Friday, November 28, 2014

Marantz 2220B Receiver

Marantz 2220B

This is kind of a touch and place restoration, with selective boards. A nice open model to work on, with a symmetric amp PCB. Was quite blown away by this little model, though Im not really a B variant fan. 

P800 Power supply
I've been really favoring the Panasonic FC's and FR's now in the power supply, their robust, and rated well. H803/H804 the 131B/ 132B diodes were replaced, the 131 with a common cathode MUR1620 and the 132B with two UF4005 common anode.. H808 s1b-01-02 was replaced with a s ingle UF4005. Voltage was adjusted at J811 & J812 @ R808 to 35VDC.

P700 Amp Board
All the lyrics here were replaced with either Silmic II's or FG's. H705/706 MV13 were replaced with two 1N4148 diodes in series and shrinker, and the differential pair of H701-H704 were replaced with matched KSA992's, greased and shrinked.
This unit is literally so pristine I even doubt its seen many hours judging by the switch and relay, so the relay here was only cleaned at the contact, but its a LY-02 Omron type. Set idle per channel at 20.4mV Left and Right with offset at 0.04 L/R and stable as can be. Runs quite cool even at an hour or two.

P500 Tone Board
Lytic's here are Silmics II's, at CE23/24 Nichicon MUSE ES bipolar are used. With WIMA MKS2's used at CE19/20 and CE 21/22.

P400 Phono
Lytics again here were replaced with all Silmic II's, the two tantalums C401/402 were replaced with WIMA MKS2, the BJT's here are fine as is.

New mica and thermal compounds were applied along with a new EG1018-ND dpdt switch with a vishay X1Y2 safety cap.


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