Record Before Modifying the Stam Audio SA-2A

Hello, this is Jooyoung Kim, mixing engineer and music producer.
Until a few days ago, I was planning to sell my Stam Audio SA-2A second-hand and purchase a product from a Japanese brand.

However, it didn’t sell easily, and with the sudden rise in the Japanese yen… So, I decided to modify the unit myself instead of selling it.

Identifying the Problems

Here are the issues I identified with the SA-2A:

  1. Dissatisfying Sound
    • Excessive saturation and dull highs give the audio a muffled feel.
  2. Gain Parameter Adjustment
    • The output volume only matches the original level when the Gain knob is significantly reduced.
  3. Peak Reduction Sensitivity
    • Compression only activates when the Peak Reduction is turned up considerably.
  4. Limit and Compress Switch
    • The switch works in reverse.

Initial Steps in Modification

Addressing Problems #2 and #3

  • Inside the unit, I found a variable resistor labeled A100K.
    • This logarithmic resistor seemed unresponsive at lower ranges.
    • However, since we perceive audio in dB, it made sense to use a logarithmic curve for the Gain control.
  • I decided to replace:
    • Peak Reduction with a B100K (linear) resistor (ideally A200K, but it was unavailable).
    • Gain with a lower resistance A50K resistor.

I placed the order for these parts and will replace them soon.

Fixing Problem #4

  • The Limit/Compress switch was simple to resolve—just unscrewed it and rotated it half a turn.

Investigating Sound Quality Issues

The core problem remained the sound quality. After extensive research:

  • I contacted Stam Audio for the circuit diagrams.
  • I emailed Cinemag, the transformer manufacturer, to get specifications for the input/output transformers:
    • Input: Cinemag CM-5722, winding ratio 1:5.
    • Output: Cinemag CM-2570, winding ratio (18:2):1 = 9:1.

While considering transformer replacements (e.g., Sowter), I found several insights:

  1. Cinemag’s CM-5722 input transformer is already highly rated and doesn’t need replacement.
  2. Discussions on Gear Space suggested that tubes or the T4 cell impact the sound more than transformers.
  3. A post from 2016 or 2017 on Gear Space mentioned that replacing a single input tube can significantly improve sound.
  4. A YouTube video comparing various 12AX7 tubes on a Marshall amp highlighted sound differences between tube brands.

From this, I concluded that the JJ Electronics 12AX7 (ECC83) used in the V1 position is likely the main culprit behind the sound I dislike.

Based on the video, the JJ Electronics tube produced a tone that immediately felt off to me.

Planned Tube Replacements

I decided to replace:

  • V1 Tube: JJ Electronics ECC83 with Mullard 12AX7, a sound I much prefer.
  • V4 Tube: JJ Electronics ECC83 with another Mullard 12AX7 for consistency.

However, due to unexpected expenses this month (e.g., AES membership fees, domestic conference fees, paper review fees, and repairs for another compressor), I’ll postpone the tube replacement until next month.

Side Discovery: DIY Compressors

While researching, I stumbled across a site selling DIY cases and PCBs.

https://collectivecases.com/

While there are plenty of LA-2A clones on the market, the PYE compressor clone caught my eye.

  • PWM-based compressors are rare, and even the clones are scarce.
  • The original units are prohibitively expensive.

Although the schematics look complex and sourcing components would require significant time and money, I feel deeply drawn to this project. Maybe someday, with enough budget, I’ll take it on.

For now, this concludes my record of the SA-2A before modification. Once I replace the tubes and complete further changes, I’ll share my experiences and the sound improvements in a follow-up post.

See you in the next update! 😊

Introducing the SSL Fusion Bundle and Its Limited-Time Discount (-92%, Until 12/11)

Hello, this is Jooyoung Kim, mixing engineer and music producer.

SSL is known for creating excellent plugins but rarely offers deep discounts. This time, they’re offering a significant discount exclusively on the Fusion plugins, so I wanted to share an overview of the SSL Fusion Bundle for those on the fence about purchasing it.

Findout SSL Fusion Bundle at Plugin Boutique

Purchasing through the link above supports me with a small commission, which helps me keep creating content. Thank you!

Now, let’s dive in.

What is SSL Fusion?

The SSL Fusion was introduced in late 2018 as a hardware unit.

This piece of gear falls under the category of enhancers, akin to the SPL Vitalizer or the Overstayer MAS.

It became quite popular due to its feature set and relatively affordable price. However, ever since the Fusion plugin series launched, I’ve noticed an increase in second-hand listings for the hardware on various marketplaces.

While the hardware offers unique textures, I personally don’t use it heavily due to the inconvenience of recall. Many might have switched to plugins for similar reasons.
Also, let’s be honest—printing and tweaking can be quite a hassle!

The SSL Fusion Bundle includes five core functions from the hardware (excluding the hidden “LMC” or Listen Mic Compressor feature). Personally, I was most impressed with the Transformer and Stereo Image plugins. Let’s take a closer look at each.

SSL Fusion Transformer

Click image to purchase SSL Fusion Transformer..! It’s really great!

The Transformer plugin replicates the hardware transformer circuit. Clicking the transformer symbol activates it.

  • Shine: Enhances high frequencies.
  • LF EXTND: Gently boosts sub-lows.
  • Amount: Controls the level of harmonic distortion.

In essence, it’s an enhancer that adds harmonics and high-end sheen. Right from the first test, it added pleasing high frequencies and harmonics, making it versatile for various tracks.

SSL Fusion Stereo Image

Click image to purchase SSL Fusion Stereo Image

The Stereo Image plugin recreates the stereo enhancer from the Fusion hardware.

It offers more than just a width adjustment by including Stereo Shuffling, which allows control over stereo imaging in low-frequency bands.

  • Shuffle: Sets the cutoff for low frequencies.
  • Space: Adjusts the stereo width of these frequencies.
  • Width: Adjusts overall stereo width using M/S processing.

If you’re hesitant about pricier alternatives like Leapwing Audio’s StageOne 2, this plugin provides excellent stereo imaging control, especially for modern music where low-end stereo imaging is critical.

SSL Fusion Vintage Drive

Click Image to purchse SSL Fusion Vintage Drive!

The Vintage Drive plugin adds saturation and harmonic distortion while increasing low-end warmth.

With subtle settings, the low-end boost is manageable, but when pushed, it creates a more aggressive drive. If you’re a fan of the Soundtoys Decapitator or Arturia Dist TUBE-CULTURE, you might find this plugin fits your workflow.

SSL Fusion HF Compressor

Click Image to purchase SSL Fusion HF Compressor

The HF Compressor is a high-frequency compressor.

  • X-Over: Sets the frequency range for compression.
  • Threshold: Controls the compression amount.

This plugin is particularly useful when high frequencies enhanced by the Transformer plugin need some taming.

SSL Fusion Violet EQ

Click image to purchase SSL Fusion Violet EQ

The Violet EQ is a shelving EQ, also available as a 500-series hardware unit.

Its FAT feature subtly boosts specific frequency bands when the HPF is set to 30, 40, or 50 Hz. Otherwise, it’s a clean and straightforward EQ with no added harmonics.

Final Thoughts

The Fusion Bundle is currently available for under $100 during this sale. Whether on a mix bus or master bus, these plugins deliver exceptional results.

Findout SSL Fusion Bundle at Plugin Boutique

Given the sound quality, I now understand why so many hardware units have hit the used market. It also makes me curious about the actual hardware’s performance—maybe I’ll get one someday!

I hope this overview helps those considering the Fusion plugins.

See you in the next post!

Basics of Mixing – 11.1 Enhancing Highs and Lows

Hello, everyone! This is Jooyoung Kim, mixing engineer and music producer.

If you’ve been following along with the previous posts, you already have enough knowledge to start mixing. The rest comes down to practice.

I skipped over automation because it’s something you really need to experiment with hands-on. Whether it’s volume automation or parameter automation, try as many creative approaches as possible!

Starting from Chapter 11, we’ll move into more advanced applications.

Today, let’s talk about enhancing the highs and lows in a mix. This content is based on my book Basics of Mixng.

Shall we dive in?

Enhancing the Highs

Boosting the highs? It’s pretty simple—just use an EQ, right?

But have you ever thought about which EQ, which frequency range, and how you should boost?

The image above shows the frequency response when using Slate Digital’s Fresh Air. It’s a popular tool for adding “airiness” to vocals.

The Maag EQ4, on the other hand, offers a different character.

Each EQ introduces varying amounts of harmonic distortion, which impacts how and when they’re used.

For example, the Air Band on the Maag EQ4 reaches up to 40kHz, a frequency far beyond the human hearing range (20Hz–20kHz).

Why does this matter if we can’t hear it?

Research dating back to 1991 suggested that sounds beyond the audible range can influence brain activity.

  • 1991 Study: High-Frequency Sound Above the Audible Range Affects Brain Electric Activity and Sound Perception.
  • 2014 Study: Frequencies of Inaudible High-Frequency Sounds Differentially Affect Brain Activity: Positive and Negative Hypersonic Effects.

The latter found that frequencies above ~32kHz significantly increased alpha-2 EEG activity (associated with a calm mental state).

Even if your session’s sample rate is 48kHz or 44.1kHz, boosting ultra-high frequencies can indirectly affect the audible range based on the Q-factor.

Of course, you won’t always need to get this scientific about it—experience is the best teacher here!

While boosting highs can create pleasing clarity, it’s important to avoid overdoing it. Excessive use can result in a mix that feels “floaty” and leaves no lasting impact after the song ends. Use it judiciously.

Enhancing the Lows

For the low end, you can use EQ, but there’s another option: the subharmonic synthesizer.

This tool generates ultra-low frequencies by synthesizing them based on an incoming signal. It’s often triggered by kick drum signals to reinforce their sub frequencies.

Personally, I’m not a big fan—it’s challenging to perfectly match the kick’s attack and timing.

Popular plugins include Waves’ Submarine, Brainworx’s Subsynth and Subfilter, and UAD’s Voice of God.

Hardware options like the dbx510 are also available, but if you’re on a budget, the free Bark of Dog plugin by Boz Digital Labs is a fun alternative.

While it’s best to start with well-recorded source material, subharmonic synthesis can be a lifesaver when the source lacks sufficient low-end.

That’s all for today. See you in the next post! 😊

Working on “Miwha” EP with Danny Boy

Hello, everyone! This is Jooyoung Kim, a mixing engineer and music producer.

Today, I’d like to share the story of an EP project called Miwha, which I worked on with a friend this past summer.

The EP was released on November 8th, so it’s already been nearly a month! I kept meaning to write about it here but had too much going on. Finally, I’ve found some time to share it with you.

About the Artist

The artist, originally known by his Korean name, Hanseong Kim, has been an indie band musician. For this project, he rebranded himself as Danny Boy and wanted to explore a new musical style.

He came across some of my past work and asked me to handle the production for this EP. We ended up working on a total of four tracks together.

The Production Process

  1. Initial Submission: The artist sent me rough Logic projects with basic piano chords, vocals, and song structures.
  2. Arrangement: I added instrumental arrangements.
  3. Recording: We recorded vocals.
  4. Final Touches: I handled vocal tuning, mixing, and mastering.
Initial Logic Project
Arranged and Mixed Project

Track Breakdown

Track 1. 귀엽게 입었어 (Dressed Cute)

The artist originally used Logic’s built-in Fender Rhodes virtual instrument for the comping, which matched the vibe perfectly. I decided to use Arturia’s Stage 73 V for the main tone.

Since the lyrics were playful, I kept the arrangement simple rather than overcomplicating it. Initially, I considered layering lots of vocal harmonies but ended up scaling back for a cleaner feel.

Recording went smoothly, and everything came together nicely.

Track 2. 네비는 왜? (Why GPS?)

This is my favorite track on the EP. 😊

The initial demo was a simple four-chord loop. To match the melody, mood, and tempo, I opted for a Japanese-style arrangement, breaking up the chords and adding more complex instrumentation.

I used string libraries like Musio and mixed it with either LASS or BBCSO for texture.

The artist gave me free rein with this one, so I even modified the song form. It was a lot of fun but also very time-consuming.

The vocal recording was particularly tricky. The artist’s voice had some harsh resonances in the high-energy parts, so I had to use a notch filter—something I rarely do for vocals.

Track 3. 미화 (Miwha)

This track was the hardest to arrange.

I wanted to add subtle swing or groove with 16th-note drums, but the artist preferred a straight 8th-note drum feel, so we stuck with that.

The song features both electronic and acoustic drums:

  • Trap-style electronic drums for the rap sections.
  • Acoustic drums for the chorus.

The artist had sketched out the basic chords with Logic’s built-in Wurlitzer piano, so I replaced it with Arturia’s Wurli V2.

The Bye Bye vocal chop in the intro was a fun accident—it was originally just a vocal ad-lib that sounded like “Bye” after pitch-shifting. It worked so well we decided to keep it.

The rap recording had its challenges since it was the artist’s first time rapping, but we made it work!

Track 4. 그럼에도 (Nevertheless)

This ballad-style track was relatively straightforward in terms of arrangement but took the longest to record.

With its slow tempo and vocally-driven melody, every line had to be carefully sung, especially since the lyrics in the first and second chorus differed.

Recording all the vocal parts left both me and the artist completely drained. We started recording at around 2 or 3 PM and finished the final track around 1:30 AM. This particular song alone took over three hours to complete!

Final Thoughts

The project spanned about two and a half months, from early July to mid-September. It was a whirlwind of a summer.

Since we were working on a tight budget, I handled most of the production solo. For the recordings, a director friend lent us his studio, where I used:

  • Preamp/EQ: HA-73EQ
  • Microphone: Peluso P87
  • Audio Interface: UA Volt1

I also brought my Nero monitor controller, reflection filter, stands, cables—pretty much everything. Looking back, I should’ve taken more photos of the setup.

This experience reaffirmed that even with an affordable interface, good input gear and recording conditions make all the difference. Honestly, in most cases, something like a Focusrite Clarett should suffice if the rest of the chain is solid.

That said, I understand why studios lean toward higher-end gear for versatility and reliability. If it weren’t for my summing mixer, I’d probably use simpler equipment too.

I had so many thoughts during the production process that I wanted to write down, but now that I’m finally writing this, it’s hard to recall everything.

Anyway, that’s it for today! See you in the next post. 😊