Vintage Marantz 2385 receiver – it is working but …… volume level control is uncontrollable after 50% . On 50% volume – 200w Sansui 3 way control speaker starts jumping high. Base speaker constantly pops up loud. Sound distortion . Most of sound spectrum in lower range, sounds similar to 50 years tobacco smoking guy singing in karaoke bar.
Customer purchased this unit online after ” FULL RECAP” popular new days service. Unit doesn’t have original Marantz classic softness and vintage sound spectrum. You do NOT HAVE TO BE MUSICIAN TO HEAR THAT.
All capacitors in driver, output section and filter section has been changed to new (HARD TO TELL WHAT BRAND). All PNP transistors in preamp / filter/ phono section changed to 2SA733 and similar modern NPN transistors.They have similar parameters but completely different characteristics, usage limitation and more.
Changing 1 or 2 of them will not change whole picture but massive replacement will change Marantz to something between Onkyo and Toshiba/Sharp hybrid unit not capable for adjustment and out of full spectrum frequency response.
Basically someone did a massive components replacement spending 4-10 days just to destroy original Marantz. They call it “full recap”service. It was full funeral service for Marantz in real life.
We spend 3 days to “RE-RECAP” job on this unit and change transistors and caps to originals. 26 capacitors and 11 transistors. Everywhere except power supply section. We can call it Marantz again and it sounds like Marantz.
For all folks who is doing this – PLEASE, DO NOT TOUCH ORIGINAL CAPACITORS AND TRANSISTORS UNLESS THEY ARE BAD. THEY WERE INSTALLED WITH UNIQUE ENGINEER IDEA AND KNOWLEDGE IN CIRCUITRY DESIGN. ALL THOSE CAPACITORS AND TRANSISTORS ARE CRITICAL COMPONENTS IN SOUND FORMATION AND AMPLIFICATION PROCESS.
YOUR GOAL IS TO REPAIR AUDIO UNIT DOING MINIMAL CHANGE TO ORIGINAL DESIGN. YOU ARE NOT NEW MARANTZ CREATORS.
Analog audio equipment is components sensitive device. Massive, no sense full recap and transistors will change and destroy sound spectrum, texture and parameters completely. Only one area where full recap is possible and necessary is power supply section.
We hope this article will help to save some audio equipment from destruction called FULL RECAP.