Friday, November 6, 2015

Aker's Marantz 2265B Receiver

Marantz 2265B Receiver 

Id like to showcase this rebuild. I was extremely happy with how it turned out, cosmetic and performance wise I was just blown away. both hi and low level stages are crystal clear yet pronounced for each input. I really like the high level stage for line level devices such as my MicroMega CDP. I was lucky enough to have a Thorens TD160 to audition this with as well :)

This is an Audiokarma members unit, Arrived in quite dirty shape with oil smudges all over the faceplate and finger mares. Also noted was the unit was stuck in protection with a host of driver issues.  In this case the 3rd stage drivers and final output devices were shorted along with the bias array resistors. All new outputs were ordered for this overhaul.

Power Supply P800
The power supply is a little different here than in per-say the 50-70 22XX series. I would suggest attacking this board as one replaces the filter capacitors and removal of the driver stage, this allows you to contort the board in a open-book fashion. A new MY4 Relay was installed with OS cover, this particular relay is easy to replace in this supply as the tracing is easily accessible. All the lytics here were replaced with my standard high temp, long life rated Panasonic FR/FC capacitors. 

Also updated were the common Anode/Cathode devices. MicroSemi manufactures an extremely reliable 20A/200V Ultra-Fast TO-220P packaged rectifier to replace the originals. Its important, while your in here to remove the caustic glue used to support the larger lytics.

Driver (Single Topography) P700
Normally I'm not a big fan of the single topography PCB's like used in the 2265B driver stage, though in this case the layout is very symmetric and clean with totally separated rails and return, they way it should be done, if done, unlike per say the 2252B which houses the PS and Driver  stage all on ein PCB.

All the lytics here were replaced with audio grade Elna's and low impedance, high reliability Nichicon PW's. Differential pair transistors were updated to Hfe matched 992 BJT's and all general and rectification diodes updated to UF applications or general 4148 type. Also updated were glass pack diodes to 4148's soldered in series All new outputs and MICA were installed, reliable modern outputs cross referenced to MJ21193/94G devices.

The damage consisted of a shorted resistor at R772, the final stage Q759, Q757 was shorted along with outputs in that bank. 243G MJ' were replaced in the final stage along with 2690ays for the the Q757. 

New 35mm 10,000 microfarad CDE capacitors were installed these have been my best find since Panasonic THA's became less available. When the driver board is removed is convenient. They also share a common ground strap like many of the higher rated 22XX's do. I like to add the new EG1018 7A power switch and a Vishay X1Y2 safety capacitor after the filters to finish up on hardware. 

Phono P400
The phono here shares the same PCB as the switching control assembly as is in many later 22XX series Marantz, I prefer the stand alone PCB. Though they did get away from the faulty 458 transistors like the earlier models. All lytics here were replaced with low impedance, high reliability Nichicon PW's. I recommend reflowing the control connections at this time as they appear to suffer excessive torque from the switch when in use. Remember when replacing to save the leg dressings as a few lytics need to be contorted to allow for the shaft of the selector switch.

Pre-Amplfier/Tone PE01
I like these assemblies, not as easy to access as say the 2325 with that molex. All the lytics here were replaced with again Nichicon PW's and audio grade KA's by Nichicon, along with bypass polypropylene WIMA and coupling MKP polypropylenes. This is the perfect time to clean and treat phenolic based potentiometers as well. 

RF Stages
I really like how the main FM stage is accessible under the chassis, which makes recapping this section easier than most units as they typically sandwich these boards. In any RF stage, AM or FM I like to use the PW's again. Low impedance and very reliable they are perfect suitable here. 

I was very happy with how clean the faceplate and knobs turned out on this unit, Overall I'm quite blown away with the 2265B, after the overhaul it really sounds amazing, clear and precise are the two words that come to mind. 

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