
SK501 Single 500 Series Host
The SK501 is a single slot, 500 series compatible case and power supply.
The EQ531T is a 3 bands tube equalizer plus High pass filter, built around a dual triode, adapted to the 500 series of API*.
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The EQ531T is a 3 bands tube equalizer plus High pass filter, built around a dual triode, adapted to the 500 series of API*.
The tube, the midband inductor and the output transformer add a beautiful vintage colour to the EQ.
Just install it in your API* compatible LunchboxTM and start recording.
1: High frequency Sets the High shelf center frequency. 5 frequencies are available. The first position disables this band.
2: - dB + Sets the amount of cut or boost of the High shelf, up to 12dB.
3: Mid frequency Sets the Midband center frequency. 5 frequencies are available. The first position disables this band.
4: - dB + Sets the amount of cut or boost of the Midband, up to 12dB.
5: EQ IN Activates the EQ.
6: Low frequency Sets the Low shelf center frequency. 5 frequencies are available. The first position disables this band.
7: - dB + Sets the amount of cut or boost of the Low shelf, up to 12dB.
8: High pass frequency Sets the frequency of the High pass filter. Continuously variable from 15Hz to 400Hz.
9: HPF Activates the High Pass filter.
Absolutely everything!
You bring the solder (use good quality solder, 1mm diameter max) and the Lunchbox.
The EQ531T kit is a medium difficulty build.
Measure | Conditions | Value |
Iddle supply current | No input signal | I = +/- 165mA |
Input impedance | f=1kHz on XLR | 22kΩ |
Maximum input level | on input XLR | +27dBu |
Maximum output level before clip | on output XLR | +28dBu |
Frequency response graphs |
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DOCS Code | Documents |
From DOCS-24 | Parts list Components layout Assembly guide Setup guide Schematic |