The Marantz 3300 is a early line-up separate Pre-Amp released in 1973 with similar concepts thru the 33XX series including 1200 Af stage designs.
Power Supply
The 3300 uses a simplified single full-wave bridge rectifier and NPN/PNP regulated dual -/+B output supply for the tone/phono stages throughout.
The full-wave array was update to Vishay Axial ultra-fast, soft recovery diodes. Both NPN/PNP TO-39 devices were replaced with modern, reliable Central Semi-Conductor type devices. As with most axial I come across I replace these with a more reliable radial package device. All the electrolytic capacitors were replaced with high temp (105C) low impedance PW Nichicon capacitors with an increase in operating voltages and DC decoupling values for better filtering.
BEFORE
AFTER
Vdc -/+ Confirmation
RIAA EQ (Phono)
The onboard phono/mic stage enables a standard 40dB gain stage. Starting with a non-inverting, cap coupled input differential gain amp, then proceeds thru the RIAA inverter and cap coupled output stage.
All small signal devices were replaced with modern, low noise TO-92/TO-126 Fairchild devices and high gain ZTX devices.. Input/Output films were replaced with high grade Nichicon polypropylene capacitors. Remaining electrolytic type were replaced with low impedance PW Nichicons with an increase in operating voltages. Remaining ceramics were replaced with a high grade WIMA polypropylene type.
BEFORE
AFTER
RIAA Curve Response
X10 (Times Ten) Amplifier
The initial gain stage enables a nominal 20dB gain boost via a non-inverting design with negative fb. The X10 stage utilizes a Hi/Lo filter cap coupled feature at standard 3dB points.
The input films were replaced with a high grade Nichicon polypropylene film capacitors. Additional small value MFD were replaced with a high grade WIMA polypropylene films including ceramic capacitors. Electrolytic capacitors were replaced with low impedance PW and audio grade KT/KA Nichicon capacitors with an increase in operating voltages. All small signal devices were replaced with modern, low noise Fairchild devices and high gain ZTX devices.
BEFORE
AFTER
Tone Amp
With a simplified gain stage of the X10 design, the tone amp is a inverting, unity gain OP concept with a Bass/Treble feature.
Similar to above; the input films were replaced with a high grade Nichicon polypropylene film capacitors. Additional small value MFD were replaced with a high grade WIMA polypropylene films including ceramic capacitors. Electrolytic capacitors were replaced with low impedance PW Nichicon capacitors with an increase in operating voltages. All small signal devices were replaced with modern, low noise Fairchild devices and high gain ZTX devices.
BEFORE
AFTER
New high-grade WIMA polypropylene films installed in the Main Potentiometer PCB and all controls cleaned and treated with Caig Lab products.
AUDIO NOTIZEN
Excelente trabalho Sr Noah Schumacher. Parabéns!!
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