Marantz DAC-1

Commentary

This is a digital audio control amplifier with the purpose of limiting the music source and displaying its power.
Audio signals that pass through a D/A converter after PCM processing such as CD a D/A converter contain a large amount of noise (out of audible frequency band noise). This was developed based on the idea that a signal without this noise is sent to a power amplifier.

The input stage is equipped with a low-pass filter based on the CD technology of the Phillips-Marantz Group. This filter allows only signals below the sampling frequency to pass and suppresses intermodulation caused by high frequencies in the amplifier section.

By providing a buffer amplifier in front of the master volume, it is possible to use a low-impedance volume and to reduce noise level fluctuations caused by volume position.

It uses a trans-coupled multi-feedback circuit based on the output circuit used in the LHH2000. It moderately reduces unnecessary bands other than 20 Hz to 20 kHz and smoothly extracts only audio signals.
Furthermore, by providing a gain of + 14 dB, it is possible to drive the power amplifier with a margin.
Also, by installing an output transformer, we have succeeded in completely separating the chassis ground and the output system ground.

By adopting the dual winding method for the secondary winding of the output transformer, different 180 ° phase signals of positive phase output and negative phase output are output to Output 2. By using these two outputs, BTL drive of the power amplifier is possible (Marantz power amplifier only).
In addition, by using outputs with different phases, connection of absolute phase is possible.
Output 2 can be used to drive a positive-phase power amplifier in reverse phase or a negative-phase speaker in reverse phase.

In pursuit of the ideal sound quality, each part also uses parts that pursue quality.
Toroidal transformer is used for the power transformer and super permalloy core is used for the output transformer.
Non-magnetic gold plating is used for the input / output terminals. In addition, solid aluminum is used for the volume knob in order to prevent sound pressure energy from the speaker, which is said to cause resonance and vibration of the whole amplifier, especially the volume knob.
A flip-coated glass epoxy substrate is used for the printed circuit board to improve insulation resistance.
In addition, a non-magnetic copper-plated chassis is used for the chassis, an 8 mm aluminum front panel and two 1.3 kg die-cast side panels are used to reduce resonance, and a 4 mm aluminum top cover is used to reduce squeal.

It inherits the design philosophy of the output transformer of LHH2000 and can be combined with the digital line TRANSFORMERS DLT-1 for reproduction.

Model Rating

Type	Control amplifier
Input Sensitivity / Impedance	300mV/47k Ω
Rated Output / Impedance	1.5V/50 Ω
Total harmonic distortion rate (20 Hz to 20 kHz)	0.03%
Signal-to-noise ratio (A curve)	110dB
Power consumption (Electrical Appliance and Material Control Law)	8W
Pwer	100 VAC, 50Hz/60Hz
External dimensions	Width 250x Height 84x Depth 211 mm
Weight	4.2kg