old amp inputs

[greggfarnham]

My son has an ancient amp (mid 70's) that he wishes to connect an old CD player to. The amp has inputs labelled; tuner, mic, xtal, mag, tape. But I'm unsure which is the right one to put the CD into. Please give us the benefits of your experience and advise.

[Dozuki]

Tuner or Tape would be fine. not sure what xtal or mag are, but definatley not the mic input as this should have a preamp built into it.

-D.

[karma]

my old tube amp has mag its for phono

[Centauri]

mag & xtal are turntable inputs for magnetic or crystal pickups. These have EQ for vynal discs and are not suitable for CD.

As mentioned, tuner or tape inputs will be fine.

Cheers

[greggfarnham]

Thanks, I thought tape would be fine but didn't want to bust anything!
He's now all go with the tape input and we'll NEVER hear the end of it!

[planet10]

Originally posted by Centauri
mag & xtal are turntable inputs for magnetic or crystal pickups. These have EQ for vynal discs and are not suitable for CD.

xtal should have little or no EQ and about the same gain as an aux in, so it would do in a pinch.

dave

[sreten]

the Xtal input will have the right voltage sensisitivity, ~ 1V,
but the high input impedance (1Mohm ?) will compromise
noise levels when used with CD.

sreten.

[Ouroboros]

Originally posted by sreten
the Xtal input will have the right voltage sensisitivity, ~ 1V,
but the high input impedance (1Mohm ?) will compromise
noise levels when used with CD.

sreten.

Although this will be true for the input if nothing is connected to it, the low output impedance of the CD player will swamp the high-Z input so it shouldn't affect the noise.

I have my doubts though whether an input designed to take an old crystal or ceramic pick-up cartridge will cope with perhaps 2V rms from a CD player.

[sreten]

Originally posted by Ouroboros



Although this will be true for the input if nothing is connected to it, the low output impedance of the CD player will swamp the high-Z input so it shouldn't affect the noise.

I have my doubts though whether an input designed to take an old crystal or ceramic pick-up cartridge will cope with perhaps 2V rms from a CD player.

Whilst true in terms of source resistance noise, the actual circuit
will not be optimised for low noise with this source resistance.

The xtal input is more likely to be able to cope
with 2Vrms than the tuner or tape inputs.

sreten.

[sreten]

Originally posted by Ouroboros



Although this will be true for the input if nothing is connected to it, the low output impedance of the CD player will swamp the high-Z input so it shouldn't affect the noise.

I have my doubts though whether an input designed to take an old crystal or ceramic pick-up cartridge will cope with perhaps 2V rms from a CD player.

Whilst true in terms of source resistance noise, the actual circiut
will not be optimsed for low noise with this source resistance.

The xtal input is more likely to be able to cope
with 2Vrms than the tuner or tape inputs.

sreten.