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Re: Magnavox Astro-Sonic Console Info Needed
Posted: Thu Apr 28, 2011 5:40 am
by Mowgli
The tech told me he used a different source to feed the amp.
He fed one of the amps inputs and it stayed all to that side.
He fed the other input and it bled "like 20%" to the other side.
So the problem is definitely in the amp since he didn't use the preamp.
He says the amps are two separate units but something has to be shared for them to bleed sound to the other.
transistors? caps? what's shared?
Bobby you get a scanner yet?
Anyone have the schematic for amp # a57502 they could share?
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Thu Apr 28, 2011 7:10 am
by MattTech
Mowgli wrote:The tech told me he used a different source to feed the amp.
He fed one of the amps inputs and it stayed all to that side.
He fed the other input and it bled "like 20%" to the other side.
So the problem is definitely in the amp since he didn't use the preamp.
He says the amps are two separate units but something has to be shared for them to bleed sound to the other.
transistors? caps? what's shared?
Bobby you get a scanner yet?
Anyone have the schematic for amp # a57502 they could share?
This "tech" (if that's what he really is).... by now I'd have gotten another one.... someone more "qualified".
The only thing in the signal path that is "common" to both channels is
IF the chassis has a preset balance pot on it, it's most likely defective and could be replaced by common 100 ohm resistors. (most 500 series amps have onboard balance pots)
A qualified "tech" such as I, would have determined that by proper troubleshooting, not picking and hunting, and guessing..... for months.
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sat Apr 30, 2011 9:24 pm
by FreeLantz
Ok folks to return to the topic of my Astro-Sonic...
I bought a needle for it on Ebay a few months ago (around the time I made this thread) and finally started looking at it yesterday to see how to remove the old one and replace it. I am clueless. I can't see anything to push or pull to remove the old needle. Can anyone help? I can post more pics if needed....
Thanks!
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 2:36 am
by MattTech
FreeLantz wrote:Ok folks to return to the topic of my Astro-Sonic...
I bought a needle for it on Ebay a few months ago (around the time I made this thread) and finally started looking at it yesterday to see how to remove the old one and replace it. I am clueless. I can't see anything to push or pull to remove the old needle. Can anyone help? I can post more pics if needed....
Thanks!
Ya see that little flip lever for LP/78?
That whole deal gets pulled off the cartridge and a new one snaps in.
Easy.
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 3:45 am
by misc1600
I have the same model has the one below. Does anyone have info on what Needle and Cartridge I would need to fix this? This is my first record player, so I have no clue what type I would need. I was wondering if you know this type or if I need to take pictures.
viewtopic.php?f=15&t=3970
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 5:12 am
by Ron Rich
Look in the FAQ's in phonographs
Ron Rich
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 5:19 am
by misc1600
Ron Rich wrote:Look in the FAQ's in phonographs
Ron Rich
Thanks. Went to Needle Depot and found it. Thanks
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 5:24 am
by Ron Rich
It is THE FIRST topic in the "Electronic Gramophones & Phonograph" section?
Ron Rich
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 5:46 am
by FreeLantz
MattTech wrote:FreeLantz wrote:Ok folks to return to the topic of my Astro-Sonic...
I bought a needle for it on Ebay a few months ago (around the time I made this thread) and finally started looking at it yesterday to see how to remove the old one and replace it. I am clueless. I can't see anything to push or pull to remove the old needle. Can anyone help? I can post more pics if needed....
Thanks!
Ya see that little flip lever for LP/78?
That whole deal gets pulled off the cartridge and a new one snaps in.
Easy.
Thank you sir. I do see the lever. I am probably looking at this and expecting it to be more difficult than it really is.

But I will spend some time and figure it out tomorrow.
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 5:51 am
by misc1600
What is the difference between the Astatic N79 vs. Astatic N83?
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 6:36 am
by Bobby Basham
For some reason, I keep a spare cartridge near the computer...LOL! If you have the cartridge out, lying on its back, lift the 78/LP lever slightly upward then pull it out. You just can't pull it straight forward. Insert the new needle the same way at an angle and slide in until it clicks/snaps into place. It will now be fully seated. The metal clip is in the very center of the pic. You'll find that with most ceramic cartridges made back in the day. --BB
Bobby Basham
Tucson, Arizona
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 9:41 pm
by FreeLantz
Thanks for the photo! That was especially helpful since I am dealing with this "upside down" as I don't want to disconnect the cartridge. Now I know how to change the needle. Unfortunately the new one I bought doesn't fit. It has just a slightly different shape and won't lock into place firmly. So at least I was able to get the old one back in for now and I'll have to keep looking for the correct needle.
A lot of dust fell out of that thing when I removed the old one..... I think that was causing the "tisking" sound I was sometimes hearing.
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Sun May 01, 2011 10:00 pm
by FreeLantz
Gosh, reading back through this thread I guess I
am going to have to disconnect the cartridge to determine what needle I need....

Re: Magnavox Astro-Sonic Console Info Needed
Posted: Mon May 02, 2011 1:18 am
by shedradios
Freelantz, IF you have a cartridge as in Bobby's picture (EV 275), here's two needles which will work: 368-DS77 and N2-DS. For anybody one way to help locate a needle without a cartridge number on Ebay is to include the model number of the set in a search to include in description. Ebay prime sellers go to great lengths to include model numbers in their description.
Re: Magnavox Astro-Sonic Console Info Needed
Posted: Mon May 02, 2011 2:42 am
by Bobby Basham
There you have it... --BB