KLH was a quality '60s company that has devolved in the last few decades to low end consumer schlock. Started by the renowned Henry Kloss, Malcolm Low, and Anton Hoffman (each contributing an initial to the name) KLH produced sonic quality with cosmetic style.
I confess I had never seen a KLH receiver in the flesh before the relatively basic 51 arrived.
This unit was clean and in working condition with a modest case of slightly damaged switches. The years tend to be unkind to exposed switches on electronics. These were repaired after this photo was taken. All the bulbs worked and the 51 is quite attractive when lit, blue on silver. Note the KLH logo on the left. Mike likens it to a sonic pressure wave. Whatever, it looks cool.
Here are the innards:
The 51 is a simple 3 board receiver with a two gang tuner section at the right. The amp/preamp board in the center (half of which is visible) had the the two large caps replaced with Sanyos after this photo was taken as a last minute precaution. They tested fine, but it seemed prudent. Not visible is the preamp section underneath the shield just in front of the output stage. The power supply board is at the left. The inputs along the back, just behind the heatsinks, are shielded. It should be noted the vinyl covered exterior case was shielded on the inside, a rare touch in this price class. KLH obviously cared about shielding.
A total of 41 capacitors were changed, mostly with Panasonic FCs.
Back in the '70s a relatively modest receiver was a sonic bargain. Despite relatively modest wattage they could drive a reasonable set of speakers to unreasonable sound levels with grace. The KLH 51 is no exception. The FM tuner sounds good. Even the AM tuner sounds good. And it looks good.