LUXMAN vintage audio
Sony ST-4950 FM/AM Tuner
Around 1976 Sony company came with its ST-4950 high quality tuner on the European market.
In some respect it was a competitor to the cheaper Luxman tuners.
The Sony ST-4950 tuner incorporates special custom Sony IC - IF amps as you can see on the photo.
It has a FM 4 gang varicap on the Alps front-end. It employs 2 dual gate mos-fets in the front-end.
It has a standard Hitachi IC for stereo reception and FM demodulation is a simple standard 'ratio' diode version.
Also a LF filter block is on the pcb. No provision for Anti-Birdies.
The power supply is simple but effective. The total electronic setup is simple but effective.
It has a hi-blend switchable filter. A multipath switch is available. No bandwith switch.
AM reception is also an option.
This tuner was also issued with Dolby, this version has none but an empty space.
It is a huge sized tuner and the cabinet is 70% empty: Its made to accompany the amplifiers of Sony like the TA-4650.
User manual in PDF click here.
Service manual Sony ST-4950 in PDF click here
This above manual is in average quality, there is a version available in HQ: you can mail me for info.
Electrolytic caps can be replaced and heatsinking of the power supply transistor can be improved.
Set the deėmphasis-compensation to 75 µS in USA and 50 µS in Europe.
This tuner is very sensitive and easy to use, it lacks the more extensive control of most Luxmans.
The sound is great and reception is good.
© Hans Hilberink - PE1MMK ® 2003 - Last update: 15-01-2018.