly compressed feel.
I think it’s worth trying out more simple tools like this in the future. Next time, maybe an EQ or a Comp DIY kit…!
See you in next post! 🙂
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