Marantz - 4140 - Stereo - Quadraphonic Solid state amplifier

Very rare for sale integrated Marantz 4140 Quadruple
- it's a true collectible piece fully restored.

New!
The rectifier diodes u11c and u12c were replaced with ultra-fast modern diodes, each with a snubber capacitor to ensure a pristine power supply!

For sale, an exceptional Marantz 4140 integrated amplifier, a true legend of the “Silver Face” era,

! Sold with its rare SQ Marantz SQA1 decoder!

This unit has benefited from a complete restoration aimed at surpassing its original performance while ensuring reliability for the next 30 years and preserving the classic Marantz sound signature.

This is not a simple repair, but a total audiophile reconditioning.

Technical restoration details (Components)
1. Capacitors (Total recapping): All electrolytic capacitors have been replaced. Brand choices favor performance and musicality:
Power Supply: Major upgrade with 22,000µF Nippon Chemi-Con capacitors (an enormous capacity for exceptional dynamics and bass control).
Audio Circuit (Signal Path): Audiophile Nichicon MUSE, FG (Fine Gold), and FW capacitors, known for transparency and harmonic richness.
Power and Decoupling: Very low-impedance, long-life Panasonic FM and FC capacitors.
Connections: WIMA film capacitors for surgical precision at high frequencies.
2. Transistors (Reliability and Low Noise): Obsessive attention to transistors to guarantee absolute quiet operation:
Hum reduction: Replaced the notoriously noisy and leg-worn 2SC458, 2SA640, 2SC733 transistors with low-noise modern equivalents Onsemi KSC1845 & KSA992.
Safety & Stability: Unstable transistors (2SC1451) and aging standards (2SC945) on the power boards were proactively replaced with robust Onsemi models (KSC2690/KSC2383).
Relay replaced by a modern low-noise relay.
Input stage: Differential pairs replaced by matched transistors for perfect DC offset stability (0V).
3. Calibration & Maintenance:
Cleaning of potentiometers, switches and contacts (DeOxit).
Complete bias and DC offset adjustment to factory specifications.

Aesthetic & Functional Condition
The amplifier is in superb overall condition. The brushed aluminum front is very clean and the iconic blue illumination is fully functional. Ready to use (Plug & Play).

Shipping is of course possible anywhere in Europe! Just ask me.
I’m used to shipping; I build ultra-strong packages! Will be shipped with insurance.