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How to select replacement 33rpm changer for 47-1230 - Printable Version

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How to select replacement 33rpm changer for 47-1230 - Marsupial - 04-15-2012

When I started to work on my console radio, two comments came out very frequently...

first "that's a high tube count, this a hard project for a beginner" and I must admit it is true, its more challenging than smaller ones (that I got afterwards. I've seen schematics with less than 15 caps!)

Then, "those dynamic cartdriges are impossible to find, you might never get this changer to work again".

To be honest, I need to agree again, but more even is the fact that I don't own any 78rpm records and have not access to many, while I really like 33rpm LPs. (and singles too, but that's another story)

Therefore, I would like to know if it is possible to replace the changer for a 33RPM one, I don't really care about the style being that it goes "inside" the radio, but would like it to not look too much out of place.

It would need to be compatible, both electronically and mechanically -
electronically: needs to be compatible with the phono input of the radio;
mechanically: would be awesome if I could bolt it in the bolting brackets of the D10-A without having to alter the frame of the radio.

So... how do I find such a replacement radio... and more even, where do I find it?

any help appreciated. I'd hate to put a 70s turntable in that 40s wooden console.

RE: How to select replacement 33rpm changer for 47-1230 - codefox1 - 04-16-2012

(04-15-2012, 06:54 PM)Marsupial Wrote:  When I started to work on my console radio, two comments came out very frequently...

first "that's a high tube count, this a hard project for a beginner" and I must admit it is true, its more challenging than smaller ones (that I got afterwards. I've seen schematics with less than 15 caps!)

Then, "those dynamic cartdriges are impossible to find, you might never get this changer to work again".

To be honest, I need to agree again, but more even is the fact that I don't own any 78rpm records and have not access to many, while I really like 33rpm LPs. (and singles too, but that's another story)

Therefore, I would like to know if it is possible to replace the changer for a 33RPM one, I don't really care about the style being that it goes "inside" the radio, but would like it to not look too much out of place.

It would need to be compatible, both electronically and mechanically -
electronically: needs to be compatible with the phono input of the radio;
mechanically: would be awesome if I could bolt it in the bolting brackets of the D10-A without having to alter the frame of the radio.

So... how do I find such a replacement radio... and more even, where do I find it?

any help appreciated. I'd hate to put a 70s turntable in that 40s wooden console.

I't suggest a 1960's vintage VM (Voice of Music) changer. Millions upon millions were made, so they are cheap, work reasonably well, and you can still get some parts for them.

Of course turntables are still being made (not changers that I know of,) or rock bottom scrounge a turntable from the curb from one of those plastic solid state abominations and make if fit into your cabinet.

RE: How to select replacement 33rpm changer for 47-1230 - Ron Ramirez - 04-16-2012

My suggestion would be to use a changer from an early 1950s Philco console. The 1950 and newer changers will have a single tone arm and three speeds (33-1/3, 45 and 78 rpm).

Pros: Same brand, will look more "natural" in the set, may even mount the same as the 1947 changer which would be a definite plus.

Cons: The newer changer will use a ceramic cartridge with a higher output. This would overload your set's built-in phono preamp. You would want to change the cartridge anyway to one capable of playing 0.7 mil stereo records; the older LP styli were 1 mil and may damage your records.

So you are looking at some sort of modification, no matter which way you go.

It's worth the effort, though, if you really like the radio and want to keep it.

RE: How to select replacement 33rpm changer for 47-1230 - codefox1 - 04-16-2012

(04-16-2012, 11:44 AM)Ron Ramirez Wrote:  My suggestion would be to use a changer from an early 1950s Philco console. The 1950 and newer changers will have a single tone arm and three speeds (33-1/3, 45 and 78 rpm).

Pros: Same brand, will look more "natural" in the set, may even mount the same as the 1947 changer which would be a definite plus.

Cons: The newer changer will use a ceramic cartridge with a higher output. This would overload your set's built-in phono preamp. You would want to change the cartridge anyway to one capable of playing 0.7 mil stereo records; the older LP styli were 1 mil and may damage your records.

So you are looking at some sort of modification, no matter which way you go.

It's worth the effort, though, if you really like the radio and want to keep it.

Agree, but earlier turntables act more like lathes than players on unobtanium records. Even the most recent vinyl is good for no more than 50 good plays, 100 at most. Like everything else, it depends.

RE: How to select replacement 33rpm changer for 47-1230 - Ron Ramirez - 04-16-2012

Ah yes, tracking weight - another factor to weigh (no pun intended).

Marsupial, do you have a migraine yet from all of these suggestions? Icon_wink

RE: How to select replacement 33rpm changer for 47-1230 - Marsupial - 04-17-2012

I do have a migraine, but only because I am working long hours. Bring'em on suggestions, I like that Icon_biggrin

I like the ideas, both voice of music and later Philcos. I definitely like the possibility of a 50s Philco changer that might fit in the mounting brackets of the radio. That is definitely a plus.
How does one go about changing the cartdrige?

and... do I get a transformer to adapt to the radio's input?

BTW I have been playing music out of other systems (radio, computer, mp3 player) directly into the phono input (it has an RCA-compatible plug) for a while - testing the recaped amp... I was under the impression that the arm of the D10 was stronger than modern ones. It does have its own transformer.

Next question is "where to find it"...? I have been looking at flea markets. While I can get a ton of 70s turntable, there's nothing pre-1960. The 70s ones aren't too bad, but those turntable where made to be HUGE and standalone. I doubt I can frankenstein it properly to my needs.
Oh, and I won't settle for a modern plastic turntable. The look, quality both mechanical and audio won't suit my needs. If I am to replace the changer, I'd like something that holds well.

RE: How to select replacement 33rpm changer for 47-1230 - Arran - 04-18-2012

Another possibilty would be to either replace the original cartridge for a ceramic type, there were some universal replacement types sold with adapter plates to fit different tone arms, or to have the original Rochelle salt crystal element replaced with a ceramic element.
Regards
Arran

RE: How to select replacement 33rpm changer for 47-1230 - Marsupial - 04-18-2012

Arran... do you mean converting the original changer to 33rpms?

If that's possible, I'm all for it. really.

RE: How to select replacement 33rpm changer for 47-1230 - Arran - 04-18-2012

(04-18-2012, 01:17 PM)Marsupial Wrote:  Arran... do you mean converting the original changer to 33rpms?

If that's possible, I'm all for it. really.

No I don't think it's possible to convert a 78 rpm only player to a 33 1/3 rpm only player without being a machinist. I meant that you could rebuild the original cartridge with a new element so the machine will actually work or replace the original cartridge with a newer one with a ceramic element inside.
Regards
Arran