TOTL Magnavox Astrosonic Console w/ audio problems

captainclock

Pacifist Otaku
Hi everyone, today I visited a friend of mine from church who has a neighbor who had recently bought from an estate sale a top of the line Magnavox Astrosonic Console Stereo from around 1965 with automatic tuning and a remote controller to control the stereo's power and volume.
When my friend's neighbor had bought the unit it was hooked up at the previous owner's house to a whole-house speaker system with the stereo playing through it plain as day but then when the stereo was disconnected from that whole-house speaker system so that the stereo could be transported to my friend's neighbor's house (well garage) my friend's neighbor discovered that the original internal speaker wires were cut and spliced by the previous owner so that it could be wired into the whole-house speaker system that it was wired into previously.
Anyways my friend's neighbor disconnected the old whole-house speaker system hookups from the amplifier connections and rewired the built-in speakers like how the schematic on the back of the console had indicated they should of been wired up, but when he did that he went to power on the system and there was no audio coming out of the speakers (which the speaker system this unit uses is the TOTL 15" Woofer and Mid horn and Horn Tweeter set up that Magnavox was known for in their TOTL consoles) and I took a look at the unit and monkeyed with the connections and I can't really seem to get it to do anything either, I even checked the crossover circuit and it seems to have never been touched, and all I can figure out is that there's a pushbutton switch on the top of the tuner/preamp assembly that sits next to the balance control knob that's marked "Push-On Volume" and when I pushed the pushbutton control switch there would be audio coming out of the speakers but it would be nothing but static and no audio from the tuner or the turntable just a loud, crackly, staticky noise and when I would let up on the pushbutton switch the stereo would go back to being silent again.

Does anyone have any experience with this particular console and some of its quirks, or what could be wrong with this stereo?

Any Help would be appreciated.
Also sorry about there being no pictures, its in the guy's garage and I had no way to take any pictures.
 
In 1965, if it didn't say Concert Grand, it was likely an Imperial, the next line down. Still very ritzy for 1965 and still high end in Magnavox. I hope you get it sorted, a very nice Magnavox. Expensive when new,
 
Yeah I would love to help this guy get it going again as from what I could see of it it was definitely a very nice unit. I think if I remember right I think the sticker inside the cabinet said something about concert grand on it, but not sure. It definitely had some burned out dial lamps and a burned out FM Stereo lamp.
 
FWIW, the wiring diagram on my 1962-63 Maggie AstroSonic does not match the actual wiring. IF your friend's is somewhat similar (I have a 1ST635) the crossover only applies to the tweeters, so the inputs go to the crossover, but the woofers will then exit before the cross, while the highs will come out the other end. On the return, it gets a bit tricky, as it seems that the only priority is to actually get all the grounds back to the amp, regardless of what they go through or around to get there. I had to pull the speakers and crossover out of the box and lay them all on the floor connected to an amp in order to get the electron paths figured out.
 
I wish I had one of these near so I could give you some idea where the wiring goes. I seem to recall thaxman's approach is correct.
 
Thanks, I'll be going back to the guy's house tomorrow to take another shot at it, (yesterday I didn't have much time to thoroughly go over every single detail of the wiring because I had another commitment I had to get to and tomorrow I have a free day so I should be able to spend a good several hours looking things over.) The model this gentleman has is the model where the cabinet looks like a lowboy style dresser on the front side and then it has the remote that came with it, and has Automatic tuning where its supposed to be able to tune in stations for you at the push of a button on the cabinet or the remote. I think its a Concert Grand unit but like I said I can't remember, it also has the amplifier seperate from the preamp/tuner section of the unit. Then on top of that it has a seperate amplifier unit for the microphone pickup for the remote control unit which is rather impressive because I think it might be actually a phono preamp stage modified to be used for a "remote amplifier" which I think if one wanted to one could take and remove the microphone from the unit and modify the "remote amp" back into a phono preamp and make the unit so that it can have a Magnetic Cartridge on the Record Player. :scratch2:
 
Add a phono preamp. Hacking up the remote is disrespectful and devalues the Concert Grand. They are now valued. And it was never used as a phono preamplifier. It was used as a remote control amplifier.
 
Add a phono preamp. Hacking up the remote is disrespectful and devalues the Concert Grand. They are now valued.

Alright, that's fine, I was mostly just wondering if it was something that could be done but I'll just leave it be.
Anyways like I said the previous owner of the unit had cut and spliced wires and cables into the original internal speaker wiring coming from the amp (where he had basically just had the speakers in the cabinet disconnected from the amp completely with just the wires going from the amp just being in place) and had from there the console wired into a whole-house speaker system instead of just using the external speaker terminals and leaving the internal wiring alone.)
Which I think that the previous owner's whole-house butcher job is partially responsible for what happened with this stereo not wanting to put out any sound through the built in speakers, because the guy that owns it now admitted he wasn't electrically inclined and he just wired up the wires for the built-in speakers the way it looked like it should of gone to the amplifier wires, and I'm wondering if there might of been a circuit protection fuse or two on the amplifier that might of blown when the original speakers were wired back up but not on the correct terminals (kind of like some of your high end receivers have.)
That's about the only other explanation I can think of as to why the amplifier wouldn't be putting out sound anymore.
 
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I'd start with hooking speakers to the marked output tabs on the head unit itself. Simple hookup, left, right, and center is ground. Make sure the remote connections in the center of the receiver are correct, or jumpers are in place there. Put a signal into the aux/tape inputs too.
 
I'd start with hooking speakers to the marked output tabs on the head unit itself. Simple hookup, left, right, and center is ground. Make sure the remote connections in the center of the receiver are correct, or jumpers are in place there. Put a signal into the aux/tape inputs too.

Alright, I'll have to bring my "sacrificial" pair of speakers along (either that or pick up a pair of "sacrificial" speakers at goodwill) so that I can then wire them up to the unit to see if the amplifier/console itself is actually capable of producing audio without the confusion of the internal/built-in speaker wiring mess (which I will need to some how sort out if I do find that the amplifier is in proper working order.) And if I do find that the amplifier in the console is in proper working order then I would be time to take all of the speaker wiring including the cross over unit and speakers out of the cabinet and then try and sort out all of the speaker wiring mess inside the cabinet with the speakers hooked/wiring hooked to the amplifier itself. And also I may need to test the speakers themselves with the ohmeter function on my multimeter to make sure the speakers themselves aren't blown (which if they are that might explain why the previous owner of the unit disconnected the built-in speakers and wired the unit up to a whole-house speaker system.) Although lets just hope that the original speakers aren't actually blown. :yes:
 
I'd start with hooking speakers to the marked output tabs on the head unit itself. Simple hookup, left, right, and center is ground. Make sure the remote connections in the center of the receiver are correct, or jumpers are in place there. Put a signal into the aux/tape inputs too.

Alright, I'll have to bring my "sacrificial" pair of speakers along (either that or pick up a pair of "sacrificial" speakers at goodwill) so that I can then wire them up to the unit to see if the amplifier/console itself is actually capable of producing audio without the confusion of the internal/built-in speaker wiring mess (which I will need to some how sort out if I do find that the amplifier is in proper working order.) And if I do find that the amplifier in the console is in proper working order then I would be time to take all of the speaker wiring including the cross over unit and speakers out of the cabinet and then try and sort out all of the speaker wiring mess inside the cabinet with the speakers/wiring hooked to the amplifier itself. And also I may need to test the speakers themselves with the ohmeter function on my multimeter to make sure the speakers themselves aren't blown (which if they are that might explain why the previous owner of the unit disconnected the built-in speakers and wired the unit up to a whole-house speaker system.) Although lets just hope that the original speakers aren't actually blown. :yes:
 
UPDATE: I went over to the guy's house today and worked on the unit and I figured out that the amplifier has no issues and that the amplifier works fine but apparently it seems that the problem resides in the tuner/preamp section of the console itself because apparently when I went to try and adjust the volume of the amplifier with a CD Player as the source the loudness/volume control wasn't working and wouldn't adjust the volume of the amplifier and so I took the preamp and the amplifier out of the cabinet to take it home with me to see if I could do some additional troubleshooting at my house and for some reason I can't seem to get the dumb thing to power up now and I have everything that needs to be there for it to power up hooked up to the thing except for the record player and the remote amplifier which I wouldn't of thought that one would of needed the remote control amplifier and the record player to power on this stereo... Any ideas?

Also it seems like there also might be a problem with the motorized tuning mechanism as well but I have no idea how to go about repairing it or troubleshooting it as this is the first time I've ever dealt with a system this complicated before any ideas? Also I saw the model of the unit on the cabinet it was a 1ST6xx model and the date stamps I'm seeing on it put it around 1965 like was thinking (7/64 were some of the date stamp markers I was seeing on the cabinet and on the chassis.)
Anyways like I said any additional assistance would be greatly appreciated.
 
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Picture of the outside of the unit...

Just thought I'd show you some pictures of the unit I'm currently working on, its not of the actual unit itself but of one that is the same model but was a picture I located online. I also will upload the guts of the unit as well.
 

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Maybe not, but if that is anything like mine, it has RCA jacks on the chassis that are marked REM OUT. These go to the power amps main inputs.

If you didn't know how to bypass that remote control, you would have needed it as it is connected in the chain between the main power cord and power switch. If you can get the amp to power up on its own then you should have power to the tuner/preamp.

These early types of remotes only had 3 or 4 steps rotated by a relay motor. You would have "OFF" then "ON LOW" then "ON MED" then "ON HI" or MED HI then HI then OFF again.

The motorized tuning on mine works but just continues up and down the dial until I attach an antenna, then it will stop at every station.
 
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Maybe not, but if that is anything like mine, it has RCA jacks on the chassis that are marked REM OUT. These go to the power amps main inputs.

If you didn't know how to bypass that remote control, you would have needed it as it is connected in the chain between the main power cord and power switch. If you can get the amp to power up on its own then you should have power to the tuner/preamp.

These early types of remotes only had 3 or 4 steps rotated by a relay motor. You would have "OFF" then "ON LOW" then "ON MED" then "ON HI" or MED HI then HI then OFF again.

The motorized tuning on mine works but just continues up and down the dial until I attach an antenna, then it will stop at every station.

So it seems I may need to put the whole assembly back into the cabinet again... the only problem is that I may have accidentally broke the original tuning meter that went with this console and have no idea where to source a new one at. Also the power switch for the remote control function, doesn't seem to work (the large switch in the lower right hand side of the picture of the front of the tuner/preamp assembly) because when i go to push in on it the switch only stays on momentarily and then shuts back off again when my finger is let off the knob, also neither the "remote" volume control (the volume control on the remote power switch) nor the volume control on the preamp will work... so yeah, not sure how to go about troubleshooting that issue...
 
I just picked up one of these in pretty good condition,the back is off and I can get digitals of any area you need.All functions working on mine,but have to power off to stop automatic tuning!Thing just keeps rolling!Backed up to exterior block wall,so I suspect I need a better location and or antennae.Mine didn't have the remote with it...I still haven't cleaned it,sounds really nice tho!
 
I just picked up one of these in pretty good condition,the back is off and I can get digitals of any area you need.All functions working on mine,but have to power off to stop automatic tuning!Thing just keeps rolling!Backed up to exterior block wall,so I suspect I need a better location and or antennae.Mine didn't have the remote with it...I still haven't cleaned it,sounds really nice tho!

yeah I saw the thread for yours. the one I'm working on doesn't want to put out any audio and the autotune/motorized tuning feature doesn't seem to work at all on the one I'm working on althout it has its original remote and two mounting brackets for the remote because when I go to activate the power switch for the motorized tuning all I hear is a buzzing noise and that's it, the dial doesn't move or anything.
I suspect that there is something wrong with the tuner/preamp circuit that's not allowing it to produce any audio because I hooked a CD Player up to the Amplifier through the input jacks and played through the amplifier and the amplifier works but when I went to adjust the volume using the loudness adjustment and the volume wouldn't go up or down it just stayed the same which is why I suspect that there's something wrong with the preamp/tuner circuit that's causing it to not send out an audio signal to the Amplifier.
 
I have some push-button controls on the left side of my tuner,the on off loudness is giving me some noise.I really need to dismantle and clean mine.It really overall sounds great,even with the backs off the speaker boxes.I recommend you put some effort into fixing yours,but if you can't,I know someone seeking the remote!
I'd love to see some pics of your console.I'm not sure if I have the Imperial or the Concert Grand.I'd love to find out what reel to reel unit came with this also.Do you have any paperwork with yours?
 
Okay,the pushbutton switch in question is a 3 way pushbutton switch.Get to it,clean it.work it through several times,compressed air,de-ox again,work it more.I'm thinking your not working it through all circuits...
 
Okay,the pushbutton switch in question is a 3 way pushbutton switch.Get to it,clean it.work it through several times,compressed air,de-ox again,work it more.I'm thinking your not working it through all circuits...

OK, I'll see what I can do concerning trying to clean that push button/rotor switch and as for whether the one that my friend's neighbor has (its not actually mine I'm just working on it for someone) all it has is the old paper labels from the back of the cabinet showing the wiring of all of the components including the speaker system, and that's it because I guess the original owners manual was lost long ago by the previous owner of the unit who had apparently bought the unit new back in 1965. Although it kind of surprised me that it still had its original remote with it yet but not its original owners manual and what not...
 
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