amplifier input sensitivity - cd player output

[thes]

Hello
the manual of my amplifier states that the input sensitivity of the cd/tuner input is 150mV (40k ohms) at 1 kHz.
The outpt of my cd player is 2 V at 0 db. Output impednce is 600 ohms.

Can someone explain me how to know if this is a good match? The problem is that i can't read these specs.Can someone explain me how to properly match a cd player to an amp?
The problem is that the input of the amp is in mV and the output of the cd player is in V...the output of the cd player semms to be indeed too high!:nono:

 

[whoaru99]

It will be fine.

The input sensitivity doesn't in any way mean that's the maxium or limit you can put in. What it really means is that's the minimum level necessary to get full power out of the unit at a certain point of the volume control. You can even put in less, but you might not get full rated power out, or might have to turn the volume knob beyond the reference point (whatever that is).

Also, the CD output spec being 2V means 2V output at 0dBFS or 2V with the loudest signal that can be recorded on the disk. The nominal level (depending, I suppose, on the nature of the music) usually will be less than that. With regard to the impedances, 600 ohms feeding 40,000 ohms is just fine. The general rule of thumb is to have a minimum of 1:10 ratio. You're at 1:67, well within (or beyond?) that.

 

[bowtie427ss]

The outpt of my cd player is 2 V at 0 db.

That is the maximum output capability. The actual output for any given disc will be determined by the level set on the disc during mastering. The actual output from your CD player during play will generally be much less than 2V, usually an average of a couple hundred mV or so.

the input sensitivity of the cd/tuner input is 150mV (40k ohms) at 1 kHz.

That is the minimum input required for the amplifier to be able to produce full output.

 

[Jon_Logan]

Make sure your CD player has a variable output control (and start low). The output of the CD player can easily drive the power amp into clipping.

 

[Hyperion]

Make sure your CD player has a variable output control (and start low). The output of the CD player can easily drive the power amp into clipping.

+1 on that - giving it the full (un-attenuated) output from the CD player must mean this is more likely :scratch2:

 

[bowtie427ss]

The output of the CD player can easily drive the power amp into clipping.

I don't see where the OP is driving power amp inputs directly from CDP outputs, he mentions a CD/tuner input. Looks to me like the OP is referring to an integrated where the actual amplifier section is going to be "buffered" by the preamplifier section.

But, that is not to suggest that it isn't possible to damage something by over-driving that input.

 

[Jon_Logan]

You're right.

I saw that ".. match to amp" line and thought there was a direct connect. .....which I do not have a problem with if you only have a CD player as a source.

 

[Hyperion]

My CDP has a 2v fixed output and a variable output - the volume control on the amp has to be set ridiculously low if I use the 2V output into the AUX input.

Fed from the variable output of the CDP into the AUX of the amp, with the output turned down, I get a useful volume control position on the amp with useful gain steps.

That's why I +1'ed it.

Just saying...

 

[thes]

Ok,thanks everybody.And yes,i'm using an integrated amp,not a power amp.On my cd player is possible to decrease the output of max 12db,maybe could be useful but i don't think it's possible to feed a power amp that way! :-(

 

[whoaru99]

Sure, you could put in an attenuator circuit or in-line attenuators but unless this is actually causing a problem such as trying to increase the resolution of the volume adjustment there really isn't any reason to.

 

[slow_jazz]

I usually leave my muting button on when playing cd's.

Gives me more room for adjustment.