Magnavox Console 1ST659A

[2E151]

Okay guys, I picked up my first console about a month ago. It's a Magnavox 1ST659A (gleaned from operation manual). After cracking the back off I noted the tubes on the amp; 5U4, 6BQ5 x4, and 6Eu7 x2.

Bought it out of a local antique shop for about a hundred bucks. At the time they were playing a local station on it and said the turntable needed a new needle.

In its current condition I listen to the radio on it for short periods of time, which sounds pretty good. Sometimes I have to tweak the volume knob back and forth to get things right. It sounds better on FM rather than Stereo FM. The volume gets noticeably weaker on Stereo FM.

I recently put a new needle on the turntable and it sounds good, but not great. The auto-changer works like a charm, but it just doesn't sound quite right. Some songs sound better than others, but I can hear the difference as clear as day on the clarinet opening of Moonlight Serenade. That's pretty much the benchmark I judge record players by.

Anyways, as this is my first piece of tube electronics I wanted to stop by and see what you guys have to say about this console. Any insight you can give my will be gladly welcomed! As you can see it's the crown jewel in my office and I doubt I'll ever settle for anything else than an auto-changing tube amplified console now

 

[truetone36]

If you're going to use it regularly you should recap it as the old caps have most likely drifted off spec a bit. Start with all electrolytic and filter caps.

 

[2E151]

Hmmm, never attempted anything like that before.

 

[larryderouin]

It's not that hard. If you can read a schematic, and know which end of the soldering iron gets hot you've got it licked.

Basically you want to replace all the electrolytic capacitors on the amp, and to a lesser extent the tuner/preamp. The caps will look like barbie sized soda cans except for the Main Filter caps which are the two large chrome colored or have a cardboard cover.

Make a list of ALL the lytics on the AMP. Write down the capacitance, expressed in UF, or PF (That old would be UF, and MMF which is same thing ) and the voltage.

The stock values have changed since yours was built so you are gonna find that your caps are odd sized as far as values go. NO PROBLEM!!!

Exchange Rates.
20uf/10V = 22uf/10V or 16V
50uf/15V = 47uf/16V or 56uf/16V or 20v

Just go up to the next available value.
The only value I would go down to would be 47 on a 50. It's 5% which is well within the old spec for tolerance. Usually -20%/+50 to 80%.

The caps UNDER THE BOARD are AXIAL's for the most part (meaning a lead at each end), where the ones on a board or the BIG FILTER CAPS are RADIAL. Underneath you can use either, but be prepared to run some wire if you use radials due to lead length.

Replace ONE CAP AT A TIME! Don't Depopulate the whole board, and come back and expect to remember where everything went. YOU WILL BE SCREWED UP! Just do one at a time without a break. One lead off, New lead on, old cap out, new cap in! OBSERVE POLARITY! It's actually Easier than it sounds. And then there's always the 1st time. Bet you were scared when you changed your plugs the first time, weren't ya? Change a tire? 1st time was a hair raiser! On a hill with a trailer attached. After the 1st one, the rest are cake!

Make a list. Double check. Order them from Mouser or Digikey. Personally I find Mouser's ordering pages for caps a cinch. Get Nichicon UPW SERIES. Inexpensive and a good cap. Say you need a 470uf/50V cap. Type in search 470uf 50V upw. If there is a Nichicon UPW series in that value, it will come up and you just put in # wanted and add to cart.


One or two other things. Pull the Tuner and preamp out and DE-OXIT the hell out of the pots. They definately need it. I have 4 Maggie's and they all needed it from the gitgo. My 1p3700(1967)is the worst. I have to replace the cap on the attenuator for the Bass as I get a pop when I go from 1st detent to the 2nd(no bass pot). The bulbs are 1847 or 47 (SAME BULB, Radio Shack has them).

There may be a Stereo separation pot on the preamp. MOST all Early 60's "STEREO's" were origianlly designed as MONO and modified to run stereo. They split the signal and added a mixing pot. When the designs changed about 65 the Mixing pot (separation control) got the boot. It's more of a BLEND from PURE 2 Channel to PURE MONO sound out of 2 speakers. As you get to PURE Stereo, the mixing is cut off and the volume goes down. Find a balance between separation and volume you can live with. You will need the manual for it. Mike at Vintageaudiomanuals.com shoud have a manual for the 1st659. If he does it will encompass the TUNER,PREAMP,AMP, and TURNTABLE. Magnavox is listed in the "OTHER" section and has 14 folders.

Go over to the Turntable FORUM. Search Micromatic TEARDOWN and REBUILD. I tore one of mine down and rebuillt it. Basically a cleaning and re-lube. You'rs may have the DUAL IDLER but that would be the main difference. They are all similar in operation and parts location. Also check the wires for the tonearm. There are 3. Right-common-Left.

AND CHECK that the speakers are wired correctly. That can account for the STEREO sounding weak. Again 3 wires RIGHT- COMMON(GROUND) - LEFT.

I have a SM on pdf for the 602-620 series Micromatic if needed. Look on the underside of the Phono base for a tag that will tell you which model you have.

Have Fun.

Larry.

 

[relaximus]

Wow Larry, nicely done. This needs to made a sticky!!!

Dave

 

[SpruceMoose]

"and know which end of the soldering iron gets hot, you've got it licked"

might want to re-phrase that a bit. don't lick the hot end! sounds painful

 

[larryderouin]

ROFLMAO!!!!!!! I didn't think about it THAT WAY! But if you want to clean the tip of your iron with your tongue, go right ahead!!! I just choked on my Coca Cola!!!! Hold on one........Back with a damp rag to clean off my laptop!!!!

I'm still waiting for the Micromatic Teardown to become a sticky a year later.....And I'm gonna Win Mega Ball the next time it's over 50 Million! YEAH RIGHT!

Larry

 

[DanO55]

Ever see some one strip a piece of wire with their teeth--- with the power on? Now that entertainment.

 

[2E151]

Thanks for all the great info!

Here's a real stupid question: The screws that hold the table to the console, the ones with the thick rubber washers at the bottom. Whats the secret to the metal latches/catches on the bottom? Got one off, dunno how, and I'm trying to figure how to get it back on before I remove the last two and get myself in a real bind.

 

[RWood]

It sounds better on FM rather than Stereo FM. The volume gets noticeably weaker on Stereo FM.

Not to overwhelm you, but I can give you an easy fix for this condition, and yes, it involves a capacitor.

Your tuner has a "multiplexer" that decodes the stereo signal. Depending on your model, the MPX will either be a separate unit (a third, little chassis) OR contained on the actual tuner board. In both cases, the MPX circuit has a 12AT7 tube. To pin 8 of that tube is a 4uF electrolytic capacitor, low voltage. Replace that with a 4.7uF ($1.79 from Radio Shack) and your FM Stereo will jump back to life!


RWood

 

[Bulltexan]

Turntable latches

The "latches" flip down to unlock the table from deck..See pics>>locked/unlocked
You have to have the back off to access the crawl space,,and the one in front
is hard to get to..Use a flashlight and something long to reach in and flip down.
Locks will go thru holes then.
Unplug it first,(power),unlock both latches,,then lift straight up,,unplug rca"s

I went to a thrift shop run by a crisis center for women,,and they had a 1st606B
that was playing on one channel.
I asked "How much",,and wound up with it for 8 bucks..
Its in rough,,but re-furbible condition(another project)
The one channel that played cranked up loud!! And found a bad 6ue tube.
I swapped it with the good and both sides work,,after finding the balance UNDER the volume knob(double pot)
I hope mine looks that nice when I am done(lots of fun work)
Am looking forward to this thread..

 

[2E151]

!Oh! Heh, I though the screws were supposed to come out. My bad, I guess I need to put that one back on. The rest of them flipped up just as you said.

 

[ManFromPorlock]

One more thing when replacing caps: make sure the caps are discharged before you work on them. Especially in tube systems, caps can store enough energy to give a serious shock.

 

[2E151]

Is there a particular way to go about that, or do you simply leave it unplugged for awhile?

 

[larryderouin]

short them with a 60W light bulb with 2 leads attached. Wait 30 seconds and verify with a volt meter. The Larger ones will require more time than the smaller value ones. or a large wattage resistor, I don't remember what size across the leads of the cap.

Larry

DANO55: Shades of that Goofy Radioman on down Periscope! Now THAT was FUNNY!!

 

[wa2ise]

As for recapping: Take a look at my page http://www.wa2ise.com/radios/repair.htm and at http://www.antiqueradio.org/recap.htm though I would not try to remove the old caps' leads from terminals. Terminals are rather fragile, and you really don't want to break one off a tube socket or switch or pot. Those caps in white ceramic tubes are paper caps and will need to be replaced, as well as any wax dipped caps.

 

[2E151]

Anyone have any idea what cartridge this mircomatic will take? The needle doctor lists 3 or 4 and i don't know which is which....

 

[larryderouin]

Unscrew the old cartridge from the headshell. The #'s should be on the top.

Larry

 

[2E151]

Hmmmm, looks to have 660310-1 on the top and 535 on the side. Very puzzling, as this doesn't register on any website I can see...

 

[larryderouin]

Cartridge is a 560310-1. stylus is 365.

Go to http://www.turntableneedles.com
1.) click "FIND MY PLAYER" Click "by MANUFACTURER"
2.) Click the dropdown and find MAGNAVOX;Collaro
3.) in the next dropdown find 1st659A.

It will show you two needles a 359 and a 365. Match the body of yours up with your needle.

You could also get a whole new cartridge, there are a boatload of ceramics on the sight, but at the prices they want, you'd be better off buying a magnetic, and a preamp unless you want to keep it 100% authentic.

Larry