Block diagram of the SUMMING-AMP-L+R board
The Sefirot architecture includes the following boards, all available in this webstore:
-
Super Balanced Input (SUPER-BNCD-INPT)
-
Baxandall Volume Control (BAX-VOL-CTRL)
-
Headphone Amplifier Stage (HEADPHONE-OPAMPLFR)
-
Bandwidth Definition & Subbass Low-Pass Filter (BWLP-FLTR-MONO)
-
Summing Amplifier Module ( SUMMING-AMP-L+R)
-
LLLL-INDICATOR Log-Law LED Level System (LLLL-INDICATOR)
-
Power Supply Module (PAMP-PSU)
The SUMMING-AMPÂ board integrates a summing amplifier that combines the left and right stereo channels, routing all low-frequency content to the subwoofer amplifier in a bi-amplification scheme. The board includes two independent buffered inputs, balanced outputs, and a unity-gain inverting summing stage, as shown in the block diagram.
The following are the main features of the SUMMING-AMPÂ board:
- Buffered input for both channels.
- No gain added to the original signals.
- Balanced outputs for independent-unaltered Left and Right channels.
- Summing amplifier with an inverted phase output signal.
- THD+N for independent outputs Left and Right: 0.00002% at 1 kHz and 0.00005% @ 10 kHz while driving a 600 Ω load, output: line level 1.23 Vrms (+4dbu).
- THD+N for summing Amplifier output L+R: 0.000016% at 1 kHz and 0.00004% @ 10 kHz while driving a 600 Ω load, output: line level 1.23 Vrms (+4dbu).
- Bandwidth: > 300 kHz for independent channels and > 450 kHz for summing amplifier.
- Frequency response of independent outputs: -0.06 dB at 20 Hz and -0.13 dB at 20 kHz.
- Frequency response of summing amplifier L+R output: -0.18 dB at 20 Hz and -0.13 dB at 20 kHz.
- Crosstalk: < -98 dB @ 1 kHz
- Input impedance: > 46 kΩ
- High-quality double-sided plated-through-hole PCB (Lead-free HASL) with solder mask on both sides and full screen print.
- Current consumption: 106 mA Max.
- PCB size: length=100mm, width=73 mm. It incorporates four M3 fixing holes.
A couple of interconnection diagrams to build a preamplifier using different boards designed by Olas Audio are displayed below.
Interconnection between different Olas Audio boards to build a preamplifier with two separate Low pass/Bandwidth Definition filters
Interconnection between different Olas Audio boards to build a preamplifier with one Summing Amplifier and a Low pass/Bandwidth Definition filter
The published price is for the PCB only. A bill of materials and assembly instructions will be provided upon purchase.
