Marantz 2226B Receiver
The 2226B variant is a later adaption of the 2226 at 26Watt output, released in the late 70’s and a new cosmetic concept. This B variant like many utilizes a single symmetric main PCB for the regulated supply and main driver stage.
P700 Reg. Power Supply
The regulated power supply and integrated main-amplifier designs are incorporated into a single pari-symmetric PCB with a large shared heatsink on the 2226B. The regulated supply employs a single full-wave rectifier for a smoothed 14.5 & 35V +B source.
All of the electrolytic here were replaced with a high temp (105C), low impedance type PW Nichicon with several of the DC decoupling capacitors increased in MDF for better filtering. The rectifier bypass films were replaced with high grade WIMA polypropylene film capacitors and Nichicon PP type films. The voltage adjustment was replaced with a sealed, precision Bourns potentiometer. All of the small signal devices including the TO-220 regulator were replaced with TO92L devices for better dissipation and a robust OnSemi MJ TO-220 device with new Wakefield thermal compound. The single array diode was replaced with a ultra-fast soft recovery diode including both common cathode/common anode to state-of-the-art MUR series TO-220 rectifiers.
BEFORE
AFTER
Regulated Vdc Confirmation
Filters
The main -/+B supplies are established via a 4A full wave bridge rectifier on the shared heatsink assembly. Both of the 6800MFD filter capacitors were replaced and increased to 10,000MFD CDE computer grade filter capacitors.
BEFORE
AFTER
-/+B Rail Confirmation
P700 Main PCB PA (Drivers)
For the shared driver design the concept is shared amongst a few different Marantz designs using a unique output transistor pair.
Differential pairs were matched and unlike the original design, were thermally coupled together with quality Wakefield thermal compound. All other remaining devices including pre-drivers/drivers and current mirror were replaced with TO-92L type Fairchild devices with better dissipation.
Differential Pair Mapping
All the electrolytic were replaced new MUSE BP inputs and low impedance PW Nichicons with an increase in operating voltages. The output films were upgraded to MKP polypropylene film capacitors. new Bias/Offset adjustments with sealed, precision Bourns potentiometers and varistors replaced with standard 4148 type.
BEFORE
AFTER
Bias Confirmation
P400 Phono (RIAA)
A shared concept in my of the B series 22XX with the integrated Selector switch on board.
All of the electrlytic capacitors were replaced with KT audio and low impedance PW type with an increase in operating voltages, the DC decoupling capacitors was increased for better filtering. All small signal devices were replaced with modern, low noise TO92 Fairchild devices.
BEFORE
AFTER
RIAA Curve Response
PE01 Front End Pre-Amp
A quite unique integrated board for this PE01 design compared to many 22XX series including B variants. On this particular unit almost all the potentiometers were damn near seized and required extensive cleaning and lubrication procedures to free up clean, easy rotary movements.
All of the electrolytics were replaced with KT audio grade and the DC decoupling to a PW Nichicon type, all with an increase in operating voltages and increase in decoupling MFD value for better filtering. All the original mylar in path were replaced with a high grade WIMA polypropylene film capacitors. All new small signal devices with modern, low noise TO92 Fairchild devices.
BEFORE
AFTER
RF
On this single main RF PCB design all of the existing tantalum and electrolytic type were replaced with a low impedance Nichicon PW type with an increase in operating voltages.
BEFORE
AFTER
Lamps
All of the 8V fuse type including both meters were replaced with a multi-SMD warm white 8V fuse type LED’s.
AUDIO NOTIZEN
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