Magnavox Astro-Sonic Console Info Needed

Bobby Basham wrote:Actually, my unit was a larger version of the original posting, and had three panels in the front...It was one of those Astro-Sonic 100's. It looks like you may have an Astro-Sonic 40 or 100. If you remove the back and find an A575-02-02 (or similar) bolted to the floor, you have a 100.

My 100's are from around 1966 and have the W621 turntables.

Interesting. My catalog from 1968 shows similar models as the "1000 series" with a model very similar to yours called "The Aegean". The numbers stop with the "200 series" being a lower mid-grade model, and although it doesn't even specifically list a 100 series, my guess would be that they were the compact low-end 20 watt consoles that were on the next pages after the 200 series. So when did they add another "0" to the different series numbers? Seems Magnavox was consistently inconsistent through the years...

Here we go again with these numbers.

Mowgli, I don't know what the differences are, but I've pictured a 4-ST686 below. I don't know what the differences are between it and a 3-ST686.

As far as re-stringing the unit, you would need a Sams Photofact/service manual to see the diagram. The stringings below are from three different Sams folders and their dates. For the speaker wiring, there should be a diagram posted inside the cabinet. I had a Maggie with a dead channel, but didn't know it until I played an older LP where the signals were panned hard R/L and the FM wasn't providing a wider separation. Previous owner strapped the left to the right to compensate. A cap job took care of that.

Depending on your chassis, your three speaker terminals could have Channel1/common/Channel2 or Channel2/Channel1/common [1] [C] [2] near the center of the first pic.


I apologize for overloading the Board with pics, but this may be of benefit to some folks.--BB

Bobby Basham
Tucson, Arizona

Thanks for the info Bobby
I've been busy with 6 of them so haven't been online much.
I was going to transplant 10s with horns into the lil Magnasonic.
The lil m-sonic sounds good but the horns' highs are great.
I wound up leaving well enough alone.

I plan to get the biggun restrung and recapped, the side that's right sounds friggin sweet

Copy/paste from my AK post last night in the vinyl only thread

"Did a comparison between different Magnavox consoles today switching between internal speakers and aux out to a different console

Played:
Zappa - Joe's Garage Side 1
Tull - Thick As A Brick Side 2
Jeff Beck - Blow By Blow Side 2
Gordon Lightfoot - Sundown & Carefree Highway
Some Jefferson Starship - Earth
Dave Mason - Only You Know & I Know (trippy marbled disc)
Manfred Mann - Spirits In The Night
Miles Davis - Live At The Fillmore Side 1
Little Feat - Feats Don't Fail Me Now - Side 1

Now I'm going out to swap some 70's Magnavox Astro-Sonic speakers w/horns into a 65 Magnasonic then
AC/DC - Back In Black Side 2
Ringo Ringo Side 1
ELP - Pictures At An Exhibition Complete
Probably Some JC Superstar Brown Album"

Hey sorry to poach the conversation here, I posted in the general board about a similar piece that i recently inherited. If anyone on this site lives in Northern California and wants one of these, or knows anyone who does... feel free to contact me...

I finally got the preamp to the shop.
He recapped it and when I got it home it sounded the same, just better.
The right side is weak, low treble and bleeding between left/right.
It's not the amp or speakers and he's close to baffled.

Bobby, could I bother you for the pix of the the preamp section from your 4-ST686 manual?

Thanks $1M

Okay,

So your preamp/radio chassis is separate from the amp bolted in the lower portion of the cabinet? If so, then your amp may be the problem, or the Tech didn't check some resistors in that preamp section. I've had problems with imbalance, and it was a single resistor that caused the problem.

I've got a Santiago Astro-Sonic 100 sitting here with a dead channel, and I am not in the mood right now. That means I have to check out TWO components instead of all-in-one. The Radio/preamp chassis could be an R207-01-20 and the Amp could be an A575-0-02, and the Changer could be a W620-01-01. These three components have their OWN individual service manuals, so don't use that "1-RP663", etc as a reference point.

If you do have separate components, it may look the like pics below. --BB

Bobby Basham
Tucson, Arizona

Yep, it's a separate amp.
The preamp/tuner and the amp are both at the shop right now so I can't get the model #s off them.
I'll check the #s against what you e-mailed me tomorrow when the tech calls me with them.
I switched the leads between the pre and the amp and the problems switch sides so I know it's the preamp.
Same problem whether phono, TT or CD into AUX.

Glad you narrowed it down to the preamp. --BB

Bobby Basham
Tucson, Arizona

I am having the exact same problem with my astro sonic 3RP658 console. The only way I can get both channels to work, is by plugging my I-Pod directly into the amp to bypass the tuner. Anytime that I run the audio from any device through the tuner, the sound from Channel 1 is almost not even audible. I think that tells me that the tuner is the problem. Does that sound right? If the tuner is the problem, anyone have any suggestions of a good place near Houston, Tx to have it worked on? Also, is it ok to run all four speakers off the 1 functioning channel?

Thanks,
Jeff

Amp = a57502 02
Preamp/tuner = r207-01 10 - I just bought this photofact on ebay, I'll post pix when I get it

I went out and looked at the numbers on my console, and they are the exact same as yours (Amp -A57502 and Pre-Amp/Tuner - R20701). I bet we probably both have the same problem.

Thanks,

Jeff

Sounds like you folks are on the right track. I've got a few pages, don't know where I got them from, issued in January, 1968. It may be a Sams Photofact 679-1.

I am clueless about the the model/run numbers, but the Radio Chassis, Amplifier and Record Player is what you need to go after when repairing these units. That means THREE service manuals, plus a fourth manual if you have a drop-in reel-to-reel tape or cassette deck. I don't know what the differences are between the listed radio/tuners and the amps, but they must be subtle.

This may also help the newbies that may come up in here saying "I bought an Astro-Sonic 1RP679". We'll look at you like deer in the headlights, at least I will...LOL It's not about the outside shell. Similar cabinets can have different components inside.--BB

Bobby Basham
Tucson, Arizona

Someone sent me the R207 radio manual via e-mail

Here are the first 10 pages out of 14:

Here are the rest of the pages for the R207 radio manual:






Enjoy!

Thanks for the service manual, it was a great help. I changed out the C207 Capacitor on the Audio board, and my problem is fixed! I now have audible audio coming from both channels, and also have balance control. The only problem I have now, is that the sound quality in channel 1 is slightly distorted. I think I am going to just replace all the electrolytic capacitors on the audio board as well as all the electrolytic capacitors on the amplifier. Maybe that will clear the sound up. Any thoughts? Anyway, I hope this helps you with your problem. Let me know.

Thanks again!

Jeff