Vintage Marantz 2270 Stereophonic Receiver, Recapped, Upgraded, LED
Item History & Price
| Reference Number: Avaluer:14790956 | Brand: Marantz |
This was purchased recently from a first-rate seller who had done extensive work on it and brought it up to "better than new" condition. See below for very, very detailed notes and description of what was done.It's exactly as advertised and sounds great, just not my cup of tea.
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Welcome!This listing is for a Marantz 2270 that has been near completely refurbished, rebuilt and recapped. Every board in the main audio circuit was worked on. The only boards not given a recap were t...he FM MPX board and the AM Tuner as the MPX board is fairly sensitive to changes and the AM Tuner works perfectly fine as is. This was upgraded and serviced as if I would be the one using it, however I have enough receivers already so this one gets to go to a new home.After the rebuild this amplifier sounds absolutely fantastic. Deep bass, the characteristic Marantz Tube-Like sound, and a stellar high end. The preamp, phono preamp and amplifier boards were all Recapped and given numerous upgrades, including better transistors, new diodes, a few 1% tolerance metal film resistors and much much more. This unit was restored to last and most importantly upgraded to sound fantastic. To summarize what is said in the long detailed section, this unit has been restored to better than new condition electronically and works absolutely beautifully. All failure prone parts have been upgraded and many parts have been upgraded to improve the audio quality. This unit should be ready for it's next 40 years of service!Please see pictures for condition, the faceplate is excellent, the knobs show typical signs of use (minor scracthing and discoloration) and there are a few scratches on the Acrylic, but overall this is a stellar sounding and looking unit.I was able to get around 90WPC out of this unit before clipping. These are absolutely fantastic amplifiers that punch well above their weight, you will not be disappointed!The bulbs were replaced with warm white LEDs, the tuner needle was left original as incandescent bulbs look the best in that position. All controls were cleaned with deoxit as well.
Please see below for the more detailed rebuild information:Power Supply:The Two main filter Capacitors were upgraded to 12, 000uf 80V High Quality Panasonic Capacitors, and given 4.7UF WIMA bypass Capacitors to help with filtering.The S1B-01-02 diodes (H801, H802 and H811-H813) were upgraded to UF4004 ultrafast soft recovery types. The C801 capacitor is the main filter for the regulated supplies and the original 470µF/63V capacitor was replaced with a 1000µF/100v long life, low ESR type. Similarly, the 330µF/50V capacitors C802 and C804 which filter the 13.5V and 35.7V supplies, respectively, were replaced with 470uf/100V low ESR types. Capacitor C803 (470µF/16V) which shunts the 14V zener, was replaced with a 470µF/50V low ESR type. The 3.3µF/35V capacitor (C805) on the base of the H806 regulator was replaced with a 10µF/50V low ESR type. Capacitors C806, C807 and C810 are used in the protection relay circuit and were also replaced with low ESR types: 22µF/50V, 330µF/35V and 47µF/25V, respectively. The protection relay (L801) was cleaned and verified to be up to original spec. The large 150 ohm/5W dropping resistor, R801, that feeds C802, was replaced with a physically smaller 150 ohm/7W vitreous enameled type, it was also raised off the board to assist in cooling.The DC output was adjusted to 35v as per the service manual and the 14v rail was checked for accuracy.Preamplifier:The 0.22µF polyester film capacitors in the high-pass input filter of the preamplifier, C401 and C402, were upgraded to 0.33µF polypropylene films; the larger capacitance value lowers the F3 to ~5Hz (minimizes phase shift in midrange of the passband). The polarized electrolytic capacitors in the signal path at C403/C404 and C407/C408 and C410/C411 and C414/C415 were repalced with polyester stacked film types of the same capacity as the originals.The DC filtering capacitor for the P400 board (C409), was originally rated at 100µF/35V and the replacement was a 220µF/50V low ESR type. Similarly, the filtering capacitors, C405 and C406, that were originally 10µF/35V were replaced with 47µF/50V low ESR types.Because the tone controls are always in circuit, and the original caps are known to be mediocre the tone board was upgraded. The polyester capacitors at C451-C456 and C457/C458 were upgraded to polypropylene types (WIMA) of the same capacity as the originals. The signal path ceramic capacitors at C457/C458, and C461/C462 were upgraded to C0G types of the same capacity as the originals. Phono Preamplifier:The stock capacitors in the input high-pass filter (C701, C702) were 0.47µF polyester film capacitors and these were upgraded with 1.0µF polypropylene film types. The polarized electrolytic capacitors C703/C704, which determine the low end roll-off of the RIAA equalization, were originally 22µF/6.3V tantalum types. Their replacements were bipolar 47µF/35V Nichicon ES capacitors; the larger capacitance lowers the F3 to ~5Hz (minimizes phase shift in midrange of the passband). The stock local filtering/decoupling capacitor, C713, was a 100µF/50V was replaced with a 220µF/50V low ESR type. The original polyester film capacitors at the output, C714/C715, were upgraded to 1µF polypropylene film types. This unit used failure prone 2SC1000 transistors for H701 - H704, these were replaced with low noise KSC1815s. The failure-prone 2SC458 transistors (H705, H706) were replaced with KSC1845 transistors. The 1S-2473 epoxy diodes (H707, H708) were replaced with 1N4148 diodes and the failure-prone VD1212 dual diode (H709) was replaced with a pair of 1N4148 diodes in series.Power Amplifier:The right channel in this unit originally arrived with blown Output Transistors in the right channel, these were replaced with the original Motorola Part to ensure consistency between both channels. The stock capacitor in the input high-pass filter (C751) was a 1.0µF polyester film type and it was upgraded to a CDE Orange drop polyester film type. The 15V zener diodes H762 and H763 were upgraded to low noise 2% variants and the capacitors C759 and C760 that shunt the zeners, were originally rated at 10µF/16V and were replaced with 47µF low ESR types, in this case I used Nichicon MUSE. The C761 capacitor, which determines the negative feedback low end cut-off, was originally a tantalum type and was replaced with a bipolar 33µF/25V Nichicon ES capacitor. The feedback resistors R757 and R759 were upgraded to 1% metal film types. UF4004 diodes were added as well as flyback diodes to protect the output devices from the surge voltage caused by turning the amp on and off. The Differential pair was replaced with Matched KSA992 transistors, this allows for a near Zero DC offset and better thermal tracking. DC offset was dialed in at 0v +-1mv and bias was set as reccommended.FM Tuner:
The FM IF board was given all new Capacitors. The 10UF caps were upgraded to Nichicon UKT capacitors of the same value. The 4.7UF caps were replaced with WIMA films of the same value. The FM Muting board was given the same treatment. The detector board, in charge of the Tuning Needle and Signal Strength was given brand new capacitors as well, of the same values as the original. UKT and UPW capacitors were used here, as well as a 1UF WIMA to replace the axial Electrolytic capacitor.The AM tuner was left original as it functions perfectly fine as is. I also left the FM MPX board due to its difficult to service location, and the fact that it functions fine as is. Stereo separation is okay on FM, some of the lower frequencies did seem to bleed over in testing, but vocals were clearly in stereo during testing, this may have been my test equipment rather than the tuner itself however. The signal strength meter on this unit is fairly sensitive, I actually noticed it fluctuating a bit with the low frequency on the FM due to the way the FM signal shifts with increased loudness/low end. FM Muting works beautifully on this model.Thanks for looking! I guarantee that this unit will not arrive DOA. Due to the nature of vintage electronics I cannot cover anything that hasn't been serviced.Thanks for reading!This item will be packed as well as possible. I always make sure that when I pack something it's done right, I package everything as if it is going to be thrown out of a moving truck at 45+MPH.
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Welcome!This listing is for a Marantz 2270 that has been near completely refurbished, rebuilt and recapped. Every board in the main audio circuit was worked on. The only boards not given a recap were t...he FM MPX board and the AM Tuner as the MPX board is fairly sensitive to changes and the AM Tuner works perfectly fine as is. This was upgraded and serviced as if I would be the one using it, however I have enough receivers already so this one gets to go to a new home.After the rebuild this amplifier sounds absolutely fantastic. Deep bass, the characteristic Marantz Tube-Like sound, and a stellar high end. The preamp, phono preamp and amplifier boards were all Recapped and given numerous upgrades, including better transistors, new diodes, a few 1% tolerance metal film resistors and much much more. This unit was restored to last and most importantly upgraded to sound fantastic. To summarize what is said in the long detailed section, this unit has been restored to better than new condition electronically and works absolutely beautifully. All failure prone parts have been upgraded and many parts have been upgraded to improve the audio quality. This unit should be ready for it's next 40 years of service!Please see pictures for condition, the faceplate is excellent, the knobs show typical signs of use (minor scracthing and discoloration) and there are a few scratches on the Acrylic, but overall this is a stellar sounding and looking unit.I was able to get around 90WPC out of this unit before clipping. These are absolutely fantastic amplifiers that punch well above their weight, you will not be disappointed!The bulbs were replaced with warm white LEDs, the tuner needle was left original as incandescent bulbs look the best in that position. All controls were cleaned with deoxit as well.
Please see below for the more detailed rebuild information:Power Supply:The Two main filter Capacitors were upgraded to 12, 000uf 80V High Quality Panasonic Capacitors, and given 4.7UF WIMA bypass Capacitors to help with filtering.The S1B-01-02 diodes (H801, H802 and H811-H813) were upgraded to UF4004 ultrafast soft recovery types. The C801 capacitor is the main filter for the regulated supplies and the original 470µF/63V capacitor was replaced with a 1000µF/100v long life, low ESR type. Similarly, the 330µF/50V capacitors C802 and C804 which filter the 13.5V and 35.7V supplies, respectively, were replaced with 470uf/100V low ESR types. Capacitor C803 (470µF/16V) which shunts the 14V zener, was replaced with a 470µF/50V low ESR type. The 3.3µF/35V capacitor (C805) on the base of the H806 regulator was replaced with a 10µF/50V low ESR type. Capacitors C806, C807 and C810 are used in the protection relay circuit and were also replaced with low ESR types: 22µF/50V, 330µF/35V and 47µF/25V, respectively. The protection relay (L801) was cleaned and verified to be up to original spec. The large 150 ohm/5W dropping resistor, R801, that feeds C802, was replaced with a physically smaller 150 ohm/7W vitreous enameled type, it was also raised off the board to assist in cooling.The DC output was adjusted to 35v as per the service manual and the 14v rail was checked for accuracy.Preamplifier:The 0.22µF polyester film capacitors in the high-pass input filter of the preamplifier, C401 and C402, were upgraded to 0.33µF polypropylene films; the larger capacitance value lowers the F3 to ~5Hz (minimizes phase shift in midrange of the passband). The polarized electrolytic capacitors in the signal path at C403/C404 and C407/C408 and C410/C411 and C414/C415 were repalced with polyester stacked film types of the same capacity as the originals.The DC filtering capacitor for the P400 board (C409), was originally rated at 100µF/35V and the replacement was a 220µF/50V low ESR type. Similarly, the filtering capacitors, C405 and C406, that were originally 10µF/35V were replaced with 47µF/50V low ESR types.Because the tone controls are always in circuit, and the original caps are known to be mediocre the tone board was upgraded. The polyester capacitors at C451-C456 and C457/C458 were upgraded to polypropylene types (WIMA) of the same capacity as the originals. The signal path ceramic capacitors at C457/C458, and C461/C462 were upgraded to C0G types of the same capacity as the originals. Phono Preamplifier:The stock capacitors in the input high-pass filter (C701, C702) were 0.47µF polyester film capacitors and these were upgraded with 1.0µF polypropylene film types. The polarized electrolytic capacitors C703/C704, which determine the low end roll-off of the RIAA equalization, were originally 22µF/6.3V tantalum types. Their replacements were bipolar 47µF/35V Nichicon ES capacitors; the larger capacitance lowers the F3 to ~5Hz (minimizes phase shift in midrange of the passband). The stock local filtering/decoupling capacitor, C713, was a 100µF/50V was replaced with a 220µF/50V low ESR type. The original polyester film capacitors at the output, C714/C715, were upgraded to 1µF polypropylene film types. This unit used failure prone 2SC1000 transistors for H701 - H704, these were replaced with low noise KSC1815s. The failure-prone 2SC458 transistors (H705, H706) were replaced with KSC1845 transistors. The 1S-2473 epoxy diodes (H707, H708) were replaced with 1N4148 diodes and the failure-prone VD1212 dual diode (H709) was replaced with a pair of 1N4148 diodes in series.Power Amplifier:The right channel in this unit originally arrived with blown Output Transistors in the right channel, these were replaced with the original Motorola Part to ensure consistency between both channels. The stock capacitor in the input high-pass filter (C751) was a 1.0µF polyester film type and it was upgraded to a CDE Orange drop polyester film type. The 15V zener diodes H762 and H763 were upgraded to low noise 2% variants and the capacitors C759 and C760 that shunt the zeners, were originally rated at 10µF/16V and were replaced with 47µF low ESR types, in this case I used Nichicon MUSE. The C761 capacitor, which determines the negative feedback low end cut-off, was originally a tantalum type and was replaced with a bipolar 33µF/25V Nichicon ES capacitor. The feedback resistors R757 and R759 were upgraded to 1% metal film types. UF4004 diodes were added as well as flyback diodes to protect the output devices from the surge voltage caused by turning the amp on and off. The Differential pair was replaced with Matched KSA992 transistors, this allows for a near Zero DC offset and better thermal tracking. DC offset was dialed in at 0v +-1mv and bias was set as reccommended.FM Tuner:
The FM IF board was given all new Capacitors. The 10UF caps were upgraded to Nichicon UKT capacitors of the same value. The 4.7UF caps were replaced with WIMA films of the same value. The FM Muting board was given the same treatment. The detector board, in charge of the Tuning Needle and Signal Strength was given brand new capacitors as well, of the same values as the original. UKT and UPW capacitors were used here, as well as a 1UF WIMA to replace the axial Electrolytic capacitor.The AM tuner was left original as it functions perfectly fine as is. I also left the FM MPX board due to its difficult to service location, and the fact that it functions fine as is. Stereo separation is okay on FM, some of the lower frequencies did seem to bleed over in testing, but vocals were clearly in stereo during testing, this may have been my test equipment rather than the tuner itself however. The signal strength meter on this unit is fairly sensitive, I actually noticed it fluctuating a bit with the low frequency on the FM due to the way the FM signal shifts with increased loudness/low end. FM Muting works beautifully on this model.Thanks for looking! I guarantee that this unit will not arrive DOA. Due to the nature of vintage electronics I cannot cover anything that hasn't been serviced.Thanks for reading!This item will be packed as well as possible. I always make sure that when I pack something it's done right, I package everything as if it is going to be thrown out of a moving truck at 45+MPH.
