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Maggie Console Rebuild: Chapter 1: The Premise

Lavane said:
Have you got a drawing of the new PS? I would like to see it. My wife uses a 175 I did but doesn't really want me to in her words "mess with it too much". I would like to put a better PS in it but the rectifier tube has to stay. She doesn't think the SS one I used on the 9303 looks good. :D
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I just have it on my desktop in PSUD2. I'll see if I can't figure out how to screen shot it and attach it to a thread post. If not I'll draw it up. It'll be tomorrow afternoon before I can get back to the desktop. I mostly do the AK thing on an iPad.

If you haven't tried PSUD2 I'd suggest it. If you need a link, let me know, and I can forward the link Mark sent. I'm no expert but once you play with it a little it's pretty easy to set up different choke/capacitor/resistor scenarios to see how they work with your ps and rectifier. I haven't dug too deep but it looks like if you had the desire you could design a full ps with drops to get all your desired b+1,2,and so on. I already know what my drops needed to be so I didn't have the need, but looks pretty cool. Like you could really tweak voltages to optimize tube performance in each stage.

Let me know if you want the link.
 
Thanks! I found the link. I'll have to load it on my desktop or the lappy. I use a pad mostly myself now. I wanted to put a SS PS on her Maggie but she really didn't like the looks of it without the 5u4. There would be plenty of room on the 175 for a second choke.
 
Lavane said:
Thanks! I found the link. I'll have to load it on my desktop or the lappy. I use a pad mostly myself now. I wanted to put a SS PS on her Maggie but she really didn't like the looks of it without the 5u4. There would be plenty of room on the 175 for a second choke.
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If it's just a cosmetic thing with your wife, you could always leave the 5U4 in place and still utilize diodes for your ps. You could probably even leave the heaters attached to get a little heat going. She'll never no the difference.:D
 
Harlon said:
If it's just a cosmetic thing with your wife, you could always leave the 5U4 in place and still utilize diodes for your ps. You could probably even leave the heaters attached to get a little heat going. She'll never no the difference.:D
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I thought about it. But I'm not sure I can get four 470uf caps and two chokes to fit around the 5U4. :scratch2:
 
Lavane said:
I thought about it. But I'm not sure I can get four 470uf caps and two chokes to fit around the 5U4. :scratch2:
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I forgot there are more of the big whopper caps in the SS set up. I don't know how much smaller they are, but when I was exploring mouser for cap options there were a couple they were calling micro caps I think. If they were small enough you may be able to tuck them underneath.
But yeah, for all the space there is on these amps, space is still an issue. I've kind of thrown it to the wind with my separate chassis ps, but there's also the desire to maintain the "primitive beauty" of these amps in their original configuration.
I'm still sticking with the paraphase splitter topology in the front end of the amp. I wonder sometimes with all the other changes I'm planning if shouldn't just start from scratch and build on a new chassis. Respacing the tubes, OTs, etc,..., to streamline everything.
That old question, when does it stop being a Magnavox?
 
6DZ7 said:
I'd say when it starts to become a "Harlon."

How much of a Maggi, or any other brand for that matter, is proprietary design? Most amps have 90% or more of their makeup based on standard circuit components and voltages. When does any amp become the manufacturers design? The sum of the parts? Maybe a "refinement," no one else uses. Patented circuits? if so, then it stops being a Maggi when the original sum is changed. It becomes a "Harlon," as soon as you make a change of those features.. On the otherhand if what makes it a Maggi is the iron and nothing else, then changing that makes it a "Harlon.'
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Very well put. :thmbsp: I have several Marantz components that I restored with factory spec. Parts because I didn't want to change the signature sound. Not to mention it would hurt the value. But then I have others that were really nice designs but are more common. And with better parts like film caps, different cap values, better diodes, transistors ect. It really made them shine!
 
6DZ7 said:
I'd say when it starts to become a "Harlon"
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My college freshman would love that. I need to go copyright my name quick. In case I ever get good enough at this stuff to put out my own signature line of amps. Everyone's going to want to get their hands on "The Harlon!" The top of the line Hi-Fidelity unit will be the "Big H" as my boys friends call me, and the entry level model will be the "Little H" as I call my oldest who has Harlon as his middle name.
Ahhhh, I've finally found my inspiration.
 
Nice,
And by the way, Levane, I'm going to be a little while on the schematic. My little charge is home sick so I most likely won't get to the desktop today.
 
Harlon said:
Dude, such disrespect. We're talking about a Harlon original here. You can't even change the caps or you'll spoil the original intent of the designer. :banana::banana:
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I really don't change too much of the amp sections. Split the cathodes, ditch the hum pot and better feedback circuit. As for the PS, I like um quiet, whatever it takes. And if your going to do what you said you are going to do there is nothing to change. :thmbsp:
 
9304-20 Power Supply

Attached is a diagram of the PS in PSUD2. It doesn't contain the final RC section of the Smoothing section but you know how that looks.
 

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