I bought a pair of speakers from a fellow on BT and he threw in a 'partly working' 700T as a gift. I had not had any experience with early Fisher solid state gear, so was quite interested to pop the covers and see what it was all about, particularly the sound after restoring. This one was dusty and had been dropped on the upper left hand corner of the (very robust but now quite bent) front panel and had a piece of old masking tape on the back labeled "bad RT channel." I figured there would be some work and parts involved but, hey, it was free and gave me a chance to compare the late 60's initial Fisher SS gear to the tube gear I have restored.
I did some research and there's not a whole lot out there on the early Fisher solid state gear (at least compared to the classic tube amps and receivers), but I found a couple of good AK Fisher Forum threads that were very helpful and a couple of other on-line threads as well. I found a very good scan of the Service Manual, but have never been able to find an owner's manual anywhere on line (the 600T OM is available and appears close, feature-wise).
The 700T was the top of the line receiver of all Fisher types (tube and SS) in the 1968 time frame, offered alongside the 200T, 220T, 500T, 550T and tube models 400, 500C, and 800C as they phased out. The 700T is the highest power rated solid state receiver offered in this lineup at 50W RMS per channel (see attached description and specs from the 1968 Fisher catalogue--interesting comparison with the tube receivers). The 220T and 550T were noteworthy for having 'microcircuit' components (IC's).
The 700T was priced at a level that would be thousands of today's dollars and is a very well built piece of gear. All the transistors are silicon, including the drivers and outputs and the design appears quite robust. The tuner is a "Super Synchrode" FET type.
Initial examination showed:
-Socketed transistors! Most transistors in the unit are mounted in their own socket (except for the outputs).
-Roomy and pretty robust-looking PC boards for the main circuits, as well as some free-mounted transistors mounted to tie strips on the chassis.
-LOTS of small electrolytic capacitors in the signal path and otherwise, including quite a few 1 uF, 0.5 uF, and 4 uF (more on these later!).
Initial power-up revealed several problems, particularly:
-No shorted power supply caps (dim bulb tester stayed dim when bringing it up on the Variac). Fuses all intact (including the output channel fuses)
-Very weak audio output on the left (not the right!) channel
-Stereo beacon light not working on even strong, stereo stations
-No FM stereo output in FM stereo mode--all mono all the time
-No audio in "FM Stereo" mode, but audio in "FM Auto" and "FM Mono" modes.
-The usual scratchy pots and switches to deal with.
All of this was dealt with over a few hours work on the bench, and I'll describe what I found and how I resolved it in subsequent posts just for the record.
I neglected to take 'before' pictures, but a couple of cleaned-up 'after' shorts are shown below. More to come!
Dave
From the 1968 Fisher Catalog:
View attachment 1336432
My 700T in the 'after' state after some the restore (including straightening the bend front panel corner):
View attachment 1336444
I did some research and there's not a whole lot out there on the early Fisher solid state gear (at least compared to the classic tube amps and receivers), but I found a couple of good AK Fisher Forum threads that were very helpful and a couple of other on-line threads as well. I found a very good scan of the Service Manual, but have never been able to find an owner's manual anywhere on line (the 600T OM is available and appears close, feature-wise).
The 700T was the top of the line receiver of all Fisher types (tube and SS) in the 1968 time frame, offered alongside the 200T, 220T, 500T, 550T and tube models 400, 500C, and 800C as they phased out. The 700T is the highest power rated solid state receiver offered in this lineup at 50W RMS per channel (see attached description and specs from the 1968 Fisher catalogue--interesting comparison with the tube receivers). The 220T and 550T were noteworthy for having 'microcircuit' components (IC's).
The 700T was priced at a level that would be thousands of today's dollars and is a very well built piece of gear. All the transistors are silicon, including the drivers and outputs and the design appears quite robust. The tuner is a "Super Synchrode" FET type.
Initial examination showed:
-Socketed transistors! Most transistors in the unit are mounted in their own socket (except for the outputs).
-Roomy and pretty robust-looking PC boards for the main circuits, as well as some free-mounted transistors mounted to tie strips on the chassis.
-LOTS of small electrolytic capacitors in the signal path and otherwise, including quite a few 1 uF, 0.5 uF, and 4 uF (more on these later!).
Initial power-up revealed several problems, particularly:
-No shorted power supply caps (dim bulb tester stayed dim when bringing it up on the Variac). Fuses all intact (including the output channel fuses)
-Very weak audio output on the left (not the right!) channel
-Stereo beacon light not working on even strong, stereo stations
-No FM stereo output in FM stereo mode--all mono all the time
-No audio in "FM Stereo" mode, but audio in "FM Auto" and "FM Mono" modes.
-The usual scratchy pots and switches to deal with.
All of this was dealt with over a few hours work on the bench, and I'll describe what I found and how I resolved it in subsequent posts just for the record.
I neglected to take 'before' pictures, but a couple of cleaned-up 'after' shorts are shown below. More to come!
Dave
From the 1968 Fisher Catalog:
View attachment 1336432
My 700T in the 'after' state after some the restore (including straightening the bend front panel corner):
View attachment 1336444
Last edited: