SAE "X" Series
I started out intending only to collect the "X" series gear that had the optional black face plate instead of grey, but I can't control myself. I decided to collect both grey and black.
 

SAE R-1 Rack 

    1. On top of rack - SAE R201 Prototype Receiver
    2. On top of rack - SAE X-25A Amplifier

Mounted in rack

1. SAE X-BP-1 Filler Panel

2. SAE X-1PS Preamplifier Power Supply

3. SAE X-1P Preamplifier

4. SAE X-BP-2 Filler Panel

5. SAE X-T101 Tuner

6. SAE X-10A Amplifier

7. SAE X-15A Amplifier

8. SAE X-25A Amplifier

9. SAE X-25A Amplifier

You will notice on "X" series components that you will see two different shades of grey anodizing. I don't know if this was intentional or a quality control issue, but I am trying to find out.

This is the power cord tag for the "X" series

This is my latest acquisition:  a T101 AM/FM Tuner with a silver/gray anodized face plate to match the "X" series amps and pre-amp thus making it an "X-T101". Now I have to track down the X-E101 Equalizer.
 

I have acquired two black faced X10A-s. One without the power switch and one with. I also finally found an X15A black. This is the only one I have ever seen but I am sure there are a few more out there. Now I have to locate the rest.
 

This is a picture of an X15A amplifier with an on/off switch (also on the X10A). Due to European regulations enacted in the early 1980's, preamplifiers were not allowed to have the switched outlets with the higher amperage ratings required for amplifiers and therefore audio manufactures had to re-tool any amps that did not have on/off switches in order to export them to Europe. Some of these amps can be found stateside because Pacific Stereo also requested the on/off switch on the "X" and "01"units they sold.