Author Topic: Which Magnavox model is this and starting pointers  (Read 811 times)

HiFiFun

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Which Magnavox model is this and starting pointers
« on: August 21, 2016, 05:18:43 PM »
Hello all,
I've received a Magnavox model CP291, Amp 128E that someone wants
repaired.
This is my first time to have a Magnavox project. I could not locate the amp/model
after looking on the forum here.
I will need the schematic, if anyone has it.
I also will appreciate knowing which model record changer it has.

So, for a first timer working on a Magnavox, any known roadblocks/bottlenecks/common probs
that I should expect will be Greatly appreciated.
I'm not averse to research, so point me to wherever I need to go on the forum.
This unit I bet will sound very good when working again.
I'm excited to start on this good looking hi-fi !
Thanks,
HFF

HiFiFun

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Re: Which Magnavox model is this and starting pointers
« Reply #1 on: August 21, 2016, 05:58:16 PM »
Further research found in 1956 Magnavox catalogue: this looks like a "Magnasonic".
I don't see any tweeters in the cabinet !? From the catalogue, there should be two.
Are they hidden somewhere ? Ha !!
Oh, wait, I see in the catalogue it says "plus two coaxially mounted 5" high-frequency speakers..."
So, I assume the 12 inch woofers have the tweeters mounted as two-way speakers.
Sorry to be answering my questions as I go along, ha ha !
HFF

AlexanderMartin

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Re: Which Magnavox model is this and starting pointers
« Reply #2 on: August 21, 2016, 09:20:23 PM »
Bottlenecks to list that are easily remedied:
Replace the coupling capacitors with .1 250v caps. This will give the amp a bit better frequency extension. Coupling caps go from the plate of the preamp tube to the grid of the power tube (schematic should have it marked.) Do not replace the input caps with those if they have the frequency divider.

To me it looks like those are fullrange magnavox speakers, someone more knowledgeable can inform us both on them. However, replacing the caps with Dayton or Solen caps would be a good move.


Ken Doyle

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Re: Which Magnavox model is this and starting pointers
« Reply #3 on: August 22, 2016, 07:51:31 AM »
The record changer appears to be a Collaro RC456.

HiFiFun

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Re: Which Magnavox model is this and starting pointers
« Reply #4 on: August 22, 2016, 12:02:27 PM »
Thanks Alex and Ken.
I found a schematic for Magnavox AMP 128 A/B ca.1954.
I will check it against the 1956 E amp's innards.

I'm going to post separately in the Record Changer department for
questions re: Collaro RC456.

HiFiFun

Harbourmaster

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Re: Which Magnavox model is this and starting pointers
« Reply #5 on: August 22, 2016, 04:47:13 PM »
There are indeed 5" speakers mounted in front of the 12's in a "coaxial style" arrangement.
-- Aloha, Ken

No Console Left Behind!

HiFiFun

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Re: Which Magnavox model is this and starting pointers
« Reply #6 on: August 22, 2016, 04:53:50 PM »
Hi Ken,
There are indeed 5" speakers mounted in front of the 12's in a "coaxial style" arrangement.

I figured that was the case when I also noticed extra speaker wires that
travelled through a channel cut under the woofers. These wires "disappear"
in front of the woofers.

HFF


TC Chris

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Re: Which Magnavox model is this and starting pointers
« Reply #7 on: August 22, 2016, 10:52:13 PM »
I've got a 1956 Magnasonic just like that, except that the veneers are mahogany.  The cone tweeters are mounted in front of the 12" woofers, as noted.  Mine was my grandmother's, a gift from my father and his brothers it seems.  Many years ago when she was still alive the cartridge gave out and i replaced it with some generic ceramic turnover  device.

Chris Campbell