Stereo Pre-Amplifier
A high quality stereo Pre-Amp offering ballanced or unballanced outputs.
The volume & balance pots, input selector and signal path resistors are all custom ordered from the highly acclaimed TKD company (Japan) .
Signal path capacitors are WIMA metallized Polypropylene film throughout, and all opamps are “audiophile” Burr-Browns.
Hypex wide band voltage regulators are used for power supply, and an external mains transformer guarantees zero induced hum.
Input selector is located near input sockets for shorter wire runs.
RIAA equalization followed by subsonic “wow” filtering are both optional – components are channel matched to within 1% tolerance.
CMC-805-2.5-F-G gold plated RCA socket pair
The 7 RCA socket pairs (6 stereo inputs and one unbalanced stereo output) are CMC gold plated type.
The XLR socket pair (a balanced stereo output) is NEUTRIK.
NEUTRIK XLR balanced output socket
Pre-Amp layout schematic. The balance pot is connected in parallel with the volume pot, performing its task without leaving an imprint on sound quality.
If a dipole subwoofer is used, acoustic phase cancellation inevitably takes place.
In order to compensate for this phase cancellation, dipole equalization is required.
In a passive crossover system, dipole equalization is most easily accomplished within the pre-amplifier by means of a minor change to the op-amp feedback circuitry.
Dipole equalization circuit
The resultant pre-amp frequecy response
Aluminum case
front
