11-21-2017, 08:20 AM
Just to continue the narrative of my research. The date code on this amp places it as March 1962. What was Ampeg doing, making 835s in '62? That's 2 years after the launch of the portaflex series. Probably they were just using up their inventory of parts? It does mean that I posted in the wrong area of this forum, so, sorry about that. 
The more interesting story is the speaker. As mentioned above, it's a bit weird. It's got a date code of February 1962, so it's probably original. But it's stamped as a C15N (a ceramic magnet model), but it has an Alnico-5 sticker on it. It certainly looks like a ceramic magnet. It turns out that it is not unique. I found a thread that discusses a similar situation. Interestingly, the speaker in that thread was pulled out of a '61 portaflex. I guess Ampeg bought a bunch of these. As they were mislabeled, perhaps they got them at a discount? Maybe Jensen simply ran out of the correct sticker? Maybe there is actually an interesting story?
Anyway, I've ordered parts for the power amp. Will report back in a couple weeks with progress.
The more interesting story is the speaker. As mentioned above, it's a bit weird. It's got a date code of February 1962, so it's probably original. But it's stamped as a C15N (a ceramic magnet model), but it has an Alnico-5 sticker on it. It certainly looks like a ceramic magnet. It turns out that it is not unique. I found a thread that discusses a similar situation. Interestingly, the speaker in that thread was pulled out of a '61 portaflex. I guess Ampeg bought a bunch of these. As they were mislabeled, perhaps they got them at a discount? Maybe Jensen simply ran out of the correct sticker? Maybe there is actually an interesting story?
Anyway, I've ordered parts for the power amp. Will report back in a couple weeks with progress.