I got this locally. It works pretty good, but probably needs recapped for better performance. Mostly I'm just curious about it. Obviously it wasn't commercial, and whomever put it together was probably involved in radio stuff because the transformer is for radios that need a bunch of voltages.
One of the bigger transistors is a 2N4921. The other one I'm no sure I can get up to take a peak in the same way.
It's almost impossible to take apart. I mean I cannot actually figure out how it was put together in an order... It's like some kinda weird puzzle. But what I can see is that the board for treble/bass/balance has blue TO-39's??? And a bunch of polystyrene caps it seems.
The lamps turn on during clipping from what I can tell.
I'm hoping someone has simply seen it before.
IMG-0611 — imgbb.com
IMG-0606 — imgbb.com
One of the bigger transistors is a 2N4921. The other one I'm no sure I can get up to take a peak in the same way.
It's almost impossible to take apart. I mean I cannot actually figure out how it was put together in an order... It's like some kinda weird puzzle. But what I can see is that the board for treble/bass/balance has blue TO-39's??? And a bunch of polystyrene caps it seems.
The lamps turn on during clipping from what I can tell.
I'm hoping someone has simply seen it before.
An externally hosted image should be here but it was not working when we last tested it.
IMG-0611 — imgbb.com
An externally hosted image should be here but it was not working when we last tested it.
IMG-0606 — imgbb.com
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I started with one of these in ~1968 but blew it up a few times, and added a input filter to make my a small sub amplifier. I moved the outputs to a heat sink and used larger transistors.
Popular Electronics December 1967
Popular Electronics December 1967
Ah, well then! That was fast.
This one seems to have been running since it was made, but maybe with the light bulb mod for some reason? Was there an article for a bass/treble/balance board?
How did you like it before it blew up?
Thank you for the information.
This one seems to have been running since it was made, but maybe with the light bulb mod for some reason? Was there an article for a bass/treble/balance board?
How did you like it before it blew up?
Thank you for the information.
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Well, he had built one in 1968 and it must have been one of his first DIY amps, so easy to remember.
For the other 34998 Forum Members who have not, a proper sized picture can certainly help 🙄
The hosting site uses a thumbnail as a link but it doesn't work right. That's why I included a link below each picture. The native size was so large you couldn't really navigate the forum part of the page.
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