What were the earliest solid state Altec amplifiers?

[Sanfansui]

What were the very earliest solid state amplifiers made by Altec?
And what years were they first made?

 

[Pio1980]

Theatre or home audio?

 

[Sanfansui]

Theatre or home audio?

I'm curious about both!

 

[Buck Rogers]

Altec 1593 and 1594 are some of the first solid state commercial amplifiers.

1569 and 1570b were some of the last tube amps they made.

 

[bowtie427ss]

Probably the 351A circa 1960/61.

1569 and 1570b were some of the last tube amps they made.

Made well into the 70's, and concurrently with 1593 and 1594.

 

[Sanfansui]

What are the differences between the 1593A and 1593B?

I found https://greatplainsaudio.com/wp-content/uploads/2016/06/1593B.1.pdf
but what does "operates from negative ground source" mean? Is this different than how the 1593A works?

 

[bowtie427ss]

What are the differences between the 1593A and 1593B?

1593A has a fuse on the amplifier(DC) side of the power supply that's deleted for the 1593B, beyond that i don't see any significant differences.

 

[Pio1980]

The early solid state were good journeyman low maintainance amps, but afaik not particularly sought like the tube units they supplanted.

 

[Sanfansui]

The 1593B is listed as having 61db of gain, but when I calculate its gain using the input sensitivity of .8 Volts and power output of 50W (at 8 ohms), I get about 28 db of gain. Where did I go wrong?

https://greatplainsaudio.com/wp-content/uploads/2016/06/1593B.1.pdf

 

[Dswankey]

What were the very earliest solid state amplifiers made by Altec?
And what years were they first made?

While AK is a great resource of information a simple search on Google came up with this, tons of info here for your curiosity

ALTEC LANSING HISTORY

INTRODUCTION