Marantz 250M Vintage Stereo Power Amplifier Refurbished/Rebuilt/Restored/Recap
Item History & Price
| Reference Number: Avaluer:6809692 | Brand: Marantz |
| Type: Power Amplifier | Model: 250M |
| MPN: Does Not Apply |
Welcome! This listing is for one of Marantz's greatest amplifiers, the 250M. This unit has been gone through and completely restored back to better than factory condition internally.
Reasonable offers are always considered and appreciated!This unit was known, back in the day, to be rather troublesome, due to some oversights in the original transistor choices. Marantz later released several different service bullitens to update and address the issues these amps had early on. The two... biggest upgrades were the addition of flyback diodes to keep the amp from destroying itself during power off, and changing the driver and predriver transistors, if necessary.This unit has been completely recapped, using high quality Vishay caps in the amps, as well as some Nichicon Muse and UPW caps where applicable. The relay board was recapped as well. This unit was restored with sound quality and longevity in mind.The 1UF high pass filter for the audio input was upgraded to a 1UF Cornell Dublier Orange Drop Capacitor, which is fairly highly regarded amongst tube amplifer enthusiasts. The main filter capacitors were upgraded to 100V 24, 000 UF Nippon Chemi-Con capacitors which fit perfectly in place of the old capacitors. I also added some 3.3UF WIMA bypass capacitors to help with power filtering. Both amplifer boards were updated to have flyback diodes for protection as per the service bullitens. The Driver transistors are the more robust SJ2585 units, which ensure that this amplifer will function reliably. The predriver transistors were pulled and tested but kept with what the amp arrived to me with. The differential input pair of transistors, which regulate bias, were pulled, tested, given a thermal compound treatment and bonded together with heat shrink to ensure accurate thermal tracking. All power and output stage transistors got new thermal paste as well. The DC offset and bias were adjusted back to spec to ensure cool operation. Given all of the servicing this amplifer should easily last another 40 years!I have also cleaned all the contacts, cleaned off the faceplate, and cleaned the knobs for meter sensitivity.Ive been pushing this amplifer extremely hard for the past few days, post servicing, and it sounds absolutely fantastic and works perfectly as one should expect a fully serviced/redurbished marantz amplifer to sound. The lights were upgraded to warm white LEDs for a cooler operation, however if the buyer wishes i can swap them back to incandescent bulbs.I service and test all of my amplifiers personally. I have rebuilt many marantz amplifiers and have always found a restored unit to sound significantly better than an unrestored one. I use a restored 250M in my personal HiFi and have always been blown away by how great an amplifer it is.This unit appears to have been in commercial use in the past as someone has added a set of TRS outputs for speakers next to the original screw terminals. This of more benefit as the screw terminals can be fairly annoying to deal with.This units specifications are as follows:Power output: 126 watts per channel into 8Ω (stereo)Frequency response: 2Hz to 100kHzTotal harmonic distortion: 0.1%Damping factor: 100Input sensitivity: 1.5VSignal to noise ratio: 106dBGet your hands on one of the best performing, and best looking vintage power Amplifiers!Please see pictures for condition, this unit is very clean overall, probably worthy of an A- rating, it has a number engraved on the bottom of the faceplate, but aside from that the front of the unit is immaculate. There is also some wear on the metal ln top of the amplifer.I have also included pictures of each circuit board serviced to ensure you know what you are getting.Personally, i would never want to use one of these units unrestored as if its an early model there is a good chance that it will blow its transistors.Amplifer is very heavy, I will do my absolute best to ensure that it ships safely! Buy with confidence! This item has its handling time set to 3 days in order to ensure i have adequate time to properly package the unit. Thanks!!!!I have been using this amplifer since i serviced it and it sounds absolutely amazing, one of the best vintage amplifiers out there!See my other listing for a model 3600 preamp that pairs well with this
Reasonable offers are always considered and appreciated!This unit was known, back in the day, to be rather troublesome, due to some oversights in the original transistor choices. Marantz later released several different service bullitens to update and address the issues these amps had early on. The two... biggest upgrades were the addition of flyback diodes to keep the amp from destroying itself during power off, and changing the driver and predriver transistors, if necessary.This unit has been completely recapped, using high quality Vishay caps in the amps, as well as some Nichicon Muse and UPW caps where applicable. The relay board was recapped as well. This unit was restored with sound quality and longevity in mind.The 1UF high pass filter for the audio input was upgraded to a 1UF Cornell Dublier Orange Drop Capacitor, which is fairly highly regarded amongst tube amplifer enthusiasts. The main filter capacitors were upgraded to 100V 24, 000 UF Nippon Chemi-Con capacitors which fit perfectly in place of the old capacitors. I also added some 3.3UF WIMA bypass capacitors to help with power filtering. Both amplifer boards were updated to have flyback diodes for protection as per the service bullitens. The Driver transistors are the more robust SJ2585 units, which ensure that this amplifer will function reliably. The predriver transistors were pulled and tested but kept with what the amp arrived to me with. The differential input pair of transistors, which regulate bias, were pulled, tested, given a thermal compound treatment and bonded together with heat shrink to ensure accurate thermal tracking. All power and output stage transistors got new thermal paste as well. The DC offset and bias were adjusted back to spec to ensure cool operation. Given all of the servicing this amplifer should easily last another 40 years!I have also cleaned all the contacts, cleaned off the faceplate, and cleaned the knobs for meter sensitivity.Ive been pushing this amplifer extremely hard for the past few days, post servicing, and it sounds absolutely fantastic and works perfectly as one should expect a fully serviced/redurbished marantz amplifer to sound. The lights were upgraded to warm white LEDs for a cooler operation, however if the buyer wishes i can swap them back to incandescent bulbs.I service and test all of my amplifiers personally. I have rebuilt many marantz amplifiers and have always found a restored unit to sound significantly better than an unrestored one. I use a restored 250M in my personal HiFi and have always been blown away by how great an amplifer it is.This unit appears to have been in commercial use in the past as someone has added a set of TRS outputs for speakers next to the original screw terminals. This of more benefit as the screw terminals can be fairly annoying to deal with.This units specifications are as follows:Power output: 126 watts per channel into 8Ω (stereo)Frequency response: 2Hz to 100kHzTotal harmonic distortion: 0.1%Damping factor: 100Input sensitivity: 1.5VSignal to noise ratio: 106dBGet your hands on one of the best performing, and best looking vintage power Amplifiers!Please see pictures for condition, this unit is very clean overall, probably worthy of an A- rating, it has a number engraved on the bottom of the faceplate, but aside from that the front of the unit is immaculate. There is also some wear on the metal ln top of the amplifer.I have also included pictures of each circuit board serviced to ensure you know what you are getting.Personally, i would never want to use one of these units unrestored as if its an early model there is a good chance that it will blow its transistors.Amplifer is very heavy, I will do my absolute best to ensure that it ships safely! Buy with confidence! This item has its handling time set to 3 days in order to ensure i have adequate time to properly package the unit. Thanks!!!!I have been using this amplifer since i serviced it and it sounds absolutely amazing, one of the best vintage amplifiers out there!See my other listing for a model 3600 preamp that pairs well with this
