akimball442
New Member
So my old Eico ST-70 which I have had for years, recapped once (years ago) has gotten to the point where it's not worth saving.
When I received it, it had been kept in a garage for about thirty years, and the chassis was rusty. I did the best I could to save it, but at this point, I've decided the chassis is a lost cause and this amp's iron will be better off living on as something else.
So I am also a big fan of Magnavox amplifiers, and have discovered that I can mount the Eico transformers on an old Maggie 142 chassis in such a way that they will be oriented and spaced just like the Eico. Perfect.
Since I like the Eico very much, I'm going to duplicate the power amplifier almost exactly.
But I'm wondering about the power supply. I'll no longer be needing a lot of it, everything for the preamp can go- I suspect I may have to adjust some resistor values to compensate.
Having looked at many other schematics (including many of the Magnavox amps) the power supplies often include a choke. Although I've learned a lot working on these things, and understand the basic function of the choke, I'm wondering if someone could explain to me the advantage or disadvantage of adding one, whether it'd be worth doing or not, and how I would calculate the value?
I look forward to hearing what you guys think.
Schematic borrowed from the internet...
When I received it, it had been kept in a garage for about thirty years, and the chassis was rusty. I did the best I could to save it, but at this point, I've decided the chassis is a lost cause and this amp's iron will be better off living on as something else.
So I am also a big fan of Magnavox amplifiers, and have discovered that I can mount the Eico transformers on an old Maggie 142 chassis in such a way that they will be oriented and spaced just like the Eico. Perfect.
Since I like the Eico very much, I'm going to duplicate the power amplifier almost exactly.
But I'm wondering about the power supply. I'll no longer be needing a lot of it, everything for the preamp can go- I suspect I may have to adjust some resistor values to compensate.
Having looked at many other schematics (including many of the Magnavox amps) the power supplies often include a choke. Although I've learned a lot working on these things, and understand the basic function of the choke, I'm wondering if someone could explain to me the advantage or disadvantage of adding one, whether it'd be worth doing or not, and how I would calculate the value?
I look forward to hearing what you guys think.
Schematic borrowed from the internet...