Project Description

  • Three HPF frequencies.
  • THD function that adds more even harmonics.
  • Grab function that selects a harder threshold knee.
  • Blend control for parallel compression.
  • All controls stepped for easy recall.
The BC1-THD provides smooth bus compression that applies for both mixing and tracking.
Engineers call it “The Magic Glue” when the BC1-THD’s  transparent compression strengthens mixes without compromising clarity.
The built-in blend control makes it easy to apply parallel compression by adjusting the blend of dry and compressed signal. A switchable sidechain filter can be applied which makes the BC1-THD less responsive to low frequency energy. The THD function adds more harmonics to the signal and the “grab” mode selects a harder threshold knee on all four ratio settings. Smooth and transparent compression will never go out of fashion.

Frequency response: 20Hz to 20kHz less than -0,025dB
Frequency response: 20Hz to 80kHz less than -0,3dB

Blend control fully CW (dry)
THD+N @ 0dBu: less than 0,0045%
THD @ 0dBu: less than 0,001%
THD+N @ +26dBu: less than 0,02%
THD @ +26dBu: less than 0,02%
Blend control fully CCW (straight)
THD+N @ 0dBu: less than 0,00045%
THD+N @ +26dBu: less than 0,0003%

Input impedance: 20kohm
Output impedance: 50ohm
Max input level: +26dBu
Max output level: +27dBu @ 600ohms load

Threshold: -20dB to +20dB
External sidechain: in/out
Ratio: 1.5:1 / 2:1 / 4:1 / 10:1 /
HP Filter: 80Hz, 150Hz, 220Hz, -6dB octave
THD: adds more even harmonics
Grab: selects a harder thres hold knee
Attack: /0.1/0.3/0.6/1/3/6/10/30/60/120mS
Release: 50mS/100mS/300mS/600mS/1.2S/Auto
Gainreduction meter
Make-up: 0 to +20dB
Dry signal mute
Blendcontrol: from dry to compressed
Compression in/out
External sidechain input: unbalanced TRS jacks
Internal, regulated powersupply with a toroidal transformer
115 or 230V, selectable

Specifications and components may be changed or updated without further notice.

“I own a BC1… awesome comp. My go-to bus comp. Kills everything else that I have tried. Thanks!”
John Kerns / Australia (No Doubt, INXS, Bruce Springsteen…)

“The TK BC1 has now become my first choice when I want compression on the stereo mix bus. I love the sound and really like the blend control.”
Terry Manning / Nassau, Bahamas (Shakira, Lenny Kravitz, Shania Twain, Norah Jones, Boz Scaggs…)

“I’ve been using the TK BC1 as my main drum compression on recent mixes I’ve done for Eric Clapton, Nikka Costa and Sheryl Crow. The mix control is the key. From letting the signal breathe or to slamming it to the wall it still allows the
original transients and character of the sound to be heard. It’s also a great stereo bus compressor. So now I need to buy another one! Another winner from Thomas Kristiansson.”
Justin Stanley / USA (Sheryl Crow, Eric Clapton, Beck, Nikka Costa, Mark Ronson, The Vines, Baby Animals…)

“Absolutely fantastic!!!!! Really punchy!!”
Jonas Quant / Sweden (Kylie Minogue, Hurts, Sophie Ellis-Bextor…)

“The BC1 is literally amazing! I am stunned… HUGE sound, so punchy, so gluey… anyway, I’m totally stoked. It is just what this mix needed :)”
Tre Sheppard, Onehundredhours / UK

“The BC1 is sensational!!!! BC1 is doing magic to kick and snare/clap inside a mix, without changing the character of the mix itself.”
Georg O Luksch, Home Music Studio / Vienna, Austria

“I used my new BC1-S for mixing and now I get the hype about it. I´ve tried using my other compressors but no one came even close to the BC1-S when using it on the masterbus. The sound got more bombastic and glued together. Big thanks for a magic box.”
Tobbe Karlsson, Boost Studio / Sweden

“Probably the greatest drum compressor I have heard! Gonna need to get some more I think!!”
Ben Hammond / UK (Saxon, Deaf Havana, Young Guns, The Veronicas…)

“I am the very proud owner of a BC-1. I love the unit and use it extensively live and in the studio”
Jonathan Gardner / Sydney, Australia (Empire Of The Sun, Jet… )

After a tour with INXS John Kerns sent us this email with the settings he used and his thoughts about working with the BC1: Hey there Thomas, Just got back from South America w/ INXS….I ended up with the following settings on the BC-1, strapped across the insert of the output of my Digidesign
Profile console…
I have to say that it worked really really well, and made a difference that not only local system techs heard, but all others involved heard as well. The difference was night and day, and this BC-1 will remain on bus duties as for the foreseeable future regardless of which band I am out mixing. It simply glued everything together really nicely, and didn’t mess with the image as so many other bus comps seem to do. Great stuff!


Threshold: varied between 0 and +2 was cruising between 3-6db gain reduction, depending on how much I pushed vocals/solos….

Ratio: 2:1

HPF engaged

Attack: 3

Release: 1.2S

Make-up gain: around +3

Comp in

Blend: about 1 o’clock on the dial

John Kerns / Australia

This is how Harm Schopman uses his BC1:
“The BC1 has made a massive difference to the drum sound on this tour. The parallel compression makes for a fatter drum sound without losing out on the transients. On top of that, the BC1 adds a nice silkiness to the highs whilst also managing to make the kick sound warm and punchy at the same time. I love it and I just might have to buy another one for the guitars or the backing vocals – I’ll let you know when I’ve had a chance to experiment some more.”


Threshold: adjust to get around 6dB of gain reduction

Ratio: 2:1

HPF in

Attack: 1mS

Release: 100mS

Make-Up Gain: around 5dB

Comp In

Blend: around 60% compressed

Harm Schopman / UK (Ocean Colour Scene, The Killers, …)

BC1-THD Drum smashing with Jayce Lewis, Northstone Studios, Wales-UK

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