The API Select TranZformer® CMP incorporates API’s legendary VCA-type compressor circuit into a versatile and compact guitar effects pedal. Designed to easily fit into your pedal board and engineered to run off standard 9V power supplies, the CMP gives you classic studio-quality compression right at your feet. Other features include a buffered bypass in/out footswitch, adjustable attack and release times, wet/dry blend control, selectable “feedback” and “feedforward” compressor styles, transformer output, and of course the classic API sound.
Features:
•Proprietary API 2510 OpAmp
•Signature API output transformer
•Adjustable attack and release times
•Wet/dry blend control
•Selectable feedback/feedforward compressor styles
•Buffered bypass
The API Select TranZformer® CMP provides unsurpassed sonic sculpting by incorporating key elements of a legendary API 527 VCA-type compressor circuit into a versatile and robust guitar effects pedal. Features include a buffered bypass in/out footswitch, adjustable attack and release times, wet/dry blend control, selectable “feedback” and “feedforward” compressor styles, transformer output, and of course the classic API sound.
SIGNAL FLOW (from right to left): Input > Sustain > Blend > Transformer Output
AUDIO CONTROLS
INPUT: Input level; +9dB to +30dB; More gain creates more compression
SUSTAIN (compression): Determines amount of compression (gain-reduction); Higher levels provide more compression (lower threshold)
BLEND: Mixes the dry (uncompressed) signal with the wet (compressed) signal.
OUTPUT: -inf. to 0dB output level control; 0db (no cut) is fully clockwise
SWITCHES
A. ATTACK: Sets the compressor’s attack time to either FAST (1ms) or SLOW (10ms) B. RELEASE: Sets the compressor’s release time to either FAST (300ms) or SLOW (1s) C. TYPE: Selects between feedback (OLD) or feedforward (NEW) compression styles
D. BYPASS: Buffered bypass footswitch
E. Indicator LED is illuminated when pedal is engaged
CONNECTIONS
1. INSTRUMENT INPUT: 1⁄4” hi-Z (1MΩ), unbalanced
2. POWERINPUT: Uses 9V to 18V DC Negative
Center 2.1mm x 5.5mm barrel connector
Do not use more than 18VDC
3. OUTPUT: 1⁄4”, unbalanced
SETUP
- Apply power using an external power adapter (sold separately) or an output tap of a pedal board power distribution system.
- Plug a cable from the instrument output into TranZformer CMP INSTRUMENT INPUT.
- Connect the OUTPUT to an amplifier input or the next pedal in your chain.
USE Starting settings: Engage footswitch, set INPUT, SUSTAIN and OUTPUT controls to 12 o’clock and WET/DRY control fully clockwise (WET).
- Adjust INPUT to set input level to the compressor; Higher input level creates more compression at a given SUSTAIN setting; Reduce INPUT to avoid clipping if needed.
- Set SUSTAIN as desired for increased compression, perceived loudness, and punchiness.
- Adjust the ATTACK and RELEASE controls; A FAST attack setting begins compressing the louder signals sooner and a SLOW attack time takes longer. A FAST release setting quickly stops compressing the louder signals whereas a SLOW release time takes longer.
- Set the TYPE switch to either NEW or OLD; NEW mode uses feedforward compression and gives a more-modern compressed tone. OLD mode uses feedback compression and provides a smoother, more-vintage character.
- Adjust the BLEND control to set the final output mix; Moving the control clockwise towards WET mixes more of the compressed signal into the output. Moving the control counterclockwise towards DRY mixes more of the uncompressed input signal into the output signal. Fully counterclockwise is 100% DRY and fully clockwise is 100% WET.
- Set the OUTPUT control to achieve the desired final output level going into the amplifier or the next pedal in the chain. (NOTE: Does not reduce clipping of internal signal.)
Input connection:: 1/4" Hi-Z unbalanced instrument input
Input impedance: 1MΩ
Bypass: Yes, buffered, 0dB
Output connections: 1/4" Hi-Z unbalanced output
Output Impedance: Hi-Z output: Less than 1kΩ
Input Gain Control: 9dB – 30dB, Variable
Output Level Control: -inf. to 0dB, Variable
Maximum output level before clipping: +15dBu (9VDC) +22dBu (18VDC)
Frequency Response: +0dB, -1dB, 20-20kHz
Compressor: Ratio (Sustain): Varies from 1:1 to 20:1 depending on compressor control setting.
Attack (switched): FAST (1ms) or SLOW (10ms)
Release (switched): FAST (300ms) or SLOW (1s)
TYPE (switched): New (Feed-forward), OLD (Feed-back)
Power Supply: 9-18VDC @ 100mA
Size: 4.6" x 3.8" x 3"
Size (Boxed for Shipping): 6" x 4.5" x 4.5"
Actual Weight: 1.5 lbs.
Shipping Weight: 2 lbs.
