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Magnovox Phono Console

Beatnik said:
Yep, but I'd have to pull it all and do it again.
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That's OK, each time you change something, you learn... Keep at it til you get what you want!!!!!
Look at my 811 thread, I'm determined to get it to work....
I'm glad you didn't quit before...

Regards,
John
 
I'm attempting to gut the can right now. Probably going to die from cancer trying to get this crap out. Only jabbed my palm twice so far.
 
Beatnik said:
I was hoping to keep it as an integrated, but maybe improve on the existing preamp set up.
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Cool! :thmbsp: Double stacked controls = stereo left and right. Never seen a single bass pot in a stereo before. Usually the volume, bass, and treble controls are double stacked (single for mono), but it is the balance that is a single pot. I haven't studied that schematic yet on why it uses a single bass pot but I am assuming that it has something to do with phasing in one channel. :scratch2:
 
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knockbill said:
Try Mouser...

Regards,
John
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I forgot to mention,,, if you get dual pot controls, try to get good ones, a lot of the cheap stuff won't have equal values on the pots,,, I've been using 2 single pots for VC on my builds, so the channels will be balanced...
Old Allen-Bradley type Js are pretty good, if you can find em...

Regards,
John
 
Following your thread Beatnik.....:thmbsp:

I just picked up a 8601-00....Magnavox last week...about the same as your's but separate tone control unit....on the tuner.

:lurk:
 
cademan said:
Cool! :thmbsp: Double stacked controls = stereo left and right. Never seen a single bass pot in a stereo before. Usually the volume, bass, and treble controls are double stacked (single for mono), but it is the balance that is a single pot. I haven't studied that schematic yet on why it uses a single bass pot but I am assuming that it has something to do with phasing in one channel. :scratch2:
Click to expand...

its actually messing with the input impedance. The way ceramic cartridges work, the lower the impedance they work into, the less bass response you get from them. Basically what this does to cut the bass is create a lower amplifier impedance so the cartridge can't drive it. Its not a proper tone stack by any means. it works for it's original application, and really not much else.
 
Seems the Allen-Bradley is all I found in a 2meg pot and they were past ebay auctions. This stacked pot doesn't exist anywhere I can find.
 
That was a nights work ! Looks like I might get three in there.

Actually wasn't to bad now that it's done. Busted through a hard layer, pulled/dug out a tar like layer and busted out a second hard layer. Clipped that terminal ring thing with the dykes and pulled it out like a C-clip. Dug for a bit some more, then I rammed that flat head screw driver into the remainder pretty far to make two holes and inserted the large needle nose pliers. Gripped the pliers and can and twisted until the guts came out like a screw.

Hoping the terminal piece sets back in like a C-clip when it's restuffed and mounted.
 

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Yeah, this is what I have. I guess I'll just tie all the grounds together and bring them out the center .
 
Beatnik said:
That was a nights work ! Looks like I might get three in there.

Actually wasn't to bad now that it's done. Busted through a hard layer, pulled/dug out a tar like layer and busted out a second hard layer. Clipped that terminal ring thing with the dykes and pulled it out like a C-clip. Dug for a bit some more, then I rammed that flat head screw driver into the remainder pretty far to make two holes and inserted the large needle nose pliers. Gripped the pliers and can and twisted until the guts came out like a screw.

Hoping the terminal piece sets back in like a C-clip when it's restuffed and mounted.
attachment.php
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Interesting! I've always just left the cans and put new caps under the chassis. It's nice seeing pics from doing it this way. I might try it one day...
 
gadget73 said:
its actually messing with the input impedance. The way ceramic cartridges work, the lower the impedance they work into, the less bass response you get from them. Basically what this does to cut the bass is create a lower amplifier impedance so the cartridge can't drive it. Its not a proper tone stack by any means. it works for it's original application, and really not much else.
Click to expand...

Is that why a line level input eliminates bass adjustment, treble control works? Is there a way to make it work with original control set on a phono only amp?
 
I'm on the last cap, I've got five wires/resistors/caps hanging out in mid air I'm supposed to solder together. I'm ready to toss this damn thing to the street right now because it's not happening.

:mad:
 
tom3 said:
Is that why a line level input eliminates bass adjustment, treble control works? Is there a way to make it work with original control set on a phono only amp?
Click to expand...

yes. A line level source is much lower impedance than the old cartridge was. The treble control shunts high frequency to ground, so it will work regardless of source impedance.

I don't think there is any way to make the bass control work outside of using it with the stock phono cartridge setup. Honestly, i'd bypass the whole tone control circuit and the loudness compensation if I were running line level sources but thats just me.
 
I'm not comfortable with all that voltage and stuff to just be hanging out like that.
 

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I'm putting it aside for now. Will eventually order new tube sockets and figure out how to redo this where I feel comfortable with it in the house.
 
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