Apropos of nothing -- and Class D amplification

[mhardy6647]

I was looking up something else entirely (the history of the IHF specs for FM tuners ) in the wonderful resource that is www.worldradiohistory.com and I happened to notice Part 2 of an interesting two part article series in Audio magizine in 1963.

Now -- yeah -- I know Class D amplifiers have been around for a while, and -- yeah -- I know that the D doesn't stand for digital ... but, dang, 1963 was a while ago now.

Just thought it worthy of mention:
source: https://worldradiohistory.com/Archive-All-Audio/Archive-Audio/60s/Audio-1963-08.pdf

 

[DonH56]

Class D was invented in the 50's... And yes, D was just the next letter in the line of amplifier classes as they were invented and defined (A, B, C, then came D).

 

[SIY]

I was looking up something else entirely (the history of the IHF specs for FM tuners ) in the wonderful resource that is www.worldradiohistory.com and I happened to notice Part 2 of an interesting two part article series in Audio magizine in 1963.

View attachment 113779

Now -- yeah -- I know Class D amplifiers have been around for a while, and -- yeah -- I know that the D doesn't stand for digital ... but, dang, 1963 was a while ago now.

Just thought it worthy of mention:
source: https://worldradiohistory.com/Archive-All-Audio/Archive-Audio/60s/Audio-1963-08.pdf

Norman Crowhurst also published his version. Half the article was bitching about how well it worked but that no-one seemed interested in commercializing it.

 

[DonH56]

It took a while for decent high-power switching devices to be developed, along with some circuit design tweaks that got us here today.

Totally forgot about the Crowhurst article, wonder if it is online now?

 

[mhardy6647]

Norman Crowhurst also published his version. Half the article was bitching about how well it worked but that no-one seemed interested in commercializing it.

hmm... I'll have to seek that out. Shouldn't be too hard to find...

 

[mhardy6647]

I once worked for a company that had... a long gestation time for their first successful commercial product (i.e., approved drug).
We used to say our motto was:

Bringing you yesterday's products, tomorrow.

 

[mhardy6647]

so, from that same issue, I just noticed this... which seems oddly appropriate to another thread here.