Sony TC-280 Tape Recorder.
Circuit Diagram - note pre-amps only.
I purchased this machine as a present for my dad around 1973/74ish. It has a very good specification and I thought it would take over from the Ferrograph Series 4; I was wrong, he carried on using the Ferrograph and the new Sony saw very little use.
GENERAL THOUGHTS ABOUT SONY.
We used to sell a lot of Sony and they made excellent products. Their philosophy at that time was to make things independently of other makers so that they wouldn't get caught up in having to pay licence fees to others. Everyone else paid a fee to RCA (I think) in the USA to be able to use shadow-mask type colour TV cathode ray tubes (CRTs) - not Sony; they developed the excellent Trinitron tube to avoid paying the fee. Another example was the decoder for the PAL colour TV transmissions, everyone else paid their dues to Telefunken - not Sony; they developed their own. I seem to recall with the first 13" sets - KV1300? - that only alternate lines of colour information were decoded; half the picture was in black & white - but you couldn't tell on such a small screen.
HOWEVER.
It must have been the 2nd half of the 1970s when they introduced the KV1810UB. These sets had Gate Control Switches (GCSs) in them that were supposed to combine the advantages of a transistor and a thyristor, my memory is that only Sony used these unreliable devices in domestic CTVs. Just out of guarantee the GCSs would fail and they were very expensive to fix; I think around £50 (that's £50 in 1978 money!). Customers were most unhappy, especially when they failed again say six months later. Customers were blaming us rather than Sony, even though Sony could not come up with a reliable answer. We had no choice - we had to stop dealing with Sony to protect our reputation. In the end we did make the sets reliable by removing the GCSs and fitting conventional transistors in their place run by drive circuitry taken out of scrap Murphy and Bush CTVs. The Health & Safety police would be on to you like a ton of bricks if you did it today.
So you can probably tell I've not been too much of a Sony fan for the last 30 or so years!!!! To be fair:
A) When their different technology worked it worked well.
B) I think their philosophy is different today and they have worked with other manufactures; Compact Discs for instance I think are a collaboration between Philips & Sony.