http://www.thevintageknob.org/marantz-PM-94.html
Without getting into too much detail I have among others, a Marantz pm 94 which was one of Marantz's flagship stereo amplifiers in the early 90's. At some stage years back I popped one of the output channels.With exuberance I set off finding the correct replacement parts from all over the world. Repair done, stupid me decided that the one side of the amp ran a little bit warmer (x 2 mono circuits) and set about fiddling with the bias current. BOOM :walled: In a couple of seconds I managed to destroy this thing of beauty. After numerous attempts of self fixing (known today as further damaging)
I chucked it in storage.
Fast forward to the present. After suffering years of seperation anxiety, I decided it was time to restore this classic. After phoning around I was referred to a well known repairer in CT . Imagine my suprise at this gentleman's outright arrogance, demanding a 5 K upfront payment just to look at it!!! Quickly told him in no uncertain terms to shove it where the Sun don't shine :nutter:
Enter RICK THE AMP MAN :thumbs:. What a pleasant Gentleman to work with. He set about repairing and restoring the Marantz. No stone was left unturned in his quest to restore this amplifier to it's former glory. This included tracing all my botched repair attemps, as well as re-soldering all dry solder joints etc and replacing all the new upgraded components. Anybody with knowledge of this amplifier, will attest to the complexity and difficult layout of this design.
It dawned on me very early in this restore project that If Rick had to charge me labour as per hours spent,this amplifier would never see the light of day. Instead I found a man, absolutely passionate about his work, and for all things Audio!
Back to the Marantz. Original specs were 140 watt into 8 oms with the first quarter in Class A. This was typically 28 -32 watts Class A as tested in numerous reviews. I have always found this Amp to be absolutely musical, with goosebump enspiring vocal and instrument reproduction Someone once described it as the closest Tube sounding Transistor amp he had ever heard. However I always found it lacking in the slam department with not enough dynamics and control in the bass department.
Imaging my suprise when I listened to her again. With the latest spec Toshiba mosfets and completely repopulated and upgraded comparrator board (the bias control and switching circuit) all that i found lacking is now corrected. We now have just over 50 watt into 8 ohms Class A and then she switches to class A/B for just over 200 watts per channel.
This amp now sounds absolutely out of this world!!
Well done and thank you again to Rick and all his dedicated hours on this amplifier. What a job well done!!!! :thumbs: :thumbs: :thumbs:
Some trivia....The Cerafine caps on the psu alone will set you back about 10 K today. All signal path caps are Elna styrol copper film caps. The whole chassis is copper clad including the screws to keep eddie currents at bay!. They just don't make em like they used too :groovy:
Without getting into too much detail I have among others, a Marantz pm 94 which was one of Marantz's flagship stereo amplifiers in the early 90's. At some stage years back I popped one of the output channels.With exuberance I set off finding the correct replacement parts from all over the world. Repair done, stupid me decided that the one side of the amp ran a little bit warmer (x 2 mono circuits) and set about fiddling with the bias current. BOOM :walled: In a couple of seconds I managed to destroy this thing of beauty. After numerous attempts of self fixing (known today as further damaging)
I chucked it in storage.Fast forward to the present. After suffering years of seperation anxiety, I decided it was time to restore this classic. After phoning around I was referred to a well known repairer in CT . Imagine my suprise at this gentleman's outright arrogance, demanding a 5 K upfront payment just to look at it!!! Quickly told him in no uncertain terms to shove it where the Sun don't shine :nutter:
Enter RICK THE AMP MAN :thumbs:. What a pleasant Gentleman to work with. He set about repairing and restoring the Marantz. No stone was left unturned in his quest to restore this amplifier to it's former glory. This included tracing all my botched repair attemps, as well as re-soldering all dry solder joints etc and replacing all the new upgraded components. Anybody with knowledge of this amplifier, will attest to the complexity and difficult layout of this design.
It dawned on me very early in this restore project that If Rick had to charge me labour as per hours spent,this amplifier would never see the light of day. Instead I found a man, absolutely passionate about his work, and for all things Audio!
Back to the Marantz. Original specs were 140 watt into 8 oms with the first quarter in Class A. This was typically 28 -32 watts Class A as tested in numerous reviews. I have always found this Amp to be absolutely musical, with goosebump enspiring vocal and instrument reproduction Someone once described it as the closest Tube sounding Transistor amp he had ever heard. However I always found it lacking in the slam department with not enough dynamics and control in the bass department.
Imaging my suprise when I listened to her again. With the latest spec Toshiba mosfets and completely repopulated and upgraded comparrator board (the bias control and switching circuit) all that i found lacking is now corrected. We now have just over 50 watt into 8 ohms Class A and then she switches to class A/B for just over 200 watts per channel.
This amp now sounds absolutely out of this world!!
Well done and thank you again to Rick and all his dedicated hours on this amplifier. What a job well done!!!! :thumbs: :thumbs: :thumbs:
Some trivia....The Cerafine caps on the psu alone will set you back about 10 K today. All signal path caps are Elna styrol copper film caps. The whole chassis is copper clad including the screws to keep eddie currents at bay!. They just don't make em like they used too :groovy:
