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Beomaster 1200 Gramophone input? Warning! stupid question inside!

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Laban666
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Laban666 Posted: Mon, Jul 1 2013 11:52 PM

This might be a VERY stupid question, but anyway....

I read in the Service manual that the Gramophone input is:

Low inpedance: 4mV - 1000Hz / 47 kohms

High impedance: 200mV - 1000HZ / 470 kohms.

 

And the Tape recorder input is:

200mV - 1000HZ / 470kohms.

 

So, if I switch the gramophone input to high impedance, will the gramophone and tape input be exactly the same?? So I can connect a CD or a tape-player to the gramophone input?

vikinger
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The gramophone input has a compensating RIAA preamplifier that allows for the non-linear output from vinyl records.

This input will not work for tape or CD players which have linear outputs.

Graham

Peter
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Peter replied on Tue, Jul 2 2013 9:39 AM

Actually not so sure about this. The switch was originally designed for crystal pick ups which had a relatively flat output as they work on amplitude rather than velocity. To be fair, the frequency response is nothing like flat in Hi-Fi terms but it pre-dates  this! The high output should therefore switch away from the RIAA - my electronics ability is next to nothing but that would appear to be shown in the circuit diagram.

So the input could be used with a CD player.

I think! Big Smile

Peter

tournedos
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The levels are compatible, so just try it. If the frequency response is not right, you'll hear it immediately - if it is, enjoy Smile

(actually I believe the crystal pickup mode should be flat)

--mika

BO
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BO replied on Tue, Jul 2 2013 9:46 AM

Yes they will be the same. You can use it for a CD.

Lycka till!

//Bo.
A long list...

vikinger
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OK. I'll stand corrected. My BM1200 is packed away at the moment, but I cannot actually remember seeing a switch for the gramophone input! 

Was it something incorporated in just the first BM1200 models?

Graham

 

Laban666
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Laban666 replied on Tue, Jul 2 2013 11:47 AM

I don't know, but I have 5 BM1200 and 2 BM1001 and they all have the high/low switch.

Peter
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Peter replied on Tue, Jul 2 2013 1:25 PM

5 1200s! Do you know Martin? Smile

Peter

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