Motorola console record player - Videokarma.org TV - Video

radiotvnut · #1 02-28-2014, 11:41 PM

Someone locally has this Motorola for sale for $50 and they have no idea if it works. I'm sure it's a tube model; but, I wonder if it has the big amp or a suitcase portable record player amp? The cabinet style makes me think it might have a decent amp in it.

davet753 · #2 03-01-2014, 08:58 AM

Motorola's of that era were generally a pretty well-built piece of equipment. That one looks like it would clean up quite nicely.

radiotvnut · #3 03-01-2014, 01:19 PM

I have the Motorola (1963 model) and it is a 3-channel model with PP-6V6's for the center 12" speaker and a single 6BQ5 for the L and R speakers. The changer is a standard VM with a floating Euphonics cartridge. The cabinet has some minor veneer damage and is very dirty; but, I think it will clean up OK. The owner was kind enough to deliver the stereo without charging me for gas and he also gave me an early '70's portable stereo 8-track player/radio; so, I didn't attempt to talk him down on the price and I gave him the $50.

Robb · #4 03-01-2014, 02:10 PM

Id offer $25.00 but I guess you bought it already.
If you can clean it properly and restore it, you may get $100 for it.

radiotvnut · #5 03-01-2014, 02:34 PM

I might keep it. This one was made in '63, the year my house was built; so, it would certainly be "period correct" for my house.

Robb · #6 03-01-2014, 02:37 PM

Cool Id like to see it restored.. maybe throw some Howards feed n wax on it.

dieseljeep · #7 03-01-2014, 03:18 PM

Quote:

Originally Posted by radiotvnut

I might keep it. This one was made in '63, the year my house was built; so, it would certainly be "period correct" for my house.

It's kind of a strange control layout. The large knobs are for the bass and treble, while the small knobs are for the loudness and balance.
It might be the smaller amp, like found in their TOL portables. Probably, not PP on the center channel, but single 6BQ5 and 6BM8's for the right and left channels. If so, it's still better than some of the competing models, built by other firms.

radiotvnut · #8 03-01-2014, 04:53 PM

dieseljeep · #9 03-01-2014, 07:40 PM

Quote:

Originally Posted by radiotvnut

I have the Motorola (1963 model) and it is a 3-channel model with PP-6V6's for the center 12" speaker and a single 6BQ5 for the L and R speakers. The changer is a standard VM with a floating Euphonics cartridge. The cabinet has some minor veneer damage and is very dirty; but, I think it will clean up OK. The owner was kind enough to deliver the stereo without charging me for gas and he also gave me an early '70's portable stereo 8-track player/radio; so, I didn't attempt to talk him down on the price and I gave him the $50.

I hate to think, that I was wrong again, regarding the amplifier. Unless there is a sub-chassis, with the pre-amp stages, the left and right channel tubes should be 6BM8's. There's nothing wrong with that, AFAIC.
The output transformers for the left and right channels are a little skimpy, but surprisingly, they did a good job.
Thanks for the pictures. As the old saying goes: One pictures worth a thousand words.

radiotvnut · #10 03-02-2014, 12:30 AM

If the techpreservation site would behave, I could pull up the schematic and see what's going on here. There is no other preamp chassis; so, the main active components are on the big chassis.

davet753 · #11 03-02-2014, 04:26 PM

Quote:

Originally Posted by Robb

Cool Id like to see it restored.. maybe throw some Howards feed n wax on it.

That stuff is great!!!!

I bought a bottle on Amazon a few months ago, and I've used that on every piece of furniture in my living room. I have a Magnavox Astro-Sonic console that I had cleaned up with some Fuller Brush wood polish, and it looked good.....but rubbing it down with some Howards Feed-N-Wax made it shine like a new dime.

I also have a Columbia Grafanola crank-up record player that the cabinet has been stripped. It even made that wood shine!

dieseljeep · #12 03-02-2014, 07:39 PM

Quote:

Originally Posted by radiotvnut

If the techpreservation site would behave, I could pull up the schematic and see what's going on here. There is no other preamp chassis; so, the main active components are on the big chassis.

It probably has the 6BM8 tubes for left and right channels. It's a triode-penthode type of tube. Also, it uses the 5BC3 novar type rectifier tube. Same as a 5U4, with a novar base.

DavGoodlin · #13 03-03-2014, 02:01 PM

Motorola value! Thats a fairly simple amplifier; with each 6BM8 pentode driving mid-high speakers at 5-watts, and
each 6BM8 triode serving as the preamp for the ceramic cartridge.

The 6BQ5's grid then has to be driven with both channels to push about 10 watts to the woofer. I wonder how that is done, summing the L+R channels to feed the 6BQ5 without compromising the stereo separation...

radiotvnut · #14 03-03-2014, 10:45 PM

According to the schematic, the amp chassis contains two 6V6's in PP to drive the center channel and these are driven by a 12AX7 on the main amp chassis. There is a 6BQ5 for the L channel and another 6BQ5 for the R channel, both being driven by a 12AX7 that's hiding on the preamp chassis that contains the volume, balance, bass, and treble controls. There was also a version of this console that contained an AM/FM radio.

DavGoodlin · #15 03-04-2014, 07:52 AM

Quote:

Originally Posted by radiotvnut

According to the schematic, the amp chassis contains two 6V6's in PP to drive the center channel and these are driven by a 12AX7 on the main amp chassis. There is a 6BQ5 for the L channel and another 6BQ5 for the R channel, both being driven by a 12AX7 that's hiding on the preamp chassis that contains the volume, balance, bass, and treble controls. There was also a version of this console that contained an AM/FM radio.

Oops, I made an assumption there were no more tubes than the photo shows.
The P-P 6V6 are obvious. I have a Motorola stereophonic amp chassis from 1961, there are three or four 6BQ5 (bass channel is PP?) IIRC.
Im looking forward to hearing how yours sounds.