My son inherited a Fisher Model 173 and loves its sound. It is a nice sounding amp from 1973 with a warm tube-like character and works well with his vinyl and FM playback.
It's sounding a little soft and is lacking a bit of detail and punch. I found a guy, Todd of Timerider.net, who performs full restorations of vintage gear, but he broke a finger and can no longer do the work. I'm looking for someone who would be willing to do the restoration. I have the schematic and service manual.
He offered to perform the following work:
• Fully disassembled and clean. Inputs/outputs cleaned.
• All switches cleaned (pulled, if possible) and lubricated internally.
• All capacitors on all boards replaced, including main filter capacitors (Audio-quality and/or stacked film capacitors in tuner, pre-amp, amplifier, protection, power and tone stages (WIMA, Kemet, Nichicon and/or Panasonic capacitors).
• All Zener and Schottky diodes replaced.
• All trouble-prone or hot-running transistors replaced with modern, low noise units.
• Output transistors pulled, cleaned and re-set with new thermal pads and thermal grease.
• Heavy-duty regulator transistors on power supply board.
• New power regulator resistors on power supply board.
• New rectifier diodes x4 on power supply board.
• Adjust amp circuit with new Bourns trim-pots.
• Adjusted Bias to factory spec.
• New lamps.
• New snubber circuit on power switch.
• Circuit boards inspected for any cracking, burning, etc. Any cracked solder joints re-flowed, especially in high-heat areas.
• Bench tested for 12 hours under an 8 ohm load.
It's sounding a little soft and is lacking a bit of detail and punch. I found a guy, Todd of Timerider.net, who performs full restorations of vintage gear, but he broke a finger and can no longer do the work. I'm looking for someone who would be willing to do the restoration. I have the schematic and service manual.
He offered to perform the following work:
• Fully disassembled and clean. Inputs/outputs cleaned.
• All switches cleaned (pulled, if possible) and lubricated internally.
• All capacitors on all boards replaced, including main filter capacitors (Audio-quality and/or stacked film capacitors in tuner, pre-amp, amplifier, protection, power and tone stages (WIMA, Kemet, Nichicon and/or Panasonic capacitors).
• All Zener and Schottky diodes replaced.
• All trouble-prone or hot-running transistors replaced with modern, low noise units.
• Output transistors pulled, cleaned and re-set with new thermal pads and thermal grease.
• Heavy-duty regulator transistors on power supply board.
• New power regulator resistors on power supply board.
• New rectifier diodes x4 on power supply board.
• Adjust amp circuit with new Bourns trim-pots.
• Adjusted Bias to factory spec.
• New lamps.
• New snubber circuit on power switch.
• Circuit boards inspected for any cracking, burning, etc. Any cracked solder joints re-flowed, especially in high-heat areas.
• Bench tested for 12 hours under an 8 ohm load.
rama, You may be right about its signature sound, but it's hard to believe the original caps especially, along with the other 50+ year old parts aren't
degrading the sound to a noticeable degree.
Todd's quote for the work was $285, which would be well worth it to me. The restoration was supposed to be my xmas gift to him.
degrading the sound to a noticeable degree.
Todd's quote for the work was $285, which would be well worth it to me. The restoration was supposed to be my xmas gift to him.
I have several HK receivers (made in the 70s), and they all work well with no servicing whatsoever.
Preventative maintenance is not necessarily a good idea for "vintage" audio equipment.
That quote may look cheap when you try to find someone else to do the same amount of work.
Most tech labor is $100/hour these days, plus parts. And the parts they use will be cheap, low grade parts.
Preventative maintenance is not necessarily a good idea for "vintage" audio equipment.
That quote may look cheap when you try to find someone else to do the same amount of work.
Most tech labor is $100/hour these days, plus parts. And the parts they use will be cheap, low grade parts.
Fisher equipment was very well made. I would agree with Ray except I would have it checked. Get required work done, don't rebuilt the entire thing.
I would probably replace coupling caps and out of tolerance resistors (probably more than a couple). I would check the filter capacitors at the very least.
That estimate was very low.
I would probably replace coupling caps and out of tolerance resistors (probably more than a couple). I would check the filter capacitors at the very least.
That estimate was very low.