Beyond the list of standard restoration steps detailed on the main page, here are some added notes for this unit :

I bought this remarkable set of Sony’s top-of-the-line separates from the original owner who purchased them at the Air Force PX in 1972.  I jumped at these as the matching wood cabinets are so rarely seen and everything was in excellent condition.  They each came with original owner and service manuals with the hand-written test results that the Sony technicians recorded before shipping the TA2000F and TA3200F.  They were clearly very well treated being super clean inside and out.

Sony pulled out all the stops in designing and building these units to compete with the best separates other high-end vendors had to offer in the early 1970s.  Each of these is highly regarded to this day, and these excellent examples have been playing together for over 50 years (!)

ST5000F

Initial checks showed rather high resistance across the power switch (likely due to dirty/corroded contacts).  Thankfully, Sony used an industry-standard 15A micro-switch, so I was able to buy/install a brand new replacement while doing the recap.  Given this issue, I decided to also replace the 15A micro-switches in the similar TA2000F and TA3200F power switch assemblies.

Initial powered testing went well, but the tuning meter was not moving.  This turned out to be a bad meter and (as I feared) no one was selling exact replacements. 

I decided to purchase another ST5000F as a parts unit which I got fairly “cheap” (vs others on eBay) as it was a “Japanese market” unit (100VAC) plus the FM tuning range is lower (only 76 to 90 MHz vs US range of 88 to 108 MHz).  The tuning meter is exactly the same, so problem solved.  I will likely sell the parts unit to someone who parts-out stereo gear (to recoup some of my expense plus support the next guy looking for ST5000F parts).

While I knew what I was getting with a tuner meant for the Japanese market, I suspect many may get burned when buying vintage Sony gear from sellers in Tokyo and then can’t use them in the US (buyer, beware!)

This tuner is “FM-only” and needed little tweaking during alignment.  The only issue I saw was something common to many older FM tuners from Kenwood, Pioneer, etc.  The FM Stereo lamp comes on too often as the circuit also incorrectly activates on noise between stations.  That said, it really performs well and sounds great.

TA2000F

This preamp has many high-end design features such as dedicated eq amp stages for every low level input (phono1, phono2 and mic).  Phono1 has a “low” level mode that should work with most MC cartridges (down to 0.06mV) plus a “high” mode for MM (down to 1.2mV) with multiple impedance choices for each mode.  Phono2 is always in “high” mode.  It also has 110mv min inputs for Tuner, Aux1, Aux2, Aux3, Tape in 1 and Tape in 2 (total of 6 inputs for things like CD players, etc).

It has a unusually high internal supply (150V DC !) which, combined with an all-FET topology minimizes noise in the phono1 and phono2 eq amps.  This required using some special high voltage caps as I did the recap.  The “flat amp” stage (No RIAA decompression like the phono eq amps) also are all-FET, but only need 35V DC given the higher signal levels at the inputs.  

The power switch was replaced (as described for the ST5000F) and initial powered testing went fine.  After the ST5000F experience, I was relieved to see both VU meters operating correctly.

I always spend many hours listening to what I am working on.  The payoff is catching intermittent issues that don’t happen in only 10 minutes.  In this case, there were occasional “pops” on the left channel after 2 or 3 hours.  This is a classic “noisy transistor” issue which I traced to the flat amplifier board.  I replaced all the FETs in the flat amplifier and the issue was resolved.  I was careful to use modern equivalents recommended on AudioKarma and measure/match IDSS ranges of the new devices to match original FET specs.

TA3200F

This is a “no nonsense”, well built power amp with an enormous transformer filling much of the interior.  Beyond the TA2000F preamp volume/balance controls, there are also left and right channel volume knobs on the TA3200F to enable more adjustments.  It also has 3 power level settings (25W, 50W and 100W per channel).  Then there is the impressive damping factor of 170 (8 ohms, 1KHz).  

Given the quality of this amplifier, I decided to upgrade the speaker terminals to modern “5-ways” as part of the recap process.  Since the main caps are mounted “screws up”, I was able to modestly up-cap using Kemet’s excellent PEH series capacitors (~8500uF each vs the 8000uF originals).  The power switch was also replaced.